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  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Wednesday, 9 January, 2013

    Forecasts for Ireland


    Situation: Forecast models have been shifting around considerably since my previous forecast and during the day on Tuesday the general consensus was heavily towards much colder weather next week ... now I find that that change has been partially but not totally reversed. We are also seeing a role reversal of leading models similar to what happened in December when there was a rather similar threat. This is all stated to explain my decision to retire just kidding to hedge my forecast outlook for next week because the outcome most likely is transitional, not a full-on cold spell and not a complete return to mild either. I think we're dealing with an uncertain situation where percentage chances are needed to give some realistic guidance. But I do continue to believe that sooner or later, the U.K. and Ireland can expect spells of severe winter weather. If that begins next week, it may back off for a time before returning in stronger concentrations. The timing is not the only factor to consider, people would be wise to prepare for a wintry period of some length given the combination of evident risk and ongoing stratospheric warming events. This concern would not be reduced if next week's cold happens to be downgraded later in the forecast period.

    TODAY ... Widespread fog and frost, icy road conditions, giving way gradually to sunshine in some places, but staying rather cold, highs 2-6 C for most, about 8 C around the southwest coastal districts.

    TONIGHT ... Increasing cloud, frost and fog may return shortly after sunset in Ulster and Leinster, but cloud should prevent that in parts of Connacht and Munster, then sleet or rain will spread in, with snow possible in higher terrain (about 300m or higher) ... 5-10 mm of rain or equivalent will hit most places in the south and west before morning, lows -2 to +3 C.

    THURSDAY ... The band of sleet or rain will weaken and move further east, followed by mostly cloudy skies and rather cold temperatures throughout, highs about 4-7 C.

    FRIDAY ... A cold, frosty start in most areas, some freezing fog and icy roads again, lows -3 to +2 C, then cloudy with light rain perhaps starting as wet snow or sleet especially in higher parts of northwest and Kerry. It may stay dry most of the day in the east except for a few isolated wintry showers in weak streamers from the Irish Sea. Highs 4-7 C.

    SATURDAY ... Periods of rain at lower elevations, sleet or snow higher up, cold although somewhat milder in the southwest, lows 2-4 C and highs about 5 or 6 C but 8-10 C possible in southwest.

    SUNDAY ... Variable cloud, further showers mixing with wet snow in Ulster and possibly other places, cold but still generally above freezing in the range of 3-6 C. West coast could warm up slightly in a northwest flow to 8 C.

    OUTLOOK ... As mentioned in the situation report, the outlook is rather uncertain with a battleground scenario developing, and I currently estimate that for most of next week, the chances of deep cold and snow are about 30 per cent, modified cold with mixed precipitation about 50 per cent, and milder intervals about 20 per cent. Whatever happens, it is likely to be mostly cloudy with temperatures quite likely on a strong gradient from cold in Ulster to somewhat milder in west Munster, and in the range of -1 to +6 C across the country. The details will become clearer as we get closer to the period, and beyond next week, there are some indications of a brief return to milder weather followed by a more severe cold spell than what we're probably going to see next week.


    Forecasts for Britain

    TODAY ... Cloud departing from southeast with the last of any drizzle, otherwise a clear and in places frosty start except for locally dense fog and some icy roads in north and west ... warming up slightly under weak sunshine to about 5-8 C by afternoon but some pockets of 2-4 C may persist.

    TONIGHT ... Widespread ice fog, icy roads ... lows -5 to -2 C except near freezing to 4 C in outer coastal margins and in greater London.

    THURSDAY ... Increasing cloud, some sleet or rain developing in parts of Wales and southwest England, rather cold with highs 4-7 C.

    FRIDAY ... Variable cloud, morning frost or fog, lows near -3 C and highs near 4 C, some mixed wintry showers could develop in eastern districts.

    WEEKEND OUTLOOK ... Intervals of sleet or snow with rain near sea level in south and west. Highs 1-4 C. Moderate east winds developing and some wintry showers over higher ground in east and north. Same general uncertainty for next week although the odds are tilted more towards severe cold in eastern Scotland and northeast England and heavy snow is quite possible at times there.

    North American forecasts

    Just a little more active now as rain over the south central states expands and moves northeast, and Pacific fronts become more active, bringing outbreaks of heavy rain at low elevations near the coast and heavy snow inland. A rather mild weak chinook pattern is developing over Montana and Alberta with outbreaks of 3-5 cm snow across parts of central and northern prairies. Another weak system is drifting east through the Great Lakes bringing lake-enhanced flurries to some places, but the general trend in the eastern U.S. is milder with highs close to 10 C in NYC and 15 C in Washington DC, trending to 20 C in Atlanta and 25 C in Miami.

    My local weather on Tuesday was wet to say the least, I estimate that over 50 mm of rain fell and some sidewalks and roads are flooded, meanwhile there are reports of local creek and drainage ditch overflows in the region. Above 600 metres heavy snow is closing some mountain highways and bringing very good ski conditions to local resorts.

    For Ireland once again, I would expect guidance to keep shifting so keep in mind that anything beyond Sunday is probably going to remain subject to change for a couple more days at least.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Thursday, 10 January, 2013

    Forecasts for Ireland


    Situation update: Discussion yesterday remains valid ... models do not seem much closer to a definitive call on next week's cold (or snow) potential and I continue to think the outcome will be somewhat marginal as well as regionally or elevation-based ... see yesterday's post for that discussion.

    TODAY ... A band of sleet or rain will move gradually eastward, somewhat milder in parts of Munster where highs could reach 8-10 C, remaining rather cold elsewhere with highs 4-7 C ... rainfalls of about 3-5 mm and some sleet or snow at higher elevations ... wind directions will vary with passage of the weak trough but later may return to an easterly direction.

    TONIGHT ... Partly cloudy to overcast, cold ... a few clear spots could fall below freezing which will lead to frost and ice fog most likely around inland northeast from Meath to central Ulster. Lows -3 to 0 C in the north and east, but 3-5 C in Munster where light rain may resume after midnight.

    FRIDAY ... A cold, frosty start in most areas, some freezing fog and icy roads again, temperatures rather slow to rise above freezing, then cloudy with light rain (4-7 mm by evening) perhaps starting as wet snow or sleet especially in higher parts of the northwest and Kerry. It may stay dry most of the day in the east except for a few isolated wintry showers in weak streamers from the Irish Sea. Highs for most about 4-7 C, could be closer to 8-9 C in coastal southwest.

    SATURDAY ... Periods of rain (10-15 mm possible in south) at lower elevations, sleet or snow higher up, cold although somewhat milder in the southwest, lows 2-4 C and highs about 5 or 6 C but 8-10 C possible in southwest. Moderate east winds will develop in central counties and there could be mixed wintry showers with any streamers that develop.

    SUNDAY ... Variable cloud, further showers mixing with wet snow in Ulster and possibly other places, cold but still generally above freezing in the range of 3-6 C. West coast could warm up slightly in a northwest flow to 8 C.

    MONDAY ... Cloudy, rather cold in east and north, chance of sleet or wet snow, somewhat milder in south and west with showers of rain more likely there, highs in range of 2-7 C from northeast to southwest.

    TUESDAY ... Further mixed precipitation likely, possible frontal boundary in northeast could separate snow from rain, highs in range 1-6 C.

    WEDNESDAY-THURSDAY ... This period looks rather stormy and could bring heavy rain in southwest, mixed precipitation in some central regions and snow in northeast, but details are uncertain.

    FURTHER OUTLOOK ... A colder spell with more widespread snow and sub-freezing temperatures is possible around Friday 18th but that could be followed by another mild spell within a few days, and to continue my theme, the coldest part of winter could lie beyond that into February.


    Forecasts for Britain

    THURSDAY ... Increasing cloud, some sleet or rain developing in parts of Wales and southwest England, rather cold with highs 4-7 C.

    TONIGHT ... Cloudy with some ice fog developing in valleys outside of larger towns and cities, lows -2 to +3 C, light winds.

    FRIDAY ... Variable cloud, morning frost or fog, lows near -3 C and highs near 4 C, some mixed wintry showers could develop in eastern districts.

    WEEKEND OUTLOOK ... Intervals of sleet or snow with rain near sea level in south and west. Highs 1-4 C. Moderate east winds developing and some wintry showers over higher ground in east and north. Same general uncertainty for next week although the odds are tilted more towards severe cold in eastern Scotland and northeast England and heavy snow is quite possible at times there. If Ireland is in a battleground situation then that may extend into south Wales and southern England but it's more likely that from the Midlands north it would be on the colder side with snow more certain.


    North American forecasts

    Outbreaks of light snow in parts of western Canada as a ridge builds over the coast bringing welcome sunshine and highs near 6 C. South central states are still experiencing heavy rainfalls and outbreaks of severe storms around Alabama and Mississippi. The mild, dry spell continues in the northeast with a bit of light rain edging closer to the region by tonight.

    My local weather on Wednesday was cloudy but dry and rather mild with highs near 10 C.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Friday, 11 January, 2013

    Astronomy note: Later today, new moon is timed for 7:44 p.m. a few hours after sunset in Ireland, but around mid-day in my location in western Canada.

    The weather situation remains rather uncertain but the models seem to be converging on a moderately cold outcome rather than anything particularly severe, for the time being. I continue to think that more severe cold will eventually develop in perhaps 2-4 weeks from now. ALERT for some icy roads in counties between Dublin and central Ulster now to 1030h.

    Forecasts for Ireland

    FRIDAY ... A cold, frosty start in most of Leinster and Ulster, with some freezing fog and icy roads until about 1030h, temperatures rather slow to rise above freezing, then cloudy with light rain (4-7 mm by evening) perhaps starting as wet snow or sleet especially in higher parts of the northwest and Kerry. It may stay dry most of the day in the northeast except for a few brief intervals of drizzle ... highs for most about 4-7 C, closer to 8-10 C in coastal southwest.

    TONIGHT ... Sporadic light rain heavier in south coastal districts where 10 or 15 mm possible, otherwise 3-7 mm, some mixing with wet snow or sleet at higher elevations, cold except near south coast. Lows 1-4 C but 5-7 C near south coast.

    SATURDAY ... Periods of rain (a further 5-10 mm possible in south) at lower elevations, sleet or snow higher up, cold for most regions although somewhat milder in the southwest, highs about 5 or 6 C but 8-10 C possible in southwest. Moderate east winds will develop in central counties and there could be mixed wintry showers with any streamers that develop.

    SUNDAY ... Another rather cold morning with lows -2 to +3 C and local freezing fog, icy roads ... during the day, variable cloud, further showers mixing with wet snow in Ulster and possibly other places, cold but still generally above freezing in the range of 3-6 C. West coast could warm up slightly in a west to northwest flow to 8 C.

    MONDAY ... Cloudy, rather cold in east and north, chance of sleet or wet snow, as a band of mixed precipitation drops south through Ulster becoming mostly rain as it reaches milder regions further south ... morning lows generally around freezing, coldest in clear pockets inland south (near -2 C there) and highs in range of 4-8 C from north to south.

    TUESDAY ... Further mixed precipitation likely, possible frontal boundary in northeast could separate snow from rain, highs in range 1-6 C.

    OUTLOOK ... Model uncertainty prevails again, mid-week seems likely to remain on the colder side of normal but guidance is split between solutions of clear and cool high pressure or mixed wintry showers northeast to rain southwest in weak frontal disturbances. I think the latter is more likely although the European model has begun to feature stronger high pressure with this morning's guidance. What is more interesting, possibly, is the slow advance west of really cold air over Russia; that's what we are monitoring very closely as it could hold the key to any more intense winter weather in about 2-4 weeks (but with some chance of earlier arrival and also the possibility that it won't move this far west).

    Forecasts for Britain

    FRIDAY ... Variable cloud, morning frost or fog, lows near -3 C and highs near 4 C, some mixed wintry showers could develop in eastern districts.

    TONIGHT ... Light rain in southwest England and south Wales, trending to snow on hills above 400m, cold elsewhere with some freezing fog and icy roads, lows in the rain about 2-4 C but as cold as -4 C further north and east.

    WEEKEND OUTLOOK ... Intervals of sleet or snow with rain near sea level in south and west. Highs 1-4 C. Moderate east winds developing and some wintry showers over higher ground in east and north. The somewhat milder air returning to Ireland on Monday will push into western districts but colder air will remain over central and eastern regions so that any precipitation will likely be sleet or snow except near westerm coasts. Mid-week quite uncertain as to precipitation but likely to be cold with east winds and probably some snow in higher parts of east-central England, possibly some sunshine at times in Scotland, highs generally 2-4 C and sharp frosts at night. There is still some chance of a more severe cold and snow outbreak in eastern Britain towards the middle or end of next week.

    North American forecasts

    Heavy snow in Newfoundland with strong northeast winds, 30-40 cm potential in the capital city of St John's. Clear and cold further west trending to cloudy and mild in the Great Lakes and northeast U.S., rain arriving in central and western Great Lakes on southerly winds, highs 10-13 C (record highs are around 17 C in this region). The milder air is streaming north ahead of a developing snowstorm for Manitoba and western North Dakota, Saskatchewan and parts of eastern Montana, 20-40 cm may fall in strong northerly winds there, as temperatures fall to -15 C (from current -3 C in Winnipeg). Heavy rain over the south central states will be drawn into this stronger system around Illinois and Indiana, but some will head into Georgia and the Carolinas. Highs near 20 C are likely ahead of this complex frontal system around Washington DC (records there are closer to 25 C). Meanwhile, on the west coast, fronts moving inland are mixing with cold air in place and turning rain to snow later today except very close to sea level.

    My local weather on Thursday was a pleasant sunny change from the usual cloud and rain ... and the high was about 7 C but this evening it felt colder than past nights, around the freezing point.

    Just a note on another global weather event of some interest, the strong storm that hit the eastern Mediterranean and brought snow to Jerusalem, is now located in Iraq but it sent unusual warmth north into Afghanistan and Uzbekistan where Thursday's highs were into the 20s. That over-running warm air is setting off a vast blizzard further north across the steppes of central Asia (Russia-Kazakhstan) where Siberian cold air is deeply entrenched. In western Siberia it was closer to -20 C.

    This map will update around 1500h, if you check it before then you will see Thursday's observations, after that, Friday's (in the Middle East region)

    http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/synNNWWneareast.gif

    (the map time is 12z or 1200h GMT and this site usually updates at 1430h ... if you want to see more global maps, bookmark this site and strip out the last part of the address to get a menu for other continents ... European maps appear for every 6h with the same lag time to updates).


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Saturday, 12 January, 2013

    Forecasts for Ireland



    TODAY ... Periods of rain (a further 5-10 mm possible in south) at lower elevations, sleet or snow higher up at elevations above 300m, cold for most regions although somewhat milder in the southwest, highs about 5 or 6 C but 8-10 C in south and west Munster. Moderate east winds 30-50 km/hr will develop in central counties and there could be mixed wintry showers with any streamers that develop.

    TONIGHT ... Mixed or sleety showers becoming less frequent and more confined to coastal margins, cold especially inland where lows -3 to +1 C and some icy roads likely ... winds in exposed locations E-NE 20-40 km/hr ... some wet snow may fall in higher parts of north.

    SUNDAY ... Another rather cold morning with local freezing fog, icy roads ... during the day, variable cloud including some brief sunny intervals, further showers mixing with wet snow in Ulster and possibly other places, cold but still generally above freezing in the range of 3-6 C. West coast slightly milder in a west to northwest flow to 8 C. Moderate NE winds backing to NW later in the day.

    MONDAY ... Cloudy, rather cold in east and north, chance of sleet or wet snow, as a band of mixed precipitation drops south through Ulster becoming mostly rain as it reaches milder regions further south ... morning lows generally around freezing, coldest in clear pockets inland south (near -2 C there) and highs in range of 4-8 C from north to south. Some 3-5 cm snowfall accumulations are possible in higher parts of Connacht and Ulster.

    TUESDAY ... Further mixed precipitation likely, possible frontal boundary in northeast could separate snow from rain, highs in range 1-6 C. Some model guidance indicates potential for 5-15 cm snowfalls in east Ulster and north Leinster but this is currently quite uncertain, as is the eventual location of any frontal zone.

    WEDNESDAY to FOLLOWING WEEKEND ... Model guidance is very "mixed" to say the least, and the most likely outcome seems to be cold dry weather trending to milder by the weekend, as a weak arctic high develops mid-week. In that scenario, lows could fall to about -5 C with severe and persistent frost and some ice fog, and highs 2-5 C but also some wintry sunshine especially in coastal south and west. Later in the period highs would likely rise to about 8-10 C. Other guidance is suggesting mixed precipitation as further disturbances could come out of the north or northwest and prevent that high from swelling up enough to dominate. I suspect there will be a bit of everything in the mixed guidance and a general slow warming trend that will peak later in the month before a more powerful westward push of very cold air that so far is mostly hanging back over Russia with a weak forerunner now moving towards the Baltic.

    Forecasts for Britain

    TODAY ... Outbreaks of light rain across the southwest and south Wales, mixed or sleety on higher ground with snow accumulating on peaks ... a few rather isolated mixed showers further north and east with mostly cloudy skies and moderate SE winds 30-50 km/hr, rather cold with highs 3-6 C.

    TONIGHT ... Rain changing to sleet or wet snow in south, clear intervals central and very cold in some places (lows -2 to -6 C), rain or snow moving south into Scotland, lows 2-4 C.

    SUNDAY ... Bands of rain, sleet and hill snow moving south, highs 4-7 C at low elevations, 2-4 C on hills. Some wintry sunshine in a few parts of the south.

    MONDAY to WEDNESDAY ... Snow and colder weather likely for eastern England and Scotland, variable cloud and isolated wintry showers further west, highs in the range of -2 to +3 C east but 3-7 C west. Some severe frosts in central regions especially in Scotland.

    FURTHER OUTLOOK ... Cold and dry is most likely to prevail over weak and isolated outbreaks of snow or sleet, then a milder turn late in the week. Some lows around -7 C to -10 C during the cold spell Wed-Thurs.


    North American forecasts

    Further heavy snow in Manitoba spreading into northern Ontario, Minnesota, clearing and cold further west, and sleet to rain on the west coast from a weaker system moving inland there. Rain spreading northeast across much of the inland northeast states, Great Lakes region, mild to very mild, highs about 12-15 C trending to 20-25 C in the southeast. A cold front will drop temperatures sharply in the central plains states and the southwest will become unusually chilly (12-15 C) with scattered killing frosts in some key agricultural zones in southern California. Flurries over mountain ranges.

    My local weather on Friday was cold with morning sun, increasing cloud and sleet approaching now, high was about 3-4 C.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Sunday, 13 January, 2013

    Forecasts for Ireland


    ALERT for very icy road conditions in north-central counties as cloud and mist spread in over pockets of sub-freezing air trapped in low-lying areas, severe black ice is likely ... the good thing is that it's a Sunday and the flow of traffic may be a bit later to reach a peak, giving treatment some time to kick in and also perhaps allowing some of this black ice to thaw before some encounter it ... conditions should improve around 10:00h.

    Latest situation update: Our ongoing theme of a modified and somewhat regional cold spell seems to be coming into clearer focus now, and it is likely to turn quite cold both night and day mid-week, but this could fail to reach some parts of the south and west. There will also be increasing chances for snow at lower elevations through Tuesday and for part of Wednesday, after which cold high pressure should cut off the moisture and then milder air is likely to make a slow and rather lethargic return late in the week.

    SUNDAY .. Llocal freezing fog, icy roads in north-central counties, with mist and drizzle moving south from Ulster into parts of Connacht and Leinster ... during the day, variable cloud including some brief sunny intervals, then a second and heavier band of sleety showers mixing with wet snow in Ulster and possibly other places on higher terrain, highs mostly 4-6 C. West coast becoming slightly milder in a west to northwest flow to 8 C. Winds variable or north through east, backing to WNW later in the day, rather breezy by afternoon in coastal north and west (40-60 km/hr).

    TONIGHT ... Sleety showers ending, partial clearing, cold, ice and freezing fog returning to some inland districts. Lows about -3 C to near freezing.

    MONDAY ... Cloudy, rather cold in east and north, chance of sleet or wet snow, as a band of mixed precipitation drops south through Ulster becoming mostly rain as it reaches milder regions further south ... highs 4-8 C from north to south. Some early morning 3-5 cm snowfall accumulations are possible in higher parts of Connacht and Ulster and this snow could persist on higher slopes.

    TUESDAY ... Variable cloudiness and some bands of mixed wintry showers, as a frontal boundary from about Donegal to Wicklow could separate mostly snow in north and east from mixed showers including some rain in south and west, highs in range -1 to 3 C on cold side of this boundary, and 4-8 C on the milder southwestern side. Although the colder air could produce snow, its passage over the warmer Irish Sea might change precipitation types in some streamers to hail or even rain near sea level.

    WEDNESDAY ... Further mixed showers with snow potential in east coast counties, but trending to clear and cold later in the day, streamers increasingly confined to Wicklow and Wexford. Some heavy falls of snow over the two days could develop over hills in the southeast but for lower elevations this forecaster currently expects 3-7 cm amounts some of which may be slushy. Roads are likely to be very icy on medium to higher elevations all over the country except in the southwest where only higher elevations may see cold enough temperatures. At the same time, this may be only a marginal event near some coasts at sea level.

    THURSDAY ... Clear intervals, increasing high cloud, cold. Lows -4 to -7 C and highs 2-6 C mildest near west coast. Some persistent freezing fog during the morning in central inland counties. Light winds.

    FRIDAY ... Increasing cloud, rain or drizzle near west coast, milder. Lows near -2 C east, +3 C west and highs 7-10 C in developing southerly winds.

    OUTLOOK ... Next weekend seems likely to be unsettled and near normal in temperatures. Colder air may not stray very far from the region and could try to mount another assault during the next week, and a more severe cold spell is still quite possible for later this month or early-mid February.


    Forecasts for Britain


    TODAY ... Bands of rain, sleet and hill snow moving south, highs 4-7 C at low elevations, 2-4 C on hills. Some wintry sunshine in a few parts of the south.

    TONIGHT ... Mixed sleety showers moving through south, further showers in north and west, somewhat milder in west, lows 2-4 C there, around -1 C east and southeast.

    MONDAY to WEDNESDAY ... Snow (as much as 10-20 cm in east Midlands, east Anglia and Yorkshire, northeast England) and colder weather likely for eastern England and Scotland, variable cloud and isolated wintry showers further west, highs in the range of -2 to +3 C east but 3-7 C west. Some severe frosts in central regions especially in Scotland. The south coast may not get into the coldest east winds and may see mixed showers and 4-5 C, and Cornwall-coastal Devon could stay milder yet at about 5-8 C. Streamers of heavy snow seem likely to form off the North Sea on Tuesday and in the southeast again on Wednesday. Amounts will be heaviest around Cambridge, Lincoln and Sheffield towards Newcastle. London may see a sleety mix and some minor disruptions but an interval of heavier snow cannot be ruled out.

    FURTHER OUTLOOK ... Cold and dry is most likely to prevail over weak and isolated outbreaks of snow or sleet, then a milder turn late in the week. Some lows around -7 C to -10 C during the cold spell Wed-Thurs. Slowly warming up to near normal by end of the week.


    North American forecasts

    Very mild air across the eastern and southeastern U.S. will last one more day as a wave along the strong cold front ripples across the Ohio valley and lower Great Lakes bringing a rain-snow mix there. Highs reached a record 24C in Atlanta on Saturday and seem likely to be close to that again today, about 15 C in Virginia and 5-10 C in large cities of the northeast. Very cold air has pushed well south behind the front and is edging into north Texas and Arkansas today, some freezing rain may develop, but it remains quite mild closer to the Gulf coast. Unseasonably cold in the southwest states, currently about -20 C at the Grand Canyon (south rim) and Bryce Canyon in Utah, and near -10 C at somewhat lower elevations, not likely to rise above freezing all day over fresh snow cover, but about 10-13 C in Phoenix and Las Vegas, 15-17 C in Los Angeles and Palm Springs. Most of western Canada is also in the deep freeze near -30 C trending to near +4 C on the west coast, and largely dry with weak disturbances bringing light snow. The blizzards have moved away, the central plains storm is now over Hudson Bay and the Newfoundland storm spun around and went towards the Azores, drawing very cold air out over the western Atlantic. People are now digging out of these two storms under fairly calm and clearing weather.

    My local weather on Saturday was cloudy to start, then sunny and rather cold, highs only 2-4 C. Frosty out tonight (-3 C) under clear skies.


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  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Monday, 14 January, 2013

    Forecasts for Ireland


    ADVANCE ALERT for possible snowfalls of 5-15 cm in parts of central and southeast Ireland Tuesday night into Wednesday morning, as sleet or rain could turn to snow during the colder overnight hours. An elevation-based divide is likely but it may fall to levels close to the general terrain of inland counties (100-200m) before the event pulls away. Also, ALERT for possible icy road conditions at various times before and after this snowfall event.

    TODAY ... Cloudy with a few brighter spells around mid-day, rather cold in east and north, further mixed wintry showers could develop in gusty NW winds 40-70 km/hr coming inland across the north and west, amounts generally 2-4 mm or equivalent ... highs 4-8 C from north to south. Feeling very cold in the wind, and a chance of wintry conditions on higher slopes mainly above 350m.

    TONIGHT ... Clear intervals, less windy, very cold with some local frost and ice fog and some icy roads where untreated, lows -3 to +2 C.

    TUESDAY ... Variable cloudiness and some bands of mixed wintry showers, as a frontal boundary from about Galway to Waterford could separate mostly snow in north and east from mixed showers including some rain in south and west, highs in range -1 to 3 C on cold side of this boundary, and 4-8 C on the milder southwestern side. Although the colder air could produce snow, moisture drawn in from the Irish Sea as associated streamers could see a variety of precipitation types such as hail or even rain near sea level. The greatest risk for accumulating snow will come late Tuesday overnight into Wednesday in counties around Laois, Tipps, north Kilkenny and parts of Offaly, Meath, Westmeath as falling temperatures allow sleet to change to accumulating snow. East Ulster and parts of north Leinster may be outside this mixed precipitation band under partly cloudy skies. Watch for updates.

    WEDNESDAY ... Further mixed showers with snow potential in southeast and east coast counties, but trending to clear and cold later in the day, highs about 3-7 C from east to west, as any streamers become increasingly confined to Wicklow and Wexford. Some heavy falls of snow over the two days could develop over hills in the southeast (10-20 cm) but for lower elevations this forecaster currently expects 5-10 cm amounts some of which may be slushy. Roads are likely to be very icy on medium to higher elevations all over the country except in the southwest where only higher elevations may see cold enough temperatures. At the same time, this may be only a marginal event near some coasts at sea level.

    THURSDAY ... Clear intervals, increasing high cloud, cold. Lows -4 to -7 C and highs 2-6 C mildest near west coast. Some persistent freezing fog during the morning in central inland counties. Light winds.

    FRIDAY ... Increasing cloud, rain or drizzle near west coast, milder. Lows near -2 C east, +3 C west and highs 7-10 C in developing southerly winds.

    OUTLOOK ... The models give hints of further frontal boundary mixed precip with some snow potential through the weekend and much of the following week. I would estimate that there is about a 30% chance of severe cold and snow, 40% chance of mixed conditions and marginal events, and 30% chance of a more robust push of mild Atlantic air generally winning out. Eventually, I think a more severe wintry spell could materialize, although there is some potential in this set-up, a more organized westward push of bitterly cold Siberian air is always a possibility and much of this continues to lurk back to the east of Moscow although a small parcel was released in the past two days and is drifting across the Baltic now.


    Forecasts for Britain

    TODAY ... Partly to mostly cloudy, a few intervals of sleety showers or wet snow, quite cold with strong and gusty NW winds 50-80 km/hr, highs near 5 to 7 C south and 2 to 4 C north (except western Scotland 4-6 C).

    TONIGHT ... Some clear intervals, cold, a few isolated wintry showers, lows about -2 to +2 C.

    TUESDAY ... Some sunny intervals west, snow or sleet moving south and west from the North Sea inland into eastern England, some 5-15 cm snowfalls and locally bad road conditions ... highs 2-4 C but falling to -1 C in snow.

    WEDNESDAY ... Snow may become heavy in some eastern counties, mixed sleety showers in south with rain at times in Cornwall and south Wales, Devon. Snow amounts of 10-20 cm will be heaviest around Cambridge, Lincoln and Sheffield towards Newcastle. London may see a sleety mix and some minor disruptions but an interval of heavier snow cannot be ruled out. Highs about -1 C central to +4 C south. Scotland may see more sunshine than elsewhere with less windy conditions, after a severe frost to start the day.

    FURTHER OUTLOOK ... Cold and dry is most likely to prevail over weak and isolated outbreaks of snow or sleet, then a milder turn late in the week. Some lows around -7 C to -10 C during the cold spell Wed-Thurs. Slowly warming up to near normal by end of the week but with risk of further snow or sleet especially in central and eastern regions.


    North American forecasts

    Turning colder in the Great Lakes region but staying rather mild from about Washington DC south as weak fronts stall, and more rain develops turning to sleet over higher terrain in West Virginia and western North Carolina. Not quite as mild as the weekend in the southeast, about 15-18 C. The cold, dry weather moving south from central Canada will stall just north of the Gulf coast with outbreaks of freezing drizzle or sleet north of the front, rain and fog south of it. Continued unseasonably cold in the southwest states and mainly dry and chilly further north near the coast, but turning a bit milder in Alberta and Montana as a weak chinook develops and brings temperatures back up to near 2-4 C. This will set off light snow later and tonight further east and then a wave will run along the arctic front southeast allowing a new surge of very cold air to head south from the Northwest Territories towards Manitoba, Lake Superior and Wisconsin, reaching Chicago in about two days. This will overwhelm the northeast and bring a brief change to very cold weather later this week. Little if any snow will accompany the cold wave except where winds blow across open waters of the Great Lakes.

    My local weather on Sunday was dry and chilly, with increasing high cloud, and highs 3-5 C.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    UPDATE _ Mon 14 Jan 2013 _ 9:45 pm
    _____________________________________

    ALERT for possible snowfall in parts of south-central Ireland Tuesday night into Wednesday morning is currently more of a "watch" situation as conditions appear very close to marginal for elevations below 250m ... the main reason for concern is that the precipitation, which is likely to start in most places as rain or sleet, will be extending into the late overnight period when temperatures at higher levels cool down slightly and a marginal situation can produce snow, but my thinking at present is that the snow will develop mostly on higher slopes above 300m around midnight then start to appear lower down as the night goes on, so that by the end of the event there could be wet snow falling closer to sea level and accumulations at elevations above 200m, in the precip zone extending across central and southeast counties. Locations further west will not get cold enough for this transition except on higher summits in Kerry. Locations further north and east will be outside the precip zone, but in parts of Connacht the rain will move through before midnight and that also reduces the risk of snowfall despite some favourable elevations.

    Perhaps of more interest to many, Friday is looking somewhat more promising for snow in eastern Ireland as the stronger return of Atlantic mild air seems timed to run into a wedge of colder air rotating around what's left of the mid-week system, and that stronger frontal event will have higher moisture levels so there is a potential for 5-15 cm snowfalls, once again, elevation may become a limiting factor.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Tuesday, 15 January, 2013

    Forecasts for Ireland


    ALERT for icy roads in some inland locations this morning and again on both Wednesday and (more widespread) Thursday mornings. ALERT for possible 5-10 cm snowfalls mainly on higher terrain in eastern and northern counties tonight.

    Situation report: Tonight's weather event will be a messy marginal mix and there's some chance of a repeat on Thursday night as colder air is finally pushed some distance back from the region, but all of that pales in comparison to the potential for weather mayhem on Sunday as various models depict a very deep low heading in from the Atlantic on a path that will invite that colder air to get involved again. Whether this turns out to be heavy rain, a nasty mix or a snowstorm depends on various factors yet to be clarified on the models, but anything is possible and if this storm were to veer north, very strong winds that are currently heading for Iberia and southern France could also hit southern coastal areas. As it stands, rather brisk east winds could develop and with temperatures only 3-5 C the snow line would likely be not far above where a lot of people live at about 300m, so any slight changes would imply a wintry storm. This becomes almost a given for central and northern Britain given the depth of cold air back to the north and east.

    TODAY ... Partly cloudy to start the day and dry in most places until well into the afternoon when rain is likely to edge east from the Atlantic. Some other isolated showers may develop, and highs will be about 5-7 C except in Kerry and some other parts of west Munster where 8-10 C is possible.

    TONIGHT ... The rain will edge further east, becoming more sleety and mixing with snowfalls on higher terrain, with some accumulations of 5-10 cm developing especially above 250m. By morning, with lows of 1 or 2 C, rain may be mixing with wet snow in fairly low elevations. However, it will be just a rain event of 10-20 mm with some potential for minor flooding in west Munster, where lows of 4-6 C are likely.

    WEDNESDAY ... Further mixed showers with snow potential on higher terrain, mainly in southeast and Ulster, but trending to dry and colder later in the day as the band of sleety rain dissipates, highs about 3-7 C from east to west. Roads are likely to be very icy on medium to higher elevations all over the country except in the southwest where only higher elevations may see cold enough temperatures. Limited sunshine as cloud will be slow to break up after the rain dissipates.

    THURSDAY ... Clear intervals will develop early morning, as it becomes very cold especially in the north and east with lows -3 to -5 C. Some persistent freezing fog during the morning in central inland counties and very icy roads possible, but south and west could stay under low cloud and drizzle, lows of 2-4 C. The day will start bright in some eastern counties but the sun will fade behind increasing high cloud, while the lower cloud in the west pushes some further distance east with light rain to follow, turning to snow or sleet over northern hills. Highs of 2-6 C mildest near west coast. Light winds becoming SSE 20-40 km/hr late in the day.

    FRIDAY ... Early morning rain or drizzle near west coast, milder. Snow or sleet may develop for a time in the early morning further east then it should change to rain during the morning or mid-day. Accumulations 3-5 cm possible on hills. Morning lows near -1 C east, +5 C west and highs 7-10 C for most in developing southerly winds 30-50 km/hr veering to westerly, although Ulster more like 3-6 C in southeast winds becoming southwest later.

    SATURDAY ... Variable cloud, chilly with mixed wintry showers developing over northern regions, rain showers elsewhere with some hail and even thunder, strong winds may develop late in the day but details uncertain at this point ... lows near 2 C and highs near 7 C at best.

    SUNDAY ... A major storm system is currently indicated on several models and the details are uncertain, but the most likely outcome would be heavy rainfalls and strong east winds with temperatures in the 3-6 C range, also with heavy snow on higher summits. It would not take much to change this outlook to mixed precipitation at low elevations or even all snow in some northern or central districts. The track of the low is close to the south coast on a trajectory from WNW to ESE, which would only need to shift 100 miles south to bring in enough cold air for a snowstorm.

    MONDAY ... Whatever Sunday brings will be moving away with colder air arriving on northeast winds, wintry showers likely, highs near 4 C if not colder.

    FURTHER OUTLOOK ... The models are loaded with active weather from this weekend to as far as they run, and my research model says a major push of very cold air is increasingly likely. That all together could mean a snowfall potential before the month is over but one or two days could turn out quite mild with strong westerly winds too. It promises to be a real "battleground" period.

    Forecasts for Britain

    TODAY ... Some sunny intervals west, snow or sleet moving south and west from the North Sea inland into eastern England, some 5-15 cm snowfalls and locally bad road conditions ... highs 2-4 C but falling to -1 C in snow.

    WEDNESDAY ... Snow may become heavy in some eastern counties, mixed sleety showers in south with rain at times in Cornwall and south Wales, Devon. Snow amounts of 10-20 cm will be heaviest around Cambridge, Lincoln and Sheffield towards Newcastle. London may see a sleety mix and some minor disruptions but an interval of heavier snow cannot be ruled out. Highs about -1 C central to +4 C south. Scotland may see more sunshine than elsewhere with less windy conditions, after a severe frost to start the day.

    FURTHER OUTLOOK ... Cold and dry is most likely to prevail over weak and isolated outbreaks of snow or sleet, then a milder turn late in the week. Some lows around -7 C to -10 C during the cold spell Wed-Thurs. Slowly warming up to near normal by end of the week but with risk of further snow or sleet especially in central and eastern regions. A major rain or snow storm is likely over the weekend, with snow heavy in some central and northern regions on Sunday. Details will emerge closer to the event, but at the moment it looks like being 3-5 C in the south with strong SE winds and heavy rain, but -2 to +1 C further north with heavy sleet or snow. France will be hit by strong westerly gales during this storm (80-130 km/hr winds possible).

    North American forecasts

    Western regions of Canada are under a large blanket of cloud with a shallow layer of cold air trapped under mild Pacific air aloft, and this is promoting outbreaks of freezing drizzle or light drizzly snow. This trends to heavier snowfalls in the central prairies as a low forms there today and moves southeast into Minnesota tonight, dragging down another fresh batch of very cold arctic air behind it. The earlier cold wave is modifying today over the inland northeast and Great Lakes regions with highs near -5 C in wintry sunshine, trending to 5-7 C along the east coast. Cloud and rain are prevalent in the southeast states where it is slowly getting cooler after several very mild days. Highs will be 10-15 C except 20s in Florida. The southwest is gradually recovering from record cold under partly cloudy skies.

    My local weather on Monday was a drizzly foggy wet snowfall that left slush on roads and 1-2 cm on grassy surfaces. The high was about +1 C. It is now getting a bit milder and the sloppy mess outside is melting slowly.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Wednesday, 16 January, 2013

    Forecasts for Ireland


    Situation update: Thursday night's frontal event looks more likely to be all rain now but we will keep the chance of snow in the wording just in case the models do another course correction later. Then the front stalls a little further east on Saturday and tries to push back to the west about the same time as most models are showing deep low pressure running into the front from the Atlantic. Heavy rain could result on Sunday lasting into Monday and this could change over to heavy wet snow or even accumulating snow on hills as colder air feeds in from snow-covered (by then) Britain. There is a lot of uncertainty with this storm event and one of the major models (GFS) has a milder and weaker solution. Some solutions hint at snowstorm potential for eastern Ireland and most of Britain. We're in a close watch situation with this, given the fact that -13 C temperatures have already shown up over snow-covered Norfolk in eastern England, a good indication of the importance of snow cover since that's really the same air mass that managed to produce -4 to -6 C lows over bare ground recently.

    TODAY ... Further rain or mixed sleety showers with snow potential on higher terrain, mainly in southeast and in Ulster, but trending to dry and colder later in the day as the band of sleety rain dissipates, highs about 3-7 C from east to west. Roads are likely to become very icy by late afternoon and evening on medium to higher elevations all over the country except in the southwest where only higher elevations may see cold enough temperatures. Limited sunshine as cloud will be slow to break up after the rain dissipates but the sun could break through in west Munster at times this afternoon boosting temperatures there to 7-9 C. Rainfalls about 5-10 mm in some places.

    TONIGHT ... Only patchy and drizzly precipitation of a sleety nature is likely with many places dry under partly cloudy skies. Some ice and fog may develop and roads could be icy in many places away from the milder west and south. Lows -3 to +2 C but 2-5 C in parts of southwest.

    THURSDAY ... Some persistent freezing fog during the morning in central inland counties and very icy roads possible, but south and west will stay under low cloud and drizzle, lows of 2-4 C. East coast should escape most of the ice but won't be far above freezing until perhaps afternoon. The day will start bright in some eastern counties but the sun will fade behind increasing high cloud, while the lower cloud in the west pushes some further distance east with light rain to follow, turning to snow or sleet over northern hills but mainly above 350m so only an issue for people driving through some hilly areas. Highs of 3-8 C mildest near west coast. Light winds becoming SSE 30-50 km/hr late in the day and 40-80 km/hr near west coast, heavy rain at times by evening in west.

    FRIDAY ... Early morning rain or drizzle near west coast, milder. Snow or sleet may develop for a time in the early morning further east then it should change to rain during the morning or mid-day with potential for 10-20 mm rainfalls. Accumulations of snow possible on hills in Ulster. Morning lows near -1 C northeast, +2 east coast, +5 C west and highs 7-10 C for most in developing southerly winds 40-70 km/hr veering to westerly, although Ulster more like 3-6 C in southeast winds becoming southwest later.

    SATURDAY ... Variable cloud, chilly with mixed wintry showers developing over northern regions, rain showers elsewhere with some hail and even thunder, strong winds (south backing to east) may develop late in the day but details still uncertain at this point ... lows near 2 C and highs near 7 C at best.

    SUNDAY ... A major storm system is still indicated on several models (one delays the arrival until late Sunday into Monday) and the details are uncertain, but the most likely outcome would be heavy rainfalls and strong east winds with temperatures in the 3-6 C range, also with heavy snow on higher summits. It would not take much to change this outlook to mixed precipitation at low elevations or even all snow in some northern or central districts. The track of the low is close to the south coast on a trajectory from WNW to ESE, which would only need to shift 100 miles south to bring in enough cold air for a snowstorm. By Sunday night this may change to sleet with snow accumulating on higher terrain in strong NE winds 50-80 km/hr. There is perhaps a 20-30 per cent chance of this storm developing into a blizzard because on the track indicated and with sharp pressure falls, if air flowing in from snow-covered Britain is very cold, this could drop the temperatures over the Irish Sea to about +2 C which might change the event from the rain side of marginal to the snow side, and once snow begins further cooling takes place. We are in a "major storm watch" situation with this event. By the way, its effects on France could be severe with gale to storm force westerly winds hitting the southern half of the country and nearby northern coast of Spain.

    MONDAY ... The Sunday rain or snow event could continue some number of hours into Monday before pulling away to southeast, followed possibly by variable cloud and streamers of mixed wintry showers from a north or northeast trajectory. Highs about 3-5 C.

    FURTHER OUTLOOK ... Vast uncertainty on details, but a continued battleground situation should continue with any chance of a major westward advance of very cold air likely to be well into the last few days of January, but in the meantime, colder than average with about equal chances for rain, sleet or snow with the usual regional and elevation-based differences, through the period Tuesday to about Sunday 27th. Another major storm (assuming we see one on Sunday) could develop around Thursday or that following weekend also.

    Forecasts for Britain

    TODAY ... Outbreaks of heavy snow may become heavy in some eastern counties, mixed sleety showers in south with rain at times in Cornwall and south Wales, Devon. Snow amounts of 10-20 cm will be heaviest around Norfolk, Cambridge, Lincoln and Sheffield towards Newcastle and some parts of eastern Scotland. London may see a sleety mix and some minor disruptions but an interval of heavier snow cannot be ruled out. Highs about -1 C central to +4 C south. Temperatures much lower over snow cover (near -5 C). Scotland may see more sunshine than elsewhere with less windy conditions, after a severe frost to start the day. The west coast of Scotland will be showery and about 5-7 C.

    TONIGHT to SATURDAY ... This period will remain rather cold in all regions except immediate west coast and southwestern England which will be into the same somewhat milder air mass as Ireland, with temperatures near 5-7 C. In that air mass, some drizzly light rain at times but heavier on Friday in southwest Scotland and parts of Wales. Further east, outbreaks of snow at times, 3-5 cm daily accumulations but hit or miss over the eastern half of England and some parts of eastern Scotland. Highs near -2 C and lows -8 to -5 C for most but could fall to -15 C over snow cover where skies clear. (It is currently -13 C in northern Norfolk over fresh snow cover)

    FURTHER OUTLOOK ... A major rain or snow storm is likely over the weekend, with snow heavy in some central and northern regions on Sunday. Details will emerge closer to the event, but at the moment it looks like being 3-5 C in the south with strong SE winds and heavy rain, but -2 to +1 C further north with heavy sleet or snow. France will be hit by strong westerly gales during this storm (80-130 km/hr winds possible). This snowfall could reach 20-40 cm in some inland portions of England and Wales. The south coast is likely to remain more in sleet or rain but only a slight change would be needed to produce a more widespread blizzard-like storm that could also hit the northern parts of France and Belgium. Travel disruptions are likely Sunday to Tuesday.

    North American forecasts

    Much colder air is sweeping south behind a weak frontal system now situated in northern Ontario, Minnesota and South Dakota. Temperatures fall rapidly to near -20 C behind this front and tonight will fall to -35 C in some parts of the region. By tonight the front will be approaching a Toronto to Chicago line setting off major Great Lakes snow squalls in strong SW winds (Buffalo NY could see over a foot of snow). Tomorrow these squalls will come from a west to northwest direction giving many different places a period of 10-20 cm snow and locally 30-50 cm. A similar but stronger event is expected Sunday with 30-50 cm snow potential in the Great Lakes region. Meanwhile, the northeast states are in the previous modifying batch of cold air which is now around -2 C with light snow or freezing drizzle in places, trending to a cool rain in the southeast states near 10 C. That chilly air has pushed most of the way through Florida overnight but Miami will see thunderstorms and 24 C. Then in central parts of the U.S. it will be a cold, bright day but moderating somewhat in advance of the new arctic air mass to the north, highs 2-5 C. Snow tonight and severe cold by tomorrow for them. West coast and parts of Alberta, Montana are under much milder air masses from the Pacific now, and highs of 5-7 C can be expected at lower elevations with some mountain snow or freezing drizzle above 800m.

    My local weather on Tuesday was cloudy with a slight snow cover slowly melting (that disappeared closer to sea level) and highs about 5 C in light winds. Here's an oddity, record highs were set today in northern B.C. and southern Yukon, parts of Alaska (near 10 C) and there's a 932 mb low out in the Pacific southeast of far eastern Siberia, trying to push a strong arctic high of 1050 mbs in the western Canadian arctic back towards the north pole but not having much success. That low will apparently not hit land in any strength but will fill up gradually in the Gulf of Alaska.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Thursday, 17 January, 2013

    Forecasts for Ireland


    Situation update: Tonight, a frontal system will push slowly across the country bringing rain that could begin to turn to sleet or snow in parts of Ulster on Friday, while ending elsewhere. Colder air in place over Britain will push this front slowly back as low pressure forms near Donegal. By Saturday, colder air at or slightly below freezing will have seeped into most of the counties north of a Dublin to Galway line, then we face the uncertain prospect of stronger low pressure interacting with this front from its position somewhere off to the south or southwest of Kerry. This will tend to pull the frontal boundary slowly south and change any rain to sleet then snow from north to south. Possible outcomes vary from a rather messy mix to an all-out winter storm and the models are still struggling to resolve the Monday and Tuesday outcomes for the Atlantic storm. What seems most certain is that cold will deepen during the week until perhaps Thursday and that some severe winter conditions could develop in places.

    TODAY ... Some persistent mist or fog during the morning in central inland counties, northern and eastern counties, and slippery roads with poor visibility, drive with caution. South and west will stay under low cloud and drizzle, becoming a steady light rain later and edging further east during the afternoon. Highs about 5-7 C for most and 8-11 C west Munster.

    TONIGHT ... Rain may be turning to snow or sleet over northern hills but mainly above 350m so only an issue for people driving through some hilly areas until perhaps morning when a lower snow level could develop. Strong SE to S winds (50-80 km/hr) will develop in all regions veering to SW in west Munster, with 10-20 mm rainfalls. Lows about 5-7 C in south and west but closer to 3 C in east and 1 C in east Ulster.

    FRIDAY ... Rain ending during the morning in western counties, some isolated showers to follow in breezy to windy but mild conditions, highs 8-10 C. Rain tapering off to drizzle and fog in the east, highs near 6 C. Rain turning to sleet or snow in parts of Ulster with highs 2-4 C. In all regions winds will tend to decrease in the afternoon with calm conditions by evening and dense fog may become hazardous for travel.

    SATURDAY ... Variable cloud, chilly with mixed wintry showers developing over northern regions, rain showers elsewhere with some hail and even thunder, moderate winds (south backing to east) may develop late in the day but details still uncertain at this point ... morning lows near 2 C with some icy roads and colder readings in parts of Ulster (-2 C), and highs near 7 C at best in south, 3-5 C east and 1-3 C north. Ulster may begin to see accumulating snow by later in the day with 5-15 cm on higher terrain and 2-5 cm closer to sea level. Melting wet snow may begin over regions from inland Connacht to north Leinster, with some accumulations by the overnight hours into Sunday morning.

    Note for anyone with travel plans -- a winter storm could develop well to the south over Spain and affect conditions at Barcelona and nearby airports with snow possible above the immediate coastal plain. This is a separate system from the one to be discussed next.

    SUNDAY ... There is still uncertainty about developments off to the west but in any case the weather is likely to be cold and unsettled over Ireland with at least moderate east winds 30-50 km/hr and some mixed wintry showers that include some accumulating snow on hills, as temperatures struggle to get much above the morning lows of -1 to +1 C, possibly reaching 3-5 C in a few places. The south coast could be somewhat milder with 5-7 C and showers there might be mostly rain with some ice pellets. The range of possible outcomes especially for later Sunday into Monday morning does include heavier snow and stronger winds.

    MONDAY ... Moderate and possibly strong east winds, very cold, wintry showers and widespread snow possible, accumulations very uncertain due to questions about interaction with Atlantic low pressure, but 3-5 cm amounts seem likely and 5-15 cm possible, with an outside chance of heavier blizzard-like snowfalls especially on higher slopes in various regions (east-facing in the south, northeast-facing in the north). In general, this looks like a gradual descent into full winter conditions rather than something very sudden, with various districts or regions falling one at a time to the combination of colder temperatures and lower freezing levels.

    TUESDAY to FRIDAY ... This now appears to be a very cold interval with a high risk of snow accumulations at times, some periods of strong E to NE winds, and some freezing fog. Roads may be very icy throughout. Temperatures could be as low as -1 C daytime and -7 C overnight with local modification where winds cross warmer open water. Higher elevations could see a range from -3 to -9 C. This wintry spell is about 70% likely (in my view) and there is still some chance of a milder outcome than this. There is also a slight chance of a more severe blizzard-like outcome.

    FURTHER OUTCOME ... With this much uncertainty, the only thing we can add is that some models are signalling a slightly milder turn in the last week of January but with more severe cold building up in Scandinavia getting ready possibly for a more severe assault on Britain and Ireland.

    Forecasts for Britain

    TODAY ... Cloudy, cold, some outbreaks of snow or (in southwest only) rain, highs about 5 C in southwest and western Scotland, 2-4 C coasts of Wales and northwest England, -3 to -1 C elsewhere. Some freezing fog and icy roads especially where snow has already fallen.

    TONIGHT ... Rain in west and southwest, foggy, windy, mixing with snow by morning, snow developing further east towards morning, clear intervals and very cold in eastern England, ice fog in places. Lows in a large range, from about +5 C in Cornwall and near Cardigan Bay to zero in the west Midlands and south central England to -10 C over snow cover in eastern England and generally from +3 C in western Scotland to -7 C inland and eastern regions.

    FRIDAY ... Widespread snowfalls of 5-15 cm with local 20 cm accumulations, rain turning to snow in Wales and northwest England, western Scotland, but rain continuing in southwest England where highs 5-7 C. Otherwise temperatures will fall steadily in west to near -3 C and stay very cold in the east near -6 C.

    WEEKEND OUTLOOK ... Further snow, risk of stormy mixed wintry conditions in southwest by Sunday, locally heavy snow streamers in eastern England, but some dry areas too, ice fog and lows around -10 C in rural areas, highs around -4 C, trending to near 3 C in south coast and 5 C in southwest.

    FURTHER OUTLOOK ... Possible severe winter storm conditions at times during the week, very cold, highs only near -4 C and lows around -10 C. Travel in most of the U.K. may become very difficult especially by road next week.

    North American forecasts

    Windy and turning much colder across the Great Lakes, Midwest and central plains states as a strong cold front moves in from northwest. Intervals of snow, temperatures dropping from 0 C to -10 C. Cloudy and misty with drizzle or wet snow near east coast, highs 2-4 C. Southeast somewhat milder with rain and fog, highs 11-15 C. A more severe cold wave will develop over the weekend when a low now forming in Alberta reaches Ontario in 2-3 days. For now, this low is bringing freezing rain and snow to northern parts of Alberta and central SK moving to southern Manitoba by tonight. It is fairly mild in a weak chinook pattern in southern Alberta (6-9 C) and some western valleys are under a low cloud inversion with -5 C air trapped in valleys while higher up it is sunny and 3 C. Partly cloudy and milder on the west coast, 7-10 C.

    My local weather on Wednesday was cloudy and about 6 C with some late afternoon sunshine. It is a bit foggy out under otherwise clear skies at almost midnight and -1 C.

    Will be sure to update this forecast for Ireland especially if the 12z model runs have different themes. In the meantime, consult the other thousand weather watchers on the forum for a never-ending analysis of events.


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  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Friday, 18 January, 2013

    Forecasts for Ireland


    Situation update: The front that swept through Ireland overnight has stalled and colder air is mixing into the moisture, changing rain to sleet. Some accumulating snow will begin later this morning over higher parts of Ulster. Gradually, from this afternoon to mid-day Saturday, low pressure will develop over Ireland organizing this mixed bag of precipitation while temperatures continue to fall slowly everywhere, and this will continue to shift the balance between rain and snow both in terms of elevation and from north to south. By Saturday night it will probably become cold enough to snow just about anywhere but moisture may then begin to break into less organized patterns, so snowfall later in the weekend will be hit or miss. The east coast will be favoured because of sea effect but as the Irish Sea is quite warm compared to the air mass, sea level areas in Dublin and Wicklow could see sleety or mixed showers. The potential for heavy snow in all of this remains highest, I believe, in two places, hills of Donegal and Derry and some other parts of the north, and from about 150m to near summit levels on the east side of the Dublin and Wicklow Mountains. Eventually about half to two-thirds of Ireland's land mass should be covered in at least 2-4 cm of snow and a few places will see more, perhaps 15-25 cm on higher ground in some isolated instances. This period will bring widespread mixed sleety precipitation before snow and coatings of ice or half-frozen slush will make walking and driving difficult at best. Plan for delays and perhaps one or two closed roads in hilly areas.


    TODAY ... Some isolated showers with hail and perhaps thunder in western counties especially Kerry and Cork with a few sunny intervals and moderate southeast winds, highs 6-9 C. Rain tapering off to drizzle and fog in the east and parts of the northwest, highs near 6 C. Foggy over hills. Rain turning to sleet or snow in parts of Ulster with highs 2-4 C. In all regions winds will tend to decrease from morning levels (SE 40-70 km/hr to 20-40 km/hr by afternoon) with calm conditions by evening so that dense fog may become hazardous for travel. Rain will mix with snow or sleet over much of Ulster and parts of north Leinster, inland north Connacht, and snow accumulations may begin on higher terrain.

    TONIGHT ... Snow becoming more widespread north of a Dublin to Galway line and sleet further south could be associated with hill snow above 250m at first, a very cold feeling night in raw, sleety or foggy conditions, some icy roads developing. Falls of 3-7 cm snow can be expected on a hit and miss basis across the northern half of the country. Lows -2 to +2 C but 2-5 C southwest.

    SATURDAY ... Variable cloud, chilly with mixed wintry showers including heavy snow showers over northern and central regions, rain showers south and east coast near sea level, with some hail and even thunder, becoming somewhat windy again (ESE 30-50 km/hr) after low pressure drifts south, highs 3-5 C east and 1-3 C north. Ulster may see 5-15 cm snow on higher terrain and 2-5 cm closer to sea level. Melting wet snow may begin over regions from inland Connacht to north Leinster, with some accumulations of 3-7 cm by the afternoon and overnight hours into Sunday morning. Very icy roads can be expected especially in central inland counties.

    Note for anyone with travel plans -- a winter storm could develop well to the south over Spain and affect conditions at Barcelona and nearby airports with snow possible above the immediate coastal plain. This is a separate system from the one to be discussed next.

    SUNDAY ... Rather windy and very cold with local snow streamers coming inland from Irish Sea in E to SE winds and from the Atlantic in parts of Donegal and Mayo in NE winds of 40-60 km/hr. Some wintry sunshine at times further west but isolated wintry showers could develop in various places, and we are still on a close watch for any more organized snowfalls that are now likely to arrive Sunday night. Highs only 2-5 C for most and could stay near zero where snow cover has developed.

    SUNDAY NIGHT into MONDAY ... Moderate and possibly strong east winds (40-70 km/hr), very cold, wintry showers and widespread snow possible, accumulations of 3-7 cm amounts seem likely and 5-15 cm possible, in perhaps half to two-thirds of regions, with an outside chance of heavier blizzard-like snowfalls especially on higher slopes in various regions (east-facing in the south, northeast-facing in the north). Overnight lows -4 to -1 C and highs -2 to +4 C. Snowfall risk areas will become clearer as we get closer to the time, but west Munster cannot be ruled out given the set-up.

    TUESDAY to FRIDAY ... This now appears to be a very cold interval with a high risk of snow accumulations at times, some periods of strong E to NE winds, and some freezing fog. Roads may be very icy throughout. Temperatures could be as low as -1 C daytime and -7 C overnight with local modification where winds cross warmer open water. Higher elevations could see a range from -3 to -9 C. This wintry spell is about 70% likely (in my view) and there is still some chance of a milder outcome than this. Some recent guidance suggests a milder turn around Thursday after another mixed precipitation event mid-week with a slow-moving warm front. There is also a slight chance of a more severe blizzard-like outcome during the period. Model guidance is assessed as only marginally reliable beyond four days at present.

    FURTHER OUTCOME ... With this much uncertainty, the only thing we can add is that some models are signalling a slightly milder turn in the last week of January but with more severe cold building up in Scandinavia getting ready possibly for a more severe assault on Britain and Ireland.

    Forecasts for Britain

    TODAY ... Widespread snowfalls of 5-15 cm with local 20 cm accumulations, rain turning to snow in Wales and northwest England, western Scotland, but rain continuing in southwest England near sea level only where highs 5-7 C. Otherwise temperatures will fall steadily in west to near -3 C and stay very cold in the east near -6 C. Some road closures are likely, airport delays are very likely and flights may be cancelled in some cases. Snow is also spreading across France from west to east.

    TONIGHT ... Further snow at times, 2-4 cm on average, very cold, lows -7 to -3 C for most, about zero to +2 C south coast and parts of northern Scotland.

    WEEKEND OUTLOOK ... Further snow, risk of stormy mixed wintry conditions in southwest by Sunday, locally heavy snow streamers in eastern England, but some dry areas too, ice fog and lows around -10 C in rural areas, highs around -4 C, trending to near 3 C in south coast and 5 C in southwest. Continued road problems and some airport delays likely.

    FURTHER OUTLOOK ... Possible severe winter storm conditions at times during the week, very cold, highs only near -4 C and lows around -10 C. Travel in most of the U.K. may remain very difficult especially by road next week.

    North American forecasts

    Great Lakes and Midwest will slowly warm up ahead of a stronger cold front today and Saturday, temperatures will be near freezing today and near +3 Saturday with wet snow or drizzle tonight and tomorrow, then widespread snow squalls, blowing snow, some accumulations to 30 cms and much colder through Sunday into Monday. Temperatures falling to -20 C by Monday.

    Northeast states will become milder also until Sunday mid-day, some rain will spread in from southwest ahead of a sharp cold front with thunder-snow possible Sunday. Highs today and tomorrow about 4-7 C then falling to -10 C late Sunday and Monday.

    Northern and central plains states will be very windy and much milder for today, 10-15 C, then very strong northerly winds tonight, temperatures falling rapidly all day Saturday in blowing snow, to -25 C by Sunday morning.

    Canadian prairies will have an interval of snow today with 3-7 cm, mild in southern Alberta, then much colder tonight falling to -30 C in places by Saturday and limited recovery all weekend under wintry sunshine and clear nights. Some lows to -40 C in Manitoba and northern Ontario by Sunday.

    West coast will be mild and dry on the warm side of a very strong upper level ridge, highs 5-8 C with hazy sunshine but some valleys will have persistent fog and low cloud.

    My local weather on Thursday was sunny with a high near 6 C. The evening was clear with a nearly half moon and a good view of Jupiter which the Moon will pass on Monday night (22:03z).


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    UPDATE _ Friday 18 January 2013 _ 1800h
    _______________________________________

    ALERT for accumulating snow overnight for parts of inland north Leinster, higher slopes of east Wicklow and Dublin, 3-7 cm with 10-20 cm locally in Wicklow. Continued 3-7 cm accumulations in higher parts of Ulster.

    ALERT for onset of patchy accumulating snow all other counties north of a line from Wicklow (south) to Clare (central) in the period 0700h Saturday to 0700h Sunday, 2-5 cm can be expected to cover about half to two-thirds of this zone due to outbreaks of snow showers drifting around a weak low that is pushing west into the Atlantic. This snow may start as sleet but as upper level temperatures chill to -7 C the snow quality should improve. Some higher areas could see 10 cm. Also the aforementioned higher portions of Dublin and Wicklow will continue to see heavier snow in this period.

    ADVANCE ALERT for patchy accumulating snow in west Munster late Sunday into Monday, 3-7 cm potential, mainly above 150m in Kerry but closer to sea level in Cork and west Limerick. During this period further snow may fall in zones already outlined but not necessarily all of them, from streamers coming inland from the Irish Sea in moderate east winds. Local accumulations in this period of 2-10 cm are possible.

    Waterford and lower parts of Wexford could possibly see a bit of snow in this period and sleety accumulations on grassy surfaces but the least likely place for snow in the entire scenario would be around Rosslare to coastal Waterford (due to insufficient cooling of entire atmospheric profile). This could change if stronger low pressure develops in the trough depicted on models for Monday-Tuesday. Anything more organized in that zone around Cornwall to south Wales could produce heavier snowfall amounts in many parts of Ireland and we are on a close watch basis as model reliability at present is lower than usual.

    Further updates as required.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Saturday, 19 January, 2013

    Forecasts for Ireland


    ALERT for widespread outbreaks of sleet and snow, with some accumulations as explained in forecasts, now to end of Tuesday with increasing risk towards south and west over time. ALERT for widespread icy roads next three or four days, drive with caution and expect delays on some routes.

    TODAY ... Mostly cloudy, cold with mixed wintry showers including heavy snow showers over northern and central regions, rain showers southeast coast near sea level, with some hail and even thunder, becoming somewhat windy again (ESE 30-50 km/hr) morning temperatures 2-4 C east and 0-3 C north may actually fall by afternoon to the range of -2 to +1. Some parts of inland west, north and east may see 5-15 cm further snow on higher terrain and 2-5 cm closer to sea level. Melting wet snow may begin over regions from south Connacht to north Leinster, with some accumulations of 3-7 cm by the afternoon and overnight hours into Sunday morning. Very icy roads can be expected especially in central inland counties. Some outbreaks of moderate rain will continue over parts of Wexford and Waterford but this could also turn to sleet. Heavy snow may develop on east slopes of Dublin and Wicklow Mountains. Widespread slippery and later icy roads, but highly variable conditions, drive with caution due to both hazards and the variable conditions along the way.

    Note for anyone with travel plans -- a winter storm has developed well to the south over Spain and this will affect conditions at Barcelona and nearby airports with snow possible above the immediate coastal plain, thunder and hail showers near the coast and locally gusty winds.

    TONIGHT ... Very cold with a cutting east wind of 30-50 km/hr adding chill to temperatures in the -6 to -2 C range, some ice fog developing inland, further scattered snow showers over much of the country, and streamers possible near Irish Sea. Even so, about half to two-thirds of the country may remain dry but snow accumulations in places might be 5-15 cm.

    SUNDAY ... Rather windy and very cold with local snow streamers coming inland from Irish Sea in E to SE winds and from the Atlantic in parts of Donegal and Mayo in NE winds of 40-60 km/hr. Some wintry sunshine at times further west but isolated wintry showers could develop in various places, and we are still on a close watch for any more organized snowfalls that are now likely to arrive Sunday night. Highs only 2-5 C for most and could stay near zero where snow cover has developed. Some snow accumulations of 5-15 cm.

    SUNDAY NIGHT into MONDAY ... Moderate and possibly strong east winds (40-70 km/hr), very cold, wintry showers and widespread snow possible, accumulations of 3-7 cm amounts seem likely and 5-15 cm possible, in perhaps half to two-thirds of regions, with an outside chance of heavier blizzard-like snowfalls especially on higher slopes in various regions (east-facing in the south, northeast-facing in the north). Overnight lows -4 to -1 C and highs -2 to +4 C. Snowfall risk areas will become clearer as we get closer to the time, but west Munster cannot be ruled out given the set-up.

    TUESDAY ... Continued very cold interval with a risk of snow showers and further slight accumulations, moderate E-NE winds, and some freezing fog. Roads may be very icy throughout. Temperatures could be as low as -1 C daytime and -7 C overnight with local modification where winds cross warmer open water. Higher elevations could see a range from -3 to -9 C.

    WEDNESDAY ... Somewhat milder in cloudy, drizzly conditions west, freezing drizzle or snow east, winds turning more to SSE 30-50 km/hr. Lows -3 to +1 C and highs 3-7 C mildest near west coast.

    OUTLOOK ... A further wintry period could redevelop but will base forecast on model majority consensus (by no means unanimous) that milder air will slowly return late Wednesday into Thursday. Periods of rain can be expected to thaw any frozen ground and lying snow later in the week, faster in Atlantic counties. From Friday to about Monday, a very unsettled and possibly stormy interval seems likely with strong winds and occasional heavy showers or periods of rain, highs 6-9 C. The less likely outcome would be further mixed or wintry showers through this whole period, highs 2-4 C. A somewhat milder spell with strong winds could come to a rather abrupt end with another surge of cold air near the middle to end of the following week.

    Forecasts for Britain

    TODAY ... Further snow although generally light, except for locally heavy snow streamers in eastern England, but some dry areas too, highs about -2 to +2 C ... mixed sleety showers in southwest England and parts of northern Scotland.

    TONIGHT ... Very cold with ice fog and lows around -10 C in rural areas, -4 in larger cities and near south coast.

    SUNDAY ... Cloudy, outbreaks of sleet or snow, cold ... highs around -4 C, trending to near 3 C in south coast and 5 C in southwest. Continued road problems and some airport delays likely.

    FURTHER OUTLOOK ... Possible severe winter storm conditions at times during the week, very cold, highs only near -4 C and lows around -10 C. Travel in most of the U.K. may remain very difficult especially by road next week. Milder air that could move into Ireland late in the week will only make easy progress into western Britain and could fail to reach some eastern and southeastern counties of England. A major storm with mixed precipitation types could develop around the following weekend.

    North American forecasts

    Great Lakes and Midwest will slowly warm up ahead of a strong cold front arriving tonight. Highs will be near +3 today with wet snow or drizzle, then a flash freeze late overnight followed by heavy snow and snow squalls, blowing snow, some accumulations to 30 cms and much colder through Sunday into Monday. Temperatures falling to -20 C by Monday. Winds SW 40-70 km/hr increasing to WNW 50-90 km/hr late tonight and Sunday.

    Northeast states will become milder also until Sunday mid-day, some rain will spread in from southwest ahead of the same sharp cold front with thunder-snow possible Sunday in rapidly falling temperatures. Highs today and tomorrow about 4-7 C then falling to -10 C late Sunday and Monday.

    Northern and central plains states will be very windy and mild for a few more hours, with temperatures near 5 C, then very strong northerly winds will arrive by morning (southern MN-western IA) to mid-day further southeast towards Chicago, temperatures falling rapidly all day in blowing snow (a "ground blizzard" warning has been posted by the NWS), to about -20 C or lower by Sunday morning. Sunny and very cold with blowing snow on Sunday.

    Canadian prairies will have an interval of snow this morning before sunrise with 3-7 cm, mild conditions will abruptly end in southern Alberta, then much colder in all regions tonight falling to -30 C in eastern regions by Saturday night and limited recovery on Sunday under wintry sunshine and clear nights. Some lows to -40 C in Manitoba and northern Ontario by Sunday. Alberta will fall to a more moderate -15 to -20 C with light east winds undercutting a frontal band of cloud and light snow.

    The west coast will be mild and dry on the warm side of a very strong upper level ridge, highs 5-8 C with hazy sunshine but some valleys will have persistent fog and low cloud. Southwest states will be warmer than recent days and sunny in most places, highs about 20 C in valleys and 10 C on plateaux. Cold nights over snow cover in higher areas.

    My local weather on Friday was partly cloudy and hazy with a high near 7 C.

    Watch for updates and enjoy the discussions and banter on the forum threads, and remember, this pattern is both difficult and bound to be disorganized, weather conditions are likely to vary from place to place -- radar is your best friend in this kind of pattern.

    :)


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Sunday, 20 January, 2013

    Forecasts for Ireland


    ALERT for further outbreaks of sleet and snow, with some accumulations expected in north and higher parts of east today, then inland southwest to south central tonight, and across parts of the south on Monday and Tuesday. ALERT for widespread icy roads next three or four days, drive with caution and expect delays on some routes.

    Note for anyone with travel plans -- a winter storm has developed well to the south over France and Spain and this will affect conditions at Barcelona and various French airports including Paris (10-20 cm), with heavy snow possible and in Spain, above 150m, with thunder and hail showers near the coast and locally gusty winds. London may also see further snow later today (3-7 cm).

    TODAY ... Rather windy and very cold with local snow streamers (mixed with sleet in coastal districts) coming inland from Irish Sea in E to SE winds of 30-50 km/hr. Snowfalls of 5-10 cm possible well inland into south Ulster and north Leinster, as well as on higher parts of Dublin and Wicklow. Some wintry sunshine at times further west but isolated wintry showers could develop in various places, and sleet may begin by evening in Kerry. Also some cold rain showers here and there across the south, turning to sleet above 200m. Highs only 2-5 C for most and could stay near zero where snow cover has developed.

    TONIGHT ... Cloudy and cold, some scattered sleet or snow showers in various places but a more organized band of rain turning to sleet inland will hit the southwest during the evening, and sleet will then turn to snow inland and mainly above 100m (200m Kerry) but some heavy accumulations (5-8 cm) are possible especially in higher parts of Cork, east Kerry and west Limerick. Lows near zero C in the south and west, to -3 C in central and east coast districts and -5 C locally in north where skies clear briefly.

    MONDAY ... Moderate and possibly strong east winds (40-70 km/hr), continued cold, wintry showers and widespread snow possible, accumulations of 3-7 cm amounts seem likely and 5-15 cm possible, in perhaps half to two-thirds of counties south of Mayo to Meath, and with some dry areas a bit further north, then further snow in Ulster arriving from a separate system moving in from Britain Highs -2 to +4 C. Watch for updates as we track this system later today.

    TUESDAY ... Continued very cold interval with a risk of snow showers and further slight accumulations, moderate E-NE winds, and some freezing fog. Roads may be very icy throughout. Temperatures could be as low as -1 C daytime to about +3 C, and between -2 and -6 C overnight with local modification where winds cross warmer open water.

    WEDNESDAY ... Somewhat milder in cloudy, drizzly conditions west, freezing drizzle or snow east, winds turning more to SSE 30-50 km/hr. Lows -3 to +1 C and highs 3-7 C mildest near west coast.

    THURSDAY ... Cloudy, a bit milder again, sleet or rain, southeast to south winds 40-70 km/hr and highs near 5 or 6 C.

    FRIDAY to SUNDAY ... Risk of very windy weather and squally showers, gales from a SW to WNW direction at times, highs about 7 C.

    FURTHER OUTLOOK ... Very uncertain at this point, but one or two more relatively mild days could follow the windy interval then a gradual turn to colder weather might be next up around the first of February.

    Forecasts for Britain

    TODAY ... Cloudy, outbreaks of sleet or snow, mostly in southeast England inland with sleet or cold rain near coast, highs around -2 C, trending to 3 C south coast and 5 C in southwest. Continued road problems and some airport delays likely especially for London region. Snowfalls 3-7 cm.

    TONIGHT ... Cloudy, sleet or snow moving north then northwest through much of England and north Wales, lows -2 to 0 C. Snowfalls 5-10 cm. This is the snow likely to reach Ulster on Monday.

    FURTHER OUTLOOK ... Possible severe winter storm conditions at times during the week, very cold, highs only near -2 C and lows around -7 C inland, somewhat milder near coasts. Travel in most of the U.K. may remain very difficult especially by road next week. Milder air that could move into Ireland late in the week will only make easy progress into western Britain and could fail to reach some eastern and southeastern counties of England. A major storm with mixed precipitation types could develop around the following weekend.

    North American forecasts

    Great Lakes and Midwest will have very strong westerly winds, locally heavy snow squalls (20-40 cm) and a flash freeze already starting west of Detroit and soon to reach Toronto and Buffalo NY. Winds WSW 60-110 km/hr with some wind damage possible, decreasing tonight to 40-70 km/hr. Road closures are likely in "snow belt" areas as mega-squalls develop, with some thunder-snow.Temperatures falling all day to about -10 C mid-day then further to -15 to -20 C by Monday. Several more very cold and windy days with local squalls can be expected.

    Northeast states (east of the Appalachians) will remain mild until Sunday mid-day, some rain or thundershowers will spread in from southwest ahead of the same sharp cold front with thunder-snow possible Sunday afternoon in rapidly falling temperatures. Today's football game near Boston should be interesting for the weather alone, as gale force westerlies arrive on the east coast, with high temperatures of about 4-7 C falling to -10 C late this evening and -15 C by Monday morning. Not much snow east of the mountains which will get perhaps 2-4 cm on average although some heavier falls on west-facing slopes but mountains of New England could see 10-20 cm and Mount Washington NH could see wind gusts of 180 km/hr or stronger.

    Northern and central plains states will be very windy and cold, with temperatures falling rapidly all day in blowing snow (a "ground blizzard" warning has been posted by the NWS), sunshine won't do much to warm temperatures above -15 C with wind chills near -35 C. Clear and very cold to start tonight with snow arriving later from northwest, 3-7 cm possible. Temperatures steady near -17 C.

    Canadian prairies will be very cold and mostly sunny except for cloud and light snow near Calgary, elsewhere wintry sunshine and clear tonight, very cold. Some lows to -40 C in Manitoba, Saskatchewan and northwestern Ontario by tonight. Alberta will fall to a more moderate -15 to -20 C with light east winds undercutting a frontal band of cloud and light snow.

    The west coast will continue mild and dry on the warm side of a very strong upper level ridge, highs 5-8 C with hazy sunshine but some valleys will have persistent fog and low cloud. Southwest states will continue warm with highs about 22 C in valleys and 13 C on plateaux. Cold nights over snow cover in higher areas.

    My local weather on Saturday was foggy for part of the morning, then almost warm and sunny for a few hours, then back to light fog by evening, in an inversion that partly broke down to allow a high of 9 C.

    plan ahead astronomy note: The waxing half-moon will move just below the planet Jupiter as seen from the northern hemisphere (and briefly behind the Moon as seen from the South Pacific) tonight around 0300h Tuesday 22nd.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Monday, 21 January, 2013

    Forecasts for Ireland


    ALERT for sleet and snow, with some accumulations expected in three separate zones, one being mainly in Ulster (5-10 cm possible), another east coast mainly above 150m but possibly mixing down lower, 3-7 cm, and then a third zone across Munster from west to east, mainly this morning and inland above 100m where a further 5-10 cm could accumulate. All of these will mix with sleet and coastal rain and accumulations may be patchy. ADVANCE ALERT for possible reload of southern snow tonight and Tuesday, possibly extending some distance into central counties. ALERT for widespread icy roads next three or four days, drive with caution and expect delays on some routes.

    Astronomy note: The waxing half-moon will move just below the planet Jupiter as seen from the northern hemisphere (and briefly behind the Moon as seen from the South Pacific) tonight around 0300h Tuesday 22nd

    MONDAY ... Moderate east winds (30-50 km/hr), continued cold, wintry showers and widespread outbreaks of snow possible, accumulations of 3-7 cm amounts seem likely and 5-15 cm possible, across Munster from west to east, also in east coast counties mainly above 150m and across Ulster from southeast to northwest during the day. Some mainly dry areas will be found between these bands especially in Connacht but isolated sleet or snow showers could develop anywhere. Highs -1 to +4 C. The snow and sleet in parts of Munster should produce accumulating snows inland above 100m for most of the morning but could turn to sleet or rain closer to the sea and also increasingly as the system moves further east. The east coast snow showers could become heavy on higher terrain in Dublin and Wicklow, 10-20 cm local accumulations are possible above 250m.

    TONIGHT ... Cloudy with a few clear intervals, very cold, icy roads and patchy freezing fog, as sleet or snow tend to die out except possibly in west Munster where a second system is due this evening to midnight. This may prove to be rather disorganized but has potential to drop 5-8 cm of snow especially where snow fell today (colder surface creating better potential). Other snow areas are likely to peter out. Lows -4 to -1 C for most and about +1 C in milder coastal areas.

    TUESDAY ... Continued very cold interval with a risk of snow showers and further slight or even moderate accumulations to 7 cm in parts of the south, central and east, isolated 2-4 cm in Ulster, moderate E-NE winds 30-50 km/hr although SSE for a time near Atlantic coast, and some freezing fog. Roads may be very icy throughout. Temperatures could be as low as -1 C daytime to about +3 C. Keeping a close eye on the weak system approaching from a WNW direction for Tuesday morning.

    WEDNESDAY ... Somewhat milder in west in cloudy, drizzly conditions, freezing drizzle or snow possible near east coast where it stays quite cold, winds turning more to SE 30-50 km/hr. Lows -5 to +1 C and highs 1-7 C mildest near west coast. Some persistent freezing fog may develop in east-central counties over any snow cover.

    THURSDAY ... Cloudy, a bit milder again, sleet or rain, although may remain wet snow mixing with sleet in parts of Leinster, with southeast to south winds 40-70 km/hr and highs near 5 or 6 C in most regions, possibly staying cold (1-3 C) east.

    FRIDAY to SUNDAY ... Risk of very windy weather and squally showers, gales from a SW to WNW direction at times, highs about 7 C.

    FURTHER OUTLOOK ... Very uncertain at this point, but one or two more relatively mild days could follow the windy interval then a gradual turn to colder weather might be next up around the first of February. Model guidance more than seven days into the future has been very weak for many days now and I am finding my research model input more useful past that time frame, and here I find a strong cold signal for February. One or two very mild days at the end of January would not surprise, but eventually there is very strong high pressure waiting around on the Siberian side of the north pole drifting erratically northwest and I get the feeling that may start to link to continental high pressure in central Siberia with the whole complex trying to move west. This could feed much colder air than we've seen so far in this rather anemic cold spell. (less anemic in Britain, however)

    Forecasts for Britain

    TODAY ... Snow moving northwest and out into Irish Sea this morning, towards Ulster ... leftover patchy wet snow or freezing drizzle, low cloud, freezing fog may form and it will stay quite cold in raw east winds of about 30-50 km/hr. Highs -2 to +2 C.

    TONIGHT ... Little change, lows -5 to -3 C.

    TUESDAY ... Cloudy and cold, possible outbreaks of snow or sleet southwest into Wales, also near east coast. Highs -2 to +2 C.

    FURTHER OUTLOOK ... Very cold especially in the southeastern counties of England, minor outbreaks of snow or sleet at times, very slow warming trend affecting mainly western districts and Scotland in a weak southwest flow that may become much stronger by the weekend, as a major storm with mixed precipitation types could develop then, bringing temperatures gradually above freezing and towards 6-8 C eventually.

    North American forecasts

    Great Lakes and Midwest will have very cold weather with further outbreaks of light to moderate snow, mainly lake effect, but a general 1-3 cm could fall from a weak embedded system with 5-15 cm in snow belts. Highs near -7 C in south to -15 C north. Turning even colder on Tuesday with daytime readings -10 to -20 C, nights near -25 C. Light snow at times through midweek and a major snowfall event later in the week.

    Northeast states (east of the Appalachians) will be windy and cold with some sunshine and passing flurries, winds picking up in the afternoon to NNW 30-60 km/hr and highs around -2 C or colder inland.

    Northern and central plains states will be less windy but very cold, with temperatures near record low values of -25 C night and -15 C daytime, trending to about -7 C in Kansas. Snow may develop in places tonight and tomorrow.

    Canadian prairies will be very cold and mostly sunny except for cloud near the foothills in Alberta, elsewhere wintry sunshine and clear tonight, very cold. Some lows to -40 C in Manitoba, Saskatchewan and northwestern Ontario tonight and tomorrow night. Daytime highs -20 to -28 C in most places.

    The west coast will continue rather mild with extensive fog and highs 5-8 C. where low cloud or fog dissipate, otherwise near 2 C. The southwest states are generally warm now with highs in the 20s.

    My local weather on Sunday was very foggy for part of the morning, then a bit warmer and sunny for a few hours, then back to dense fog by evening, in an inversion that partly broke down again to allow a high of 7 C. There were strange optical effects around the city from reflected light off high rise towers, due to drifting fog banks interacting with the bright sunshine.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Tuesday, 22 January, 2013

    Forecasts for Ireland


    ALERT for sleet and snow, with some accumulations expected in western counties and close to the east coast. Amounts may be rather slight but potential is there for 5-7 cm in a few locations, watch for updates. ALERT for widespread icy roads next two or three days, drive with caution and expect delays on a few routes.

    TODAY ... This is probably as cold as the current cold spell will get, although a few places could be just as cold tomorrow morning. Temperatures later today will recover only slightly to highs of -1 to +2 C in most cases, and outbreaks of mostly light snow will continue near coasts, slight amounts for most but 5-7 cm potential under heavier bands. Moderate E-NE winds 30-50 km/hr although SSE for a time near Atlantic coast, and some freezing fog. Roads may be very icy throughout, although conditions are likely to be quite variable which is a hazard in itself. Skies will be mostly cloudy with some slight breaks here and there, but sunshine will be rare.

    TONIGHT ... Another cloudy and cold night with light snow in a few places, perhaps somewhat heavier inland south as another weak system develops and slides down the front west of Kerry towards France. Lows about -3 C or perhaps a bit lower in some eastern inland locations.

    WEDNESDAY ... Somewhat milder in west in cloudy, drizzly conditions, freezing drizzle or snow possible near east coast where it stays quite cold, winds turning more to SE 30-50 km/hr. Lows -5 to +1 C and highs 1-7 C mildest near west coast. Some persistent freezing fog may develop in east-central counties over any snow cover.

    THURSDAY ... Cloudy, a bit milder again, sleet or rain, although may remain wet snow mixing with sleet in parts of Leinster, with southeast to south winds 40-70 km/hr and highs near 5 or 6 C in most regions, possibly staying cold (1-3 C) east. Precipitation amounts fairly light with this weak warm front but could become a bit heavier in the northwest by evening (sleet to rain, 10 mm potential).

    FRIDAY ... Rain and fog, milder, moderate south winds veering westerly late in the day, kiws 2-4 C and highs 7-10 C west, 3-7 C east. This rain could begin as sleet on higher ground in the east. Winds S to WSW 40-60 km/hr.

    SATURDAY ... Variable cloud, breezy, cooler again but only slight frost, lows near -1 C and highs near 7 C in westerly winds 30-50 km/hr., squally showers at times but also some welcome sunshine.

    SUNDAY ... Risk of very windy weather and squally showers, gales from a SW to WNW direction 50-90 km/hr (possibly stronger in north), highs about 7 C.

    OUTLOOK ... Next week may turn very mild again for a few days, then we will perhaps be on another cold spell watch, no strong indication of how quickly this may arrive as it would probably come from a source currently around the north pole where very high pressure is eddying around just on the Siberian side of the pole (I had to laugh at the weather map that had a 1053 mb low between two 1058 mb highs up there).


    Forecasts for Britain

    TODAY ... Mostly cloudy, cold with outbreaks of sleet or snow mainly across coastal regions west and northeast. Highs about -2 to +2 C. Some patchy ice fog. Winds SE 30-50 km/hr with some stronger gusts near exposed coasts.

    TONIGHT ... Further light snow in some southern districts, partly cloudy and very cold further north, lows -7 to -4 C.

    FURTHER OUTLOOK ... Very cold especially in the southeastern counties of England, minor outbreaks of snow or sleet at times, very slow warming trend affecting mainly western districts and Scotland in a weak southwest flow that may become much stronger by the weekend, as a major storm with mixed precipitation types could develop then, bringing temperatures gradually above freezing and towards 6-8 C eventually.


    North American forecasts

    Great Lakes and Midwest will become even colder today as squalls hit a few locations but most places get frigid cloudy to partly cloudy conditions with daytime readings -10 to -20 C, then around -15 to -22 C tonight with light snow developing across the eastern Lakes, flurries further west. Some local snowfalls of 5-15 cm although most places dry. Continued very cold for several more days with risk of a snowstorm 10-20 cm on Thursday west into Friday east.

    Northeast states (east of the Appalachians) will be windy and cold with some sunshine and a few passing flurries, winds NW 30-60 km/hr and highs -4 around DC to -10 C around Boston. Even colder on Wednesday with more flurries at times (Boston could be close to -20, NYC -15), with snow arriving on Thursday with highs near -5 C.

    Northern and central plains states will be sunny and cold, although somewhat less frigid than yesterday, with highs near -10 C then increasing cloud and outbreaks of light snow by late tomorrow in similar temperatures and east winds 30-50 km/hr.

    Canadian prairies remain frigid especially eastern half, into forests of northern Ontario where it is currently -43 C at Lansdowne House and Armstrong (north of Lake Superior). Readings near -40 C are likely at sunrise in a few hours across the eastern prairies and it will only recover to about -25 C later. Cloudy and a bit milder (-10 C) in parts of Alberta.

    British Columbia and parts of the Pacific northwest states are under a strong inversion, it's sunny and rather warm at about 10-13 C in the alpine and any slopes above low cloud, but most of the population is under a thick blanket of fog or low cloud with temperatures only able to reach 3-5 C.

    The southwest states are under warm sunshine with almost no humidity even along the California coast, highs are running 23-26 C and humidity levels are about 5%. Fortunately there is almost no wind as the area is rather dry.

    My local weather on Monday was very foggy all day, with only 50 metres visibility at sunset. Despite that, you could see the Moon and Jupiter dimly visible through the scudding fog banks, although Jupiter looked very faint (about a lunar diameter above the north pole of the Moon at 03z).


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Wednesday, 23 January, 2013

    Forecasts for Ireland


    ALERT for possible snow 3-5 cm in higher parts of inland west Munster as rain or sleet moving inland change to snow at higher elevations this morning (mainly above 200m elevations) ... ALERT for continued icy roads next two days, hopefully this problem will gradually become confined to smaller regions mainly east and at higher elevations but drive with caution and expect delays on a few routes as fog and even freezing rain could become part of this ongoing wintry scenario. ADVANCE ALERT for very strong winds possible in northern regions on Friday (slight risk) and again on Sunday (moderate risk).

    TODAY ... Somewhat milder in Atlantic coastal districts in cloud and rain, turning to sleet inland and to snow on higher terrain west of about Galway to Waterford (3-5 cm on hills), temperatures warming gradually near the coasts to 4-7 C but remaining closer to 1-3 C in the mixed precipitation inland ... meanwhile, cloudy but mainly dry further east and north, some later outbreaks of light snow or freezing drizzle possible, with highs 0-3 C. The rainfall potential is about 7-12 mm and it is possible that a heavier wet snow could develop from about Limerick to inland Cork (county) with a few places seeing 5-10 cm but this could then begin to melt later.

    TONIGHT ... Western half of the country should see a slight thaw in foggy, drizzly conditions and lows 2-4 C. Eastern half will remain in slightly colder air mass with freezing fog patches, a slight risk of light snow or freezing drizzle, and lows -3 to -1 C.

    THURSDAY ... Cloudy, a bit milder again, sleet or rain, although may remain wet snow mixing with sleet in parts of Leinster, with southeast to south winds 40-70 km/hr and highs near 5 or 6 C in most regions, possibly staying cold (1-3 C) east. Precipitation amounts fairly light with this weak warm front but could become a bit heavier in the northwest by evening (sleet to rain, 10 mm potential but dry in much of south and east).

    FRIDAY ... Rain and fog, milder, moderate south winds veering westerly late in the day, kiws 2-4 C and highs 7-10 C west, 3-7 C east. This rain could begin as sleet on higher ground in the east. Winds SSW veering later on to WSW 50-80 km/hr in exposed locations north, 35-60 km/hr elsewhere. Rain potential about 5-15 mm.

    SATURDAY ... Variable cloud, breezy, cooler again but only slight frost, lows near -1 C and highs near 7 C in westerly winds 30-50 km/hr., squally showers at times but also some welcome sunshine.

    SUNDAY ... Risk of very windy weather and squally showers, gales from a SW to WNW direction 50-90 km/hr (possibly stronger in north in a moderate risk of 90-120 km/hr winds), highs about 6-9 C.

    MONDAY to THURSDAY ... The month will end with a milder spell where temperatures could get back to double digits (10-13 C) and nights may become entirely frost-free again. This will persist perhaps for a day or two into February with an increasingly unsettled theme, and then I believe we may be tracking another significant cold outbreak from a north to northeast based arctic high appearing from across the polar regions and perhaps phasing with west-moving Siberian air in Russia. The timing on this is uncertain but I think it may be showing up around 1-3 February on European charts then getting close enough to be part of our forecast by 4-7 Feb (with the coldest weather due around 10-20 Feb). Confidence on this is not as high as more conventionally based forecasts as this is mainly a research-driven forecast theme. The window of opportunity for a major cold spell may not totally close until 10 March or so.


    Forecasts for Britain

    TODAY ... Cloudy, cold, some outbreaks of snow in central England giving local 5-10 cm amounts, widespread low cloud and freezing drizzle, highs generally -2 to +2 C.

    TONIGHT ... Cloudy, freezing fog patches, some light snow, lows -4 to -2 C.

    OUTLOOK ... Continued rather cold in the east and southeast with a very slow warming trend affecting mainly western districts and Scotland in a weak southwest flow that may become much stronger by the weekend, as a major storm with mixed precipitation types could develop then, bringing temperatures gradually above freezing and towards 6-8 C eventually. Very windy at times Friday to Monday in Scotland.


    North American forecasts

    Great Lakes and Midwest will remain very cold with mostly cloudy skies and some sunshine here and there, also some rather isolated squalls from open waters of Great Lakes on northwest or locally variable winds, highs generally about -12 C south to -19 C north. Northern Ontario remains in the deep freeze near -30 C daytime and -40 C overnight.

    Northeast states (east of the Appalachians) will be somewhat less windy today and a weak system moving southeast will bring 1-3 cm snowfalls to some places, traces elsewhere, with highs generally -10 to -5 C. New England however will be more sunny and intensely cold near -15 C daytime and -25 C tonight. Periods of snow arriving on Thursday night with highs near -7 C on Thursday and -2 C on Friday, 10-20 cm snowfall potential by Friday night, then another surge of quite cold arctic air for the weekend.

    Northern and central plains states will continue sunny and somewhat cold, but continuing to recover towards more normal highs of -5 to -10 C.By tonight, cloudy with light snow developing, lasting through Thursday with east winds 30-50 km/hr and somewhat colder again by Friday.

    In western Canada most regions remain frigid especially eastern prairies and today will only recover to about -22 C later with some very light snow developing. Cloudy and milder with light snow becoming heavier in central regions tomorrow (highs near -4 C) in parts of Alberta.

    British Columbia and parts of the Pacific northwest states will see overcast and rather mild weather with outbreaks of light rain, highs near sea level about 6-8 C, light snow inland mountains, highs 0-2 C.

    The southwest states continue to bask in warm sunshine with almost no humidity even along the California coast, highs are running 24-28 C and humidity levels are generally below 10%. This leads to very large diurnal ranges on the inland higher ground such as Utah and Nevada where nights can drop to -10 or -15 C then days warm up to 15 C.

    My local weather on Tuesday was mostly cloudy with some brief sunny intervals, the recent fog dispersed in a weak southerly wind flow, although it remains misty and visibility was about 5-10 km. The high was about 6 C.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Thursday, 24 January, 2013

    Forecasts for Ireland


    ALERT for the continuation of icy road conditions in central inland districts to mid-day and then again briefly tonight before milder air takes over ... ALERT for moderate rain and possible flooding from snow-melt runoff where streams drain higher snow-covered terrain on Friday ... ADVANCE ALERT for very strong winds possible in northern regions on Friday (60-90 km/hr) and again on Sunday and Monday (into Tuesday) (intervals of 80-120 km/hr).

    TODAY ... Cloudy, a bit milder again, sleet or rain, although may remain wet snow mixing with sleet in a few higher locations in east-central counties, with southeast to south winds slowly increasing to 40-70 km/hr and highs near 5 or 6 C in most regions, possibly staying cold (1-3 C) east and some parts of the midlands. Precipitation amounts fairly light with this weak warm front but could become a bit heavier in the west and northwest by evening (sleet to rain, 10 mm potential but dry in much of south and east).

    TONIGHT ... Rain arriving in west with fog and southerly winds 40-70 km/hr, sleet turning to rain further east by early morning hours, temperatures will be rising in most regions during the night from 2-4 C to 5-7 C. Rainfall amounts generally 10-20 mm.

    FRIDAY ... Rain and fog, milder, moderate south winds veering westerly mid-day west, and late in the afternoon east, highs 7-10 C west, 3-7 C east. Winds SSW veering later on to WSW 50-80 km/hr in exposed locations north, 35-60 km/hr elsewhere. Further rain potential about 5-15 mm, rivers or streams draining snow-covered higher terrain could see minor flooding as snow melt adds equivalent of 10 mm additional rainfall.

    FRIDAY NIGHT ... Windy and colder again, mixed wintry showers possible in west to northwest winds 40-70 km/hr, lows 2-4 C. Risk of snow or hail greater in higher parts of northwest.

    SATURDAY ... Variable cloud, breezy, highs near 7 C in westerly winds 30-50 km/hr., squally showers at times but also some welcome sunshine by afternoon, as showers become less frequent.

    SUNDAY ... Windy with the risk of very strong winds and squally showers, gales from a SW to WNW direction 50-90 km/hr (possibly stronger in north with a moderate risk of 90-120 km/hr winds), highs about 6-9 C. Large battering waves are expected by afternoon on the west coast.

    MONDAY-TUESDAY ... Further outbreaks of very strong SW winds as one or perhaps two more frontal waves race across Ireland from the west around the deep low pressure that we expect to arrive on Sunday (and then redevelop with secondary centres). Highs 8-12 C and frequent squally showers possible.

    OUTLOOK ... Mid-week and end of the month of January likely to continue rather mild and unsettled with highs possibly reaching 11-13 C briefly, then a gradual decline in more of a northwest flow can be expected, with the possibility of rather fast-paced changes back to very cold weather coming into view around the end of the week or start of the week of 3-9 February. Will be keeping a close eye on developments around the polar regions as this milder spell does not seem to have a long duration with rapid changes ahead in other regions around the hemisphere. Coldest conditions of the winter, possibly, can be expected in mid-February. The window of opportunity for a major cold spell may not totally close until 10 March or so.


    Forecasts for Britain

    TODAY ... Mostly cloudy, cold, some outbreaks of snow in a few areas of England giving local 2-4 cm amounts, mixed showers possible in Wales and southwest England, western Scotland ... widespread low cloud and patchy freezing drizzle with some icy roads as a result, highs generally -2 to +2 C for most but 4-7 C in some parts of the west.

    TONIGHT ... Cloudy, freezing fog patches, some snow or freezing rain may change to sleet or rain later in western regions, lows -3 to +2 C.

    FRIDAY ... Sleet or snow east, rain west, gradually turning milder with wintry mix turning to rain with cold foggy conditions and highs 2-5 C (7-10 C western Scotland, parts of Wales). Some flooding or ponding of water may begin in areas currently snow covered.

    WEEKEND OUTLOOK ... Windy, rather cold on Saturday with mixed wintry showers then milder Sunday although very windy central and north, gusts to 130 km/hr in western Scotland, 100 km/hr in exposed locations further south.

    OUTLOOK ... See Ireland forecast, all the same trends with further windstorm potential next week, turning milder.


    North American forecasts

    Great Lakes and Midwest will remain very cold with mostly cloudy skies and some sunshine here and there, also some squalls where N to NE winds come inland such as in western NY state, eastern Michigan, and the Chicago - Milwaukee region. Temperatures may actually drop during the day as a weak "thermal low" departs southeast and takes its slight store of heat captured from the Lakes away, to be replaced by some of the frigid air that has been settling in over regions further north and east for two days (Ottawa had a high of -24 C on Wednesday). Temperatures will be about -13 to -17 C in most places by mid-day and will be similar tonight as cloud advances from a weak low in South Dakota that will arrive on Friday to bring scattered light snow with locally heavy amounts from SE winds crossing the Lakes (some ice has now formed on bays but most of the Lakes are still open despite three days of deep freeze). Colder again Friday night into the weekend.

    Northeast states (east of the Appalachians) will be cloudy with further 2-5 cm snowfalls to some places, traces elsewhere, with highs -7 to -3 C. New England however will be mostly sunny until late afternoon and intensely cold near -15 C again today. Periods of snow arriving on Thursday night or Friday across this region with highs near -4 C on Friday, 5-15 cm snowfall potential by Friday night, then another surge of quite cold arctic air for the weekend.

    Northern and central plains states will see cloud and some light snow mixing with freezing drizzle, east winds and highs near -10 C. This light snow will end with flurries and 3-5 cm accumulations by early Friday and then it will turn slightly colder again with lows near -20 C to -30 C north, and highs about -10 C to -18 C north on the weekend. Much milder weather is due around Monday.

    In western Canada most regions remain frigid especially eastern prairies and today will only recover to about -26 C later with sunshine after ice fog dissipates (which it may not in a few places). Cloudy and somewhat milder with snow becoming heavier in central Alberta today, 10-20 cm potential around Edmonton, with highs near -4 C in southern parts of Alberta, but then turning a bit colder for Friday and then milder on the weekend.

    British Columbia and parts of the Pacific northwest states will see overcast and rather mild weather with further outbreaks of light rain, highs near sea level about 6-8 C, light snow inland mountains, highs 0-2 C. The rain is spreading inland across most of the western coastal regions now including parts of southern California.

    The southwest states except for southern California near the coast continue to bask in warm sunshine (increasing cloud west) with continued low humidity inland but more humid under low cloud in some places. Highs will be reduced somewhat to 21-24 C inland and 15-18 C coast.

    My local weather on Wednesday was overcast with rain at times, maybe about 10 mm, the first we've seen here in over a week which is unusual for January, and the high was 7 C. And no, I have no idea what a "kiw" is but I suspect it is due to typing without looking (low = kiw). Perhaps a new keyboard with the letters not worn off ?? :)


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Friday, 25 January, 2013

    Forecasts for Ireland


    ALERT for possible flooding from rain and snow-melt runoff where streams drain higher snow-covered terrain today ... ADVANCE ALERT for very strong winds possible in northern regions on Friday (60-90 km/hr) and again on Sunday and Monday (into Tuesday) (intervals of 80-120 km/hr).

    TODAY ... Foggy and milder with rain becoming more showery, brighter intervals mid-day, then some more rain, additional amounts of 5-15 mm. Moderate south winds veering westerly mid-day west, and late in the afternoon east, highs 7-11 C west, 5-9 C east. Winds SSW veering later on to WSW 50-80 km/hr in exposed locations north, 35-60 km/hr elsewhere. Rivers or streams draining snow-covered higher terrain could see minor flooding as snow melt adds equivalent of 10 mm additional rainfall.

    TONIGHT ... Windy and colder again, mixed wintry showers possible in west to northwest winds 40-70 km/hr, lows 2-4 C. Risk of snow or hail greater in higher parts of northwest.

    SATURDAY ... Variable cloud, breezy, highs near 7 C in westerly winds 30-50 km/hr., squally showers at times but also some welcome sunshine by afternoon, as showers become less frequent. Given the potential for strong winds Sunday to mid-week, this looks like a good day to check your property for anything that can be secured or moved as minor wind damage seems almost inevitable given the number of systems lining up for a chance to visit Ireland.

    SATURDAY NIGHT ... A rather windy frontal passage is expected before midnight west, late overnight east, and winds could reach 70-100 km/hr from the WSW with periods of rain and temperatures steady 5-8 C.

    SUNDAY ... Windy especially around sunrise with the risk of very strong winds and squally showers, gales from a SW to WNW direction 50-90 km/hr (possibly stronger in north with a slight risk of 90-120 km/hr winds), highs about 6-9 C. Large battering waves are expected by afternoon on the west coast. This is not the peak of the winds expected so be prepared.

    MONDAY-TUESDAY ... Further outbreaks of very strong SW winds as it now appears very likely that two more frontal waves race across Ireland from the west around the deep low pressure that we expect to arrive on Sunday (and then redevelop with secondary centres). Highs 8-12 C and frequent squally showers possible. Both of these strong wind events are timed for about mid-day on various models although there is a slight spread in timing and intensity. The range of possible wind speeds on this morning's guidance peaks at 120-160 km/hr in peak gusts. It would be wise to prepare on the basis of country-wide strong winds although some of the maps seem to indicate the northwest is more at risk than the southeast. There's enough spread to suggest any part of the country is at risk of some minor wind damage and a slight chance of moderate damage. The Tuesday event looks slightly stronger than the Monday event but that could be an insignificant difference when these systems arrive. Bear in mind there has to be considerable uncertainty in the details given that this whole scenario has boiled up from a low that was barely producing a circulation over the Great Lakes on Wednesday. That low is now a 980 mb low south of Newfoundland and models show it deepening to 930 mbs by Sunday morning.

    WEDNESDAY ... Still rather breezy and quite mild (SW backing S 40-70 km/hr) with some rain and highs near 10 C.

    THURSDAY ... Windy and turning colder in strong westerlies 60-100 km/hr, temperatures steady near 5-7 C then falling to 3-5 C, some showers becoming mixed or wintry on higher ground.

    OUTLOOK ... From this point on, models are generally showing us continued breezy to windy weather with a large mass of colder air edging ever closer from the north pole and in part from Russia as well. Development is sketchy on the model runs but my hunch is that this pattern could transform rather quickly into a very cold outbreak. Timing on that is uncertain, but I will throw out 3-5 February as the most likely time for big changes.

    Forecasts for Britain

    TODAY ... Sleet or snow east, rain west, gradually turning milder with wintry mix turning to rain with cold foggy conditions and highs 2-5 C (7-10 C western Scotland, parts of Wales). Some flooding or ponding of water may begin in areas currently snow covered.

    TONIGHT ... Cloudy, foggy with rain becoming sleety again in some northern and central to eastern regions, lows 3-5 C west to 1-3 C east.

    WEEKEND OUTLOOK ... Windy, rather cold on Saturday with mixed wintry showers then milder Sunday although very windy central and north, gusts to 130 km/hr in western Scotland, 100 km/hr in exposed locations further south.

    OUTLOOK ... See Ireland forecast, all the same trends with further windstorm potential next week, turning milder. Scotland is definitely at risk of some major wind damage by Monday and Tuesday from the maps on offer this morning, gusts to 170-200 km/hr could occur in exposed locations. It will also be very windy (gusts to 120-140 km/hr) further south in regions more exposed to the W-SW, meanwhile London and some parts of the Midlands may see gusts to about 90 km/hr.


    North American forecasts

    Briefly, light snow is developing west of Chicago and this will spread 3-5 cm amounts towards the northeast states with 10-20 cm localized lake-enhanced falls where southeast winds come inland from open water. It remains very cold in most regions of the east although a slight moderating trend will accompany this minor storm system. Then it will turn a bit colder again from the northwest due to frigid air spreading in from the Canadian prairies. Sunny and rather warm by contrast across the south-central and parts of southwest states, and rain on the west coast.

    My local weather on Thursday was cloudy with afternoon rain (5-10 mm) and a milder high near 10 C.

    Updates possible if the models change significantly at 3-4 p.m., otherwise, we'll review the wind potential in tomorrow morning's forecast. Lots of detailed discussion available on the forum threads.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Saturday, 26 January, 2013

    Forecasts for Ireland


    ALERT for very strong winds at frequent intervals from tonight into mid-week ... westerly gales possible in northern regions later this afternoon and evening, 70-110 km/hr, and again on Monday and Tuesday when even higher wind speeds are possible (100-150 km/hr) again from a westerly direction. That may not be the end of the strong winds either with some hints of another surge of strong winds on Thursday.

    TODAY ... Some bright or even sunny intervals this morning as cloud increases across the west in advance of an interval of rain likely by mid-day into the afternoon west, later afternoon east ... winds easing for a time, then increasing again from S-SW at 50-80 km/hr by late afternoon. Highs about 7-10 C with 10-20 mm rain likely before midnight.

    SATURDAY NIGHT ... A rather windy frontal passage is expected before midnight west, late overnight east, and winds could reach 70-110 km/hr from the WSW with periods of rain ending, and temperatures steady 5-8 C falling towards dawn in western counties to about 2-3 C. Some wintry showers could develop on higher ground in north.

    SUNDAY ... Windy, especially around sunrise, with squally showers, strong winds from a WSW to WNW direction 50-90 km/hr with a slight easing possible later in the day. Rather cold with passing showers of hail or sleet in some areas, trending to all rain near south coast and Dublin. Highs about 6-9 C. Large battering waves are expected on the west coast with a minor storm surge into Galway Bay (0.7 m above posted tides and this is already the full moon high tide). This is not the peak of the winds expected so be prepared.

    MONDAY ... After a rather cold and windy night (40-70 km/hr) with mixed wintry showers at times, lows near 2 C, the day will become very windy again with the risk of storm force wind gusts in exposed areas (expect at least SW 80-130 km/hr) with potential for some damage, periods of rain as temperatures peak around 8 C in gale force winds, so by no means "mild" although not wintry ... the peak winds should hit around noon to 6 p.m. but could last longer in some northern and eastern regions. Rainfalls about 10-15 mm.

    TUESDAY ... A second strong wind event is currently expected at about the same time and with similar weather outcomes, intervals of rain, some mixed or wintry showers in north, and peak winds once again SW 80-130 km/hr. Either of these two events could be upgraded or downgraded closer to the time but on balance they look about equally intense on the model runs. Lows near 2 C and highs near 8 C.

    WEDNESDAY ... Still rather breezy and turning somewhat milder in south-west winds of about 40-70 km/hr with some rain developing and highs near 10 C.

    THURSDAY ... Windy and turning colder in strong westerlies 60-100 km/hr (possibly 80-120 km/hr), temperatures steady near 5-7 C then falling by afternoon to 3-5 C, some showers becoming mixed or wintry on higher ground.

    FRIDAY to SUNDAY ... Rather cold with mixed wintry showers at times in blustery west to northwest winds, a brief interval of somewhat milder weather could push into the mix around Saturday but guidance is uncertain at this point, and I am seeing tentative signs that the expected much colder period could develop rather rapidly even as early as these first three days of February. Expect highs in the 4-7 C range and slight frosts at night in sheltered inland areas, snow on hills, mixed showers at lower elevations.

    OUTLOOK ... The model guidance can be pretty much discounted, but I continue to expect much colder weather to retun in February and the period beyond Monday 4th could see the arrival of very cold air masses or at least their presence in the forecast.

    Forecasts for Britain

    The systems are moving so rapidly that there is not much of a timing difference for Britain and Ireland, so basically, would say expect the forecasts above to be the guide with some of the events arriving 3-6 hours later in eastern England. In general, there will be somewhat more resistance to higher temperatures due to melting snow over parts of the east but otherwise all of the fast-moving systems and strong winds should have similar impacts in Brtain, in fact they could be even stronger winds for parts of western Scotland especially Monday and Tuesday, gusts to 170 km/hr seem possible. The changes back to colder weather seem rather large-scale and should come in at about the same time and pace also.

    North American forecasts

    Outbreaks of light snow will move through the eastern states although amounts could be trace to 2 cm in most places, although a few lake effect squalls might develop in a few locations to add 5-15 cm locally on northwest winds 40-60 km/hr later today. Highs generally -5 to -10 C as it stays quite cold, and today will be bright and colder than yesterday in the Midwest as a weak reinforcement of arctic air moves in from the north. Further snow will develop in the border regions of the plains and Canadian prairies. Milder into most of Alberta, cloudy with some light rain at times in the far west, but an area of heavier rain (turning to mountain snow) is moving inland from southern California towards the desert southwest region, 10-20 mm could fall even in Phoenix and Las Vegas. Reasonably warm at valley elevations with this rainfall, 16-19 C.

    My local weather on Friday was partly cloudy and very mild, high near 11 C.

    Updates may follow on the strong wind forecasts, if any new developments take place. The very strong low is currently at about 940 mbs well off to the west of Donegal and south of Iceland. It's not so much that low, but waves of new low pressure forming on its southern flank, that will produce the Monday and Tuesday strong winds, but tonight's blast of wind is from the deep low's fast-moving cold front.


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  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Sunday, 27 January, 2013

    Forecasts for Ireland


    My apologies for a somewhat late forecast, we have spent the day upgrading our computer memory and the system crashed about 0600h as I was about to post the forecast -- can say that this updated forecast makes very few changes from previous.

    Full moon has occurred already today at 0437h and this will be a factor in exceptionally high tides, possibly to storm surge levels, with the strong winds expected over the next three days (in particular, Monday mid-day).

    ALERT for very strong winds on Monday afternoon and evening with speeds in the 100-150 km/hr range, some possible wind damage and shoreline overtopping from combined storm surge and waves mainly west coast and some parts of south coast.

    TODAY ... Windy with squally showers, strong winds from a WSW to WNW direction 50-90 km/hr with a slight easing possible later in the day. Rather cold with passing showers of hail or sleet in some areas, trending to all rain near south coast and Dublin. Highs about 6-9 C. Large battering waves are expected on the west coast with a minor storm surge into Galway Bay (0.7 m above posted tides and this is already the full moon high tide). This is not the peak of the winds expected so be prepared.

    TONIGHT ... Continued blustery and cold with squally showers, some wintry on higher ground, lows 2-4 C, winds westerly 50-80 km/hr.

    MONDAY ... The day will become very windy again with the risk of storm force wind gusts in exposed areas (expect at least SW 80-130 km/hr) with potential for local gusts to 150 km/hr and some damage, periods of rain (10-20 mm) as temperatures peak around 8-10 C in gale force winds ... the peak winds should hit around noon to 6 p.m. but could last longer in some northern and eastern regions.

    TUESDAY ... A second strong wind event is currently expected at about the same time and with similar weather outcomes, intervals of rain, some mixed or wintry showers in north, and peak winds once again SW 80-130 km/hr. Lows near 2 C and highs near 8 C. Although some models have downgraded the intensity of this event, the ECM maintains it and we must wait and see how things unfold as the situation is too volatile for much precision -- this storm will not even begin to form until well into tonight.

    WEDNESDAY ... Still rather breezy and turning somewhat milder in south-west winds of about 40-70 km/hr with some rain developing and highs near 10 C.

    THURSDAY ... Windy and turning colder in strong westerlies 60-100 km/hr (possibly 80-120 km/hr), temperatures steady near 5-7 C then falling by afternoon to 3-5 C, some showers becoming mixed or wintry on higher ground.

    FRIDAY to SUNDAY ... Rather cold with mixed wintry showers at times in blustery west to northwest winds, a brief interval of somewhat milder weather could push into the mix around Saturday but guidance is uncertain at this point, and I am seeing tentative signs that the expected much colder period could develop rather rapidly even as early as these first three days of February. Expect highs in the 4-7 C range and slight frosts at night in sheltered inland areas, snow on hills, mixed showers at lower elevations.

    OUTLOOK ... The model guidance can be pretty much discounted, but I continue to expect much colder weather to retun in February and the period beyond Monday 4th could see the arrival of very cold air masses or at least their presence in the forecast. We've seen some very similar ideas to these on recent GFS runs but the timing keeps changing considerably.

    Forecasts for Britain

    The systems are moving so rapidly that there is not much of a timing difference for Britain and Ireland, so basically, would say expect the forecasts above to be the guide with some of the events arriving 3-6 hours later in eastern England. In general, there will be somewhat more resistance to higher temperatures due to melting snow over parts of the east but otherwise all of the fast-moving systems and strong winds should have similar impacts in Brtain, in fact they could be even stronger winds for parts of western Scotland especially Monday and Tuesday, gusts to 170 km/hr seem possible. The changes back to colder weather seem rather large-scale and should come in at about the same time and pace also.

    North American forecasts

    Rain has moved well inland now in the southwest, changing to wet snow in some higher areas, and this will create some heavy snow eventually on highest peaks in the Rockies of Colorado. Mild ahead of this system now into the central plains states, and slowly warming up in the still-frozen east but with just scattered outbreaks of sleet or snow developing ahead of this rapid change to milder conditions expected to sweep to the east coast by Tuesday and create a two-day return to the earlier mild spell, after which another cold wave is expected. The Canadian west is also warming slightly but remains well below freezing, until central Alberta and further west, where conditions are now getting fairly mild with outbreaks of rain at low elevations.

    My local weather on Saturday was mild with rain and a high near 11 C.

    All being well, keeping an eye on developments, updates when necessary if possible.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Monday, 28 January, 2013

    Forecasts for Ireland


    This is an update for the stormy conditions today, and some changes for Tuesday ... otherwise all forecasts remain the same and I will be back on-line around 1700h with my next forecast update. In the meantime, consult other threads on the weather forum for discussions on the evolving storm system.

    ALERT for very strong winds on Monday afternoon and evening with speeds in the 100-140 km/hr range, some possible wind damage and shoreline overtopping from combined storm surge and waves mainly west coast and some parts of south coast. ALERT for locally heavy rainfalls mainly before 1400h with some embedded thunderstorms, hail, and the slight risk of a tornado.

    OVERNIGHT ... Partly cloudy south, squally showers at times north, moderate westerly winds backing to SSW 40-70 km/hr then increasing to 70-110 km/hr towards sunrise in western counties as rain develops late tonight.

    TODAY ... MONDAY 28th ... Becoming very windy again with the risk of storm force wind gusts in exposed areas (expect SSW 90-120 km/hr veering to WSW 100-140 km/hr in most exposed areas, 80-110 km/hr more widespread) with potential for some damage, periods of heavy wind-driven rain (15-30 mm) as temperatures peak around 8-10 C .. the peak winds should hit around noon to 6 p.m. but could last longer in some northern and eastern regions. Risk of thunder and hail, and slight risk of a tornado, during and after passage of a strong cold front mid-day. Skies may clear partially in some southern regions but frequent squally showers will continue elsewhere.

    TUESDAY ... A second strong wind event is currently expected at about the same time and with similar weather outcomes, intervals of rain, some mixed or wintry showers in north, and peak winds once again SW 70-110 km/hr. Lows near 2 C and highs near 9 C. This system may not be as strong as Monday's for most especially across the south.

    WEDNESDAY ... Still rather breezy and turning somewhat milder in south-west winds of about 40-70 km/hr with some rain developing and highs near 10 C.

    THURSDAY ... Windy and turning colder in strong westerlies 60-100 km/hr (possibly 80-120 km/hr), temperatures steady near 5-7 C then falling by afternoon to 3-5 C, some showers becoming mixed or wintry on higher ground.

    FRIDAY to SUNDAY ... Rather cold with mixed wintry showers at times in blustery west to northwest winds, a brief interval of somewhat milder weather could push into the mix around Saturday but guidance is uncertain at this point, and I am seeing tentative signs that the expected much colder period could develop rather rapidly even as early as these first three days of February. Expect highs in the 4-7 C range and slight frosts at night in sheltered inland areas, snow on hills, mixed showers at lower elevations.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    UPDATE _ Monday, 28 January, 2013 _ 5:45 p.m.
    _____________________________________________

    Strong wind gusts are likely to continue until about 9 p.m. then should gradually reduce to moderate speeds in the 40-70 km/hr range as winds back from W to SW by morning. Another storm system is following a similar track but does not appear quite as strong, although it could catch Donegal with its strongest winds tomorrow mid-day. In general, this next event will be milder with a further 20-30 mm of rain possible. Winds for most of the country will peak during the late morning or early afternoon at about SW 50-80 km/hr but that may be closer to 70-120 km/hr in a few parts of the coastal northwest.

    Overnight lows of about 6-8 C for the south, 4-6 C north then highs during the day Tuesday of about 10-12 C.

    Wednesday will continue blustery and showery with highs near 9 C in a steady southwest wind of about 40-70 km/hr. This will once again rise to somewhat stronger levels overnight into Thursday morning with a heavier burst of rain (another 15-25 mm possible) then it should begin to turn colder in stages on Thursday as winds veer more westerly at 50-80 km/hr. Passing squally showers could become wintry on higher ground through late Thursday into Friday as winds veer further to the northwest.

    By Saturday it should begin to clear on strong northwest to north winds although some lines of showers could develop near the west coast, and it will be quite cold especially in the wind (50-80 km/hr) with highs of 5-7 C.

    Will revisit the longer range forecast with the usual morning forecast as I am hoping that today will see a solution to my computer issues.

    Just briefly, the weather in Britain will follow this same pattern except to mention that Scotland has yet to see the full force of today's storm and can expect an interval of 80-130 km/hr SW gales shortly especially on the southwest coast. That should blow through by about 0300h after which the general sequence for the Irish forecast can be applied to Britain's weather with perhaps an average six hour lag as the systems take that long to cross the region.

    And even more briefly, in North America the big story is a rapid warming trend set to last two days in central and eastern states which have been in the deep freeze for the past week -- now temperatures are soaring into the range of 13-18 C from Chicago to New England and 20-24 C further south (this won't reach the east coast until tomorrow morning). The resulting mild spell will last about halfway through Wednesday in the Midwest and into the early hours of Thursday in the east, after which it will turn sharply colder on strong northwest winds.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Tuesday, 29 January, 2013

    Forecasts for Ireland


    ALERT for strong winds in some parts of northwest this afternoon and evening (Tues 29th) and also for heavy rainfalls in a few places 15-25 mm.

    OVERNIGHT ... Cloudy, mild, moderate southwest winds 40-70 km/hr, an interval of rain in southwest before morning. Lows 4-7 C.

    TODAY ... Windy and mild with further rain, 15-25 mm possible, moderate southwest winds for most (50-80 km/hr) but strong gusts in coastal northwest towards late afternoon, 70-120 km/hr in exposed locations. Generally it will not be as windy as Monday, but milder with highs 10-12 C.

    WEDNESDAY ... Blustery and feeling rather cold most of the day, milder by late afternoon and evening, strong westerly winds 50-80 km/hr backing to southerly by nightfall. Morning lows 2-4 C and afternoon or perhaps evening highs of about 9 C. Further rainfalls about 10 mm.

    THURSDAY ... Early morning strong winds and squally showers, winds SW veering to W 60-100 km/hr, temperatures steady near 8 C then slowly falling during the day to about 3-5 C. Mixed wintry showers may develop in higher parts of the north.

    FRIDAY ... Windy and cold with mixed wintry showers, some snow on hills, winds NW to N 50-80 km/hr, lows near 1 C and highs near 5 C.

    SATURDAY ... Windy and cold, more isolated wintry showers, some sunshine especially south, lows near -1 C and highs near 5 C. Winds northerly backing to westerly late in day 50-80 km/hr.

    SUNDAY-MONDAY ... Breezy, milder, rain arriving. Highs 9-12 C.

    FURTHER OUTLOOK ... Turning much colder in stages, details not too clear yet, probably some snow risk eventually.

    Britain & North America

    See my previous forecast for a few updates there, will get back to a more regular forecast schedule soon (not sure on timing of solutions to computer issues so posting this early just in case).


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Wednesday, 30 January, 2013

    Forecasts for Ireland


    ALERT for strong winds today peaking tonight with gusts to 120 km/hr in parts of south and west ... ADVANCE ALERT for increasingly severe wintry weather Friday to Tuesday culminating with strong winds and snow in some regions, and the risk of a prolonged interval of severe wintry weather next week and beyond.

    TODAY ... Partly to mostly cloudy, strong SW to W winds 60-90 km/hr with some higher gusts, and passing squally showers more frequent in north, feeling cold in the wind although highs 8-10 C. Rain will arrive late afternoon in west.

    TONIGHT ... Very windy (SSW 60-100 km/hr) with 10-20 mm rain followed by some hail and thunder, wind shift to westerly with some gusts to 120 km/hr possible, temperatures steady near 10 C then falling to about 3-5 C.

    THURSDAY ... Windy (WSW 50-80 km/hr) and rather cold with passing showers of hail or sleet (snow on higher ground possibly) and highs 6-7 C with somewhat calmer conditions by late afternoon and evening, clearing.

    FRIDAY ... Clear intervals, slight frost early morning, lows -1 to +3 C, then increasing cloud, highs 7-9 C, with rain for Munster and showers elsewhere, rain persisting overnight in the south with winds becoming NE 40-70 km/hr. Lighter winds and mostly dry further north.

    SATURDAY ... Rain overnight in south (totals of 15-25 mm), then windy and cold with mixed wintry showers, some snow on hills, winds northeast backing to northwest 40-60 km/hr for most but 50-90 km/hr possible in Wexford and parts of southeast closer to departing low. Connacht and west Ulster could have a less windy and dry interval mid-day then cloud with drizzle and westerly winds by evening.

    SUNDAY ... Cloudy, moderate WSW winds 40-70 km/hr, turning milder in stages, 5-10 mm rainfalls, highs near 10 C by evening.

    MONDAY ... Windy and mild, highs near 11 C, periods of rain, strong SW to W winds 80-110 km/hr. Sharply colder in west by late afternoon or evening.

    TUESDAY ... Very windy and cold with wintry showers becoming snow in parts of west and north, some accumulations in Connacht and Ulster, winds WNW at least 70-110 km/hr and possibly higher gusts, blizzard-like conditions in parts of west and north ... temperatures steady 0-2 C and possibly lower at times in higher elevations and/or during and after snowfall.

    FURTHER OUTLOOK ... Models are trending towards severe wintry conditions and in fact the GEM model does have snow potential mid to late week, European model just about as severe, GFS wants to hold on to a more mixed pattern but still with some wintry days between slightly milder ones. Overall would now say that chances of a severe wintry episode are rising towards perhaps 70% for period 5-15 February (and possibly beyond).

    Forecasts for Britain

    TODAY ... Very strong winds in Scotland gusting to 150 km/hr in north and west, 120 km/hr east and south, trending to more moderate westerlies in England and Wales (60-90 km/hr), highs near 6 C north to 9 C south. Passing squally showers in most areas especially western regions.

    TONIGHT ... Windy with thunder and heavy rain at times, lows 7-9 C south and 4-6 C north. Wind gusts to 120 km/hr in north-central England and parts of Wales.

    THURSDAY ... Windy, passing showers, highs near 7 C.

    FRIDAY ... Isolated frost to start, then cloudy, rain across the south by late in the day, some heavy falls overnight into Saturday (30 mm) ... highs 7-9 C.

    WEEKEND OUTLOOK ... Windy and colder with mixed wintry showers, then milder by late Sunday.

    NEXT WEEK ... Windy and mild on Monday then very windy and severe wintry conditions developing Tuesday and possibly lasting all week with heavy snow potential in sea effect streamers then more widely from low pressure, possible blizzard conditions developing, temperatures not far from -2 C much of the week after starting around 10 C.

    North American forecasts

    Spring like warmth in the east (15-20 C) and almost late spring conditions in the southeast (25-27 C) with an outbreak of severe thunderstorms and heavy rains to follow from a front currently about Chicago to Houston Texas. This may produce a tornado outbreak in much of the south central and southeast, Ohio valley regions later. New England gets into the milder air more gradually after sleet and rain, fog (7 C).

    Further west and north, very cold air is massed over inland western Canada and will push as far south and east as Kansas to Wisconsin by afternoon, in some places temperatures currently 15-17 C will fall to -15 C by tonight after a brief 2-4 cm snowfall and northerly winds 50-80 km/hr. The northern plains and prairies are sunny and very cold with highs near -24 C. Western regions have stayed milder with outbreaks of light rain trending to partly cloudy in the desert southwest.

    My local weather on Tuesday was cloudy, foggy and drizzly with a high of about 7 C.

    A wild ride ahead, weather watchers ... strap in and hold on.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    UPDATE to ALERT _ 0045h Thursday 31 Jan 2013
    ____________________________________________

    ALERT upgraded to severe thunderstorm alert for Dublin region including Dublin, Kildare and Meath counties, north into Ulster ... squall line approaching rapidly, will arrive Dublin about 0130-0200h, expect brief interval of heavy rain, intense lightning, possible hail and wind gusts to 120 km/hr in wind shift SSW to WSW. Strong gusty winds will continue for several hours after passage.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Thursday, 31 January, 2013

    Forecasts for Ireland


    ALERT for strong winds continuing today until mid-day with gusts to 130 km/hr in parts of north and west ... ADVANCE ALERT for increasingly severe wintry weather especially after Tuesday culminating with strong winds and snow in some regions, and the risk of a prolonged interval of severe wintry weather next week and beyond.

    THURSDAY ... Windy in all regions (at least WSW 50-80 km/hr) but continuing severe gusts 80-130 km/hr in parts of west and north, easing to 50-80 km/hr about mid-day ... rather cold with passing showers of hail or sleet (snow on higher ground possibly) and highs 6-8 C with somewhat calmer conditions by late afternoon and evening, clearing.

    TONIGHT ... Clear intervals developing, frost inland, lows -3 to +2 C.

    FRIDAY ... Increasing cloud, moderate NW winds 40-70 km/hr, highs 7-9 C, with some showers and some hail, rain persisting into the evening in the southeast with winds becoming NNE 40-70 km/hr. Lighter winds and mostly dry further north. Rainfalls generally 2-5 mm.

    SATURDAY ... Rain overnight in south (totals of 5-10 mm), then windy and cold with a few mixed wintry showers, some snow on hills, winds northeast backing to northwest 40-60 km/hr. Connacht and west Ulster could have a less windy and dry interval mid-day then cloud with drizzle and westerly winds by evening.

    SUNDAY ... Cloudy, moderate WSW winds 40-70 km/hr, turning milder in stages, 5-10 mm rainfalls, morning lows -2 to +3 C with some frost, highs near 10 C by evening.

    MONDAY ... Windy and mild to start, after a mild and breezy night with temperatures steady 6-8 C, then mid-day highs near 11 C, periods of rain, strong SW to W winds at least 50-80 km/hr. Sharply colder in west by late afternoon or evening with risk of stronger wind gusts developing.

    TUESDAY ... Very windy and cold with wintry showers becoming snow in parts of west and north, some accumulations in Connacht and Ulster, winds WNW at least 50-80 km/hr and possibly higher gusts, blizzard-like conditions in higher parts of west and north ... temperatures steady 2-5 C and possibly lower at times in higher elevations and/or during and after snowfall.

    FURTHER OUTLOOK ... Some of the models have cold feet about the cold spell (if you follow my drift) but the leader of the pack (ECM) is sticking to its guns and the GEM has only made slight adjustments, so confidence remains about 60-70 per cent concerning a spell of relatively severe winter weather developing Tuesday-Wednesday and perhaps settling in for a while, as eventually the stalled Atlantic high develops a ridge through northwest Ireland and Scotland towards Scandinavia and a link to the Siberian high. For those looking for the most severe outcome, this set-up would need to be somewhat further north but it does hint at sub-freezing daytime temperatures and sharp frosts into the -7 C range, even if snowfall chances in some of the patterns shown are modest (for Ireland ... for the southeast parts of England the set-up is more conducive to snow at times). I continue to suspect the models will not get the full "signal" for severe winter patterns until the weekend or into early next week, then we may be looking at more reliable projections of severe cold and some snow into mid-February.

    Forecasts for Britain

    TODAY ... Windy, with severe gusts in parts of Scotland and northwest England (westerly 80-140 km/hr), passing showers of rain or hail, winds further south about 50-80 km/hr. Highs near 7 C.

    TONIGHT ... Less windy, showers ending, some sleet on higher ground, frosts developing in valleys central and north, lows about 2 C on average.

    FRIDAY ... Isolated frost to start, then cloudy, showers developing and a steady rain across the south by late in the day, some heavy falls overnight into Saturday (20 mm) ... highs 7-9 C.

    WEEKEND OUTLOOK ... Windy and colder with mixed wintry showers, then milder by late Sunday.

    NEXT WEEK ... Windy and mild on Monday then very windy and severe wintry conditions developing Tuesday from north to south (less severe in southern England) and possibly lasting all week in north and east with heavy snow potential in sea effect streamers then more widely from low pressure, possible blizzard conditions developing, temperatures not far from -2 C much of the week after starting around 10 C. Parts of southwest England and Wales may be less impacted by the severe cold and could see highs of 3-5 C with mixed wintry showers.

    North American forecasts

    Eastern regions mild to start but after some rain and sleet, turning much colder with snow flurries, temperatures dropping steadily from 10-15 C to about -10 C by evening. Great Lakes snowbelts may see 10-20 cm snow locally in strong west to northwest winds, morning temperatures 2-5 C then about -5 to -10 C by evening. Clear and cold in central regions, although moderating as winds become light then southerly. Highs about 0-3 C in central plains to -10 C northern plains and -20 C Canadian prairies, some outbreaks of snow closer to the Rockies, and then milder from there to west coast. Partly cloudy and warm in southwest and south central states, a few showers developing on weak frontal systems.

    My local weather on Wednesday was foggy and mild with drizzle and highs near 11 C. Currently very foggy and 6 C at quarter to midnight.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Friday, 1 February, 2013

    Forecasts for Ireland


    ADVANCE ALERT for potential severe wintry weather arriving on Monday night in the form of wintry showers, snow on at least higher ground, and very strong winds for part of Tuesday

    TODAY ... Becoming rather windy again from Connacht south during the morning, as winds rapidly increase to WNW 50-80 km/hr with potential for some higher gusts around squally showers of rain, hail and even snow on higher terrain. Some of these will be thundery. Rainfalls rather hit and miss with 3-7 mm for most locations. Feeling very cold at times despite almost normal highs of 6-8 C. There will be some sunny intervals later with gusty northwest to north winds 40-70 km/hr.

    You may recall that we were discussing a system moving across the south with rain into tonight (and across southern England on Saturday) -- that has moved through rather early and what's left of it will be picked up by today's advancing trough, a rather short-term model error which, if it occurred on a similar scale during the upcoming colder interval, would lock in much colder conditions. (of course, there might also be a compensating shift in the other direction)

    TONIGHT ... A few brief showers becoming mostly confined to coastal locations, and winds inland may become rather light but will continue moderate N to NE in exposed areas. Slight frost could develop inland with lows about -2 to +3 C.

    SATURDAY ... Morning conditions will be variable in northerly winds and passing showers in a few places, some of them wintry, but a mainly dry interval should develop mid-day to afternoon with considerable sunshine and winds backing gradually from northerly to westerly. It will remain rather cold except in the coastal west and northwest, highs for most 4-7 C but 8-10 C in coastal west and northwest. Rain or drizzle will arrive during the night and sweep southeast across the country possibly starting as sleet in higher parts of the southeast.

    SUNDAY ... Rain ending, after perhaps 5-7 mm then partly cloudy to overcast and milder, winds backing further to WSW and increasing to 50-80 km/hr during the afternoon and evening. There may be some stronger gusts at times during the overnight hours and the daytime high of 8-11 C may persist through the night.

    MONDAY ... Windy and turning colder in stages, with showers or drizzly rain in a strong to gale force westerly, temperatures steady 7-9 C then slowly falling to about 3-5 C later, showers possibly becoming wintry by evening especially in Connacht and West Ulster.

    TUESDAY ... Very windy and cold with mixed wintry showers of hail, sleet and snow (accumulating to 3-7 cm on some northern hills) with west to northwest gale force winds 70-110 km/hr, risk of some severe gusts in the north, and temperatures steady in the 2-4 C range possibly dropping to 0-2 C where snow accumulates. The rain-snow line will rapidly fall to about 150m or lower and some of the passing squally showers could be thundery with large hail or snow. Blizzard-like conditions may develop in higher sections of the north. This is almost like the "Greenland Express" we saw in Dec 2010.

    WEDNESDAY ... Windy and very cold with passing showers of hail, sleet or snow, morning lows -1 to +1 C and afternoon highs 3-5 C but possibly colder over snow-covered areas. Not quite as windy as the previous day (NW 50-80 km/hr) with frosty conditions by evening and overnight.

    OUTLOOK ... The models probably have a rather tenuous grasp of developments as the jet stream dives well to the south and a link begins to develop from an Atlantic high that is showing some signs of moving further away to the west, and a ridge of Siberian origins building into northern Scandinavia. This linkage could also be disrupted by wintry low pressure systems from an origin to the northwest to north. Expect at least a modified cold spell with severe night frosts and highs between -1 and +3 C and the possibility of more severe cold than that with chances for snow.

    Forecasts for Britain

    TODAY ... Rain across the south (10-15 mm) while showers, some wintry on higher ground, sweep across northwest England and Wales towards the Midlands. Windy and cold in Scotland with mixed wintry showers. Highs today will range from 3-6 C in the north to 7-11 C in the south.

    TONIGHT ... Showers becoming increasingly wintry but then some clearing and isolated frosts with lows about -2 to +3 C.

    WEEKEND OUTLOOK ... Similar to eastern Ireland, cold and bright for Saturday with wintry showers near the North Sea, then cloudy with light rain at times on Sunday and milder.

    FURTHER OUTLOOK ... The same blast of cold air will arrive Monday night into Tuesday, then Britain will be even more likely to see wintry conditions for several more days and possibly some isolated heavy snowfalls as well as severe frosts to -7 C or lower, as the flow becomes increasing northerly to northeasterly.

    Forecasts for North America

    The mild spell ended dramatically on Thursday for millions in the Great Lakes and northeast, and now it's very cold with snow squalls in strong W to NW winds, highs -5 to -2 C. The milder weather has been swept east to Newfoundland where it may reach 10-12 C before falling to -5 C later, as the low deepens to 940 mbs near the Labrador coast (bringing 30-50 cm of snow to Goose Bay and a few isolated towns in northern Quebec). This blizzard will move into the eastern arctic islands. Meanwhile, light snow is spreading southeast with a weak system near the Minnesota-North Dakota border towards Chicago. South of about Missouri to Colorado, it is much warmer and the weather is spring-like with highs of 20-24 C. The southeast states are more under the influence of the cold arctic air but will feel a bit of the milder trend later and into the weekend. The west remains quiet, relatively mild and in some places quite foggy.

    My local weather on Thursday was foggy with drizzle and highs near 8 C.


  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Saturday, 2 February, 2013

    Forecasts for Ireland


    Situation: Instead of posting a detailed situation report, I have inserted comments into the forecasts to help explain both the severity and complexity of the weather approaching in two or three days' time. These comments are after the forecasts for the days and if you're in a hurry to read just forecasts then scroll down to the next day when the text gets into a discussion.

    ADVANCE ALERT for potential severe wintry weather arriving on Monday night in the form of wintry showers, snow on at least higher ground, and very strong winds gusting to 110 km/hr at times on Monday and Tuesday. With somewhat less confidence, we are also looking further ahead to possible severe cold by the following weekend if some models are correct, and that might bring temperatures as low as -10 C over any snow cover that develops, otherwise about -7 C. There might also be limited recovery in the daytime with the possibility of freezing fog and "ice days" where daily maxima are also below freezing. Confidence on the early phase of strong winds and wintry showers is about 80% now, and about 50-60 per cent on the severe cold to follow (for Ireland, for the eastern half of the U.K. this is more like 80 per cent as well).


    TODAY ... A bright and cold start in most places, watch for patchy ice in shaded locations until almost mid-day, and there may be a few lines of mixed wintry showers near both east and west coasts, then generally sunny around mid-day as winds back gradually from northerly to westerly at moderate speeds of 30-50 km/hr. It will remain rather cold except in the coastal west and northwest, highs for most 4-7 C but 8-10 C in coastal west and northwest. The west will begin to see cloud from the approaching frontal system during the late morning and mid-day.

    TONIGHT ... Rain or drizzle will arrive during the evening or overnight in western counties, and will sweep southeast across the country possibly starting as sleet in higher parts of the southeast. This rainfall will bring amounts of about 5-7 mm by morning, and temperatures may fall slightly after sunset then begin to rise slowly; "lows" will be about 2-4 C for most and perhaps -1 C in a few inland valley locations in the south and east. By morning it will be about 5-7 C in a moderate westerly wind with rain or drizzle at times.

    SUNDAY ... Rain ending for a time during the morning, after perhaps 5-7 mm then partly cloudy to overcast and milder, winds backing further to WSW and increasing to 50-80 km/hr during the afternoon and evening. There may be some stronger gusts at times during the overnight hours and the daytime high of 8-11 C may persist through the night. More rain will arrive in the west during the afternoon and reach eastern regions by evening.

    MONDAY ... Windy and turning colder in stages, with showers or drizzly rain in a strong to gale force westerly, temperatures steady 7-9 C during the early morning hours, then slowly falling to about 3-5 C later in the morning to mid-day for south which will see the cold front passing around 10:00 a.m. to noon, later showers possibly becoming wintry by afternoon and evening especially in Connacht and West Ulster, as temperatures continue to drift down in a strong westerly wind. There could be some hail and thunder with a second cold front arriving during the overnight hours. The overnight period will be very windy with blustery showers of sleet, hail and snow, and possibly some thunder, with temperatures not far from 1-2 C on average (the flow is coming straight from Greenland and over the near Atlantic Ocean surface temperatures of 9-10 C will warm the lower levels of this very cold air to about 3-5 C but those temperatures will only be felt briefly on land near sea-level, then temperatures will fall off rather quickly in the air mass when it loses contact with the ocean -- this process will also generate a strong potential for thundery showers some of which could be snow and hail).

    TUESDAY ... Very windy and cold with mixed wintry showers of hail, sleet and snow (accumulating to 3-7 cm on some northern hills) with west to northwest gale force winds 70-110 km/hr, risk of some severe gusts in the north, and temperatures steady in the 2-4 C range possibly dropping to 0-2 C where snow accumulates. The rain-snow line will rapidly fall to about 150m or lower and some of the passing squally showers could be thundery with large hail or snow. Blizzard-like conditions may develop in higher sections of the north. It will feel exceptionally cold in the wind and conditions may become severe for livestock in higher elevations especially. The northern coastal areas will be seeing near-hurricane force wind gusts at times and together with western Scotland they may be experiencing this as a sort of wintry version of a tropical storm force event (force 10-12 winds in the range of 50-70 knots over the North Atlantic both west and north of Donegal Bay).

    A slight "warm sector" may rotate around the storm so precipitation types may continue to change and it won't always be colder in the north than the south because of this rotation of slightly milder air (this sector may be around 3-4 C instead of 1-2 C).

    WEDNESDAY ... Windy and very cold with passing showers of hail, sleet or snow, morning lows -1 to +1 C and afternoon highs 3-5 C but possibly colder over snow-covered areas. Not quite as windy as the previous day (NW 50-80 km/hr) with frosty conditions by evening and overnight.

    Some models indicate that Wednesday could be quite stormy in eastern as well as some exposed western counties due to sea effect streamers of mixed wintry showers if not all snow. The deep low that is expected to track north of Scotland producing all the active weather of Monday and Tuesday will then dive southeast towards Belgium and if it maintains a strong gradient this will bring gale force NNW veering to NNE winds across the Irish Sea. Other models show this somewhat more subdued although by no means settled or pleasant weather. So that wind forecast could upgrade or slightly downgrade closer to the time.

    THURSDAY to SUNDAY ... Previous comments about a possible connection to much colder air masses from the far north or east are still valid and appear to be driving the European model more than most of the others, while the rest of the models tend to be struggling to resolve possible interludes of very cold and not so cold northwesterly type flow patterns taking turns over the next week or two. Hence the outlook for Thursday to Sunday is rather uncertain but if the European model is correct, it could turn out bitterly cold with some sunshine at times, some wintry showers mainly in streamers from the Irish Sea, and most of those would be snow as temperatures would be struggling to reach even 2 C in the daytime and would easily fall below -5 C at night, perhaps as low as -10 C over snow cover. The best advice on this period is "stay tuned" because if the weather models can't decide, we have to make an educated guess (even when they all agree, sometimes they are all a bit off the mark when it comes time to verify, but any situation with large differences model to model becomes a guessing game for forecasters -- the European model is not often colder than the GFS so that has me thinking the coldest solution is plausible, also it's indicated in my research).


    Forecasts for Britain

    TODAY ... Sunny intervals central and north, scattered wintry showers with some accumulations of hail or snow in east, breezy to windy and cold, highs about 3-5 C, winds northerly 40-70 km/hr but some higher gusts near North Sea coasts and in parts of Wales and southwest England.

    TONIGHT ... Wintry showers becoming isolated, clear intervals fading to cloud and later drizzle or light rain moving in from northwest, on milder westerly winds, temperatures reaching lows around midnight in most regions (0-2 C) then rising slowly to 4-6 C.

    FURTHER OUTLOOK ... Similar to Ireland, windy and milder on Sunday with some rain at times, highs 8-11 C, then during Monday, the same blast of cold air will arrive and create scattered winter-storm conditions into Tuesday and Wednesday, with very strong winds (W 80-140 km/hr for parts of Scotland, and 70-120 km/hr further south) ... then Britain will be very likely to see wintry conditions for several more days and possibly some isolated heavy snowfalls as well as severe frosts to -7 C or lower, as the flow becomes increasing northerly to northeasterly. This severe cold could persist for quite some time. There will also be frequent snowfalls across northern France and most of western-central Europe during this cold spell, with travel disruptions likely to develop.

    Forecasts for North America

    Snow will move through parts of the lower Great Lakes with a "clipper" system as they are known, giving Chicago perhaps 5-10 cm. It will remain bitterly cold in parts of the Midwest, Great Lakes and inland northeast U.S., and very windy across far eastern Canada as a 939 mb low was analyzed earlier near Baffin Island (that is about the intensity of Sandy a day before landfall). Blizzard conditions are spreading northwest into the eastern arctic as a result. Meanwhile it remains very cold also in the prairies of western Canada, trending to snow in Alberta and mild, foggy and wet inland B.C., partly cloudy and very mild near the coast. The southwest U.S. to the Gulf coast are in a warmer, dry pattern now. The coldest air is confined to an area north of about Washington D.C. to St. Louis to central Montana.

    My local weather on Friday was cloudy with haze and a bit of weak sunshine at times, mild with a high near 10 C.


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  • Registered Users Posts: 14,279 ✭✭✭✭M.T. Cranium


    Important: Please note legal disclaimer which can be seen at bottom of post 2565 dated 24 July 2012.

    Sunday, 3 February, 2013

    Forecasts for Ireland


    ALERT for potential severe wintry weather arriving on Monday (afternoon to evening) in the form of wintry showers, snow on at least higher ground, and very strong winds gusting to 110 km/hr at times on Monday and Tuesday. With somewhat less confidence, we are also looking further ahead to possible severe cold by the following weekend if some models are correct, and that might bring temperatures as low as -10 C over any snow cover that develops, otherwise about -7 C. There might also be limited recovery in the daytime with the possibility of freezing fog and "ice days" where daily maxima are also below freezing. Confidence on the early phase of strong winds and wintry showers is about 90% now, and remains about 50-60 per cent on the severe cold to follow (for Ireland, for the eastern half of the U.K. this is more like 80 per cent as well). It should be noted that the GFS model has begun to show this severe cold on today's guidance, and the leading European model continues about as before, so now it's only some of the less reliable guidance that is hesitant on the severe cold.

    TODAY ... Rain ending soon in the southeast, becoming partly cloudy to overcast and quite mild, as winds back further to WSW increasing to 50-80 km/hr during the afternoon and evening. There may be some stronger gusts at times by late afternoon especially near the northwest coast. The daytime high of 8-11 C may persist through part of the night. More rain will arrive in the west during the afternoon and reach eastern regions by evening.

    TONIGHT ... Periods of rain (5-10 mm), windy and rather mild in east and south, turning colder towards morning in the west and north. Temperatures steady 8-11 C then falling to 3-5 C in west and north, 6-8 C east and south. Winds WSW 50-80 km/hr with some higher gusts.

    MONDAY ... Windy and turning colder in stages, with showers or drizzly rain in a strong to gale force westerly, temperatures steady 7-9 C during the early morning hours, then slowly falling to about 3-5 C later in the morning to mid-day for south which will see the cold front passing around 10:00 a.m. to noon, later showers possibly becoming wintry by afternoon and evening especially in Connacht and West Ulster, as temperatures continue to drift down in a strong westerly wind. There could be some hail and thunder with a second cold front arriving during the overnight hours. The overnight period will be very windy with blustery showers of sleet, hail and snow, and possibly some thunder, with temperatures not far from 1-2 C on average (the flow is coming straight from Greenland and over the near Atlantic Ocean surface temperatures of 9-10 C will warm the lower levels of this very cold air to about 3-5 C but those temperatures will only be felt briefly on land near sea-level, then temperatures will fall off rather quickly in the air mass when it loses contact with the ocean -- this process will also generate a strong potential for thundery showers some of which could be snow and hail).

    TUESDAY ... Very windy and cold with mixed wintry showers of hail, sleet and snow (accumulating to 3-7 cm on some northern hills) with west to northwest gale force winds 70-110 km/hr, risk of some severe gusts in the north, and temperatures steady in the 2-4 C range possibly dropping to 0-2 C where snow accumulates. The rain-snow line will rapidly fall to about 150m or lower and some of the passing squally showers could be thundery with large hail or snow. Blizzard-like conditions may develop in higher sections of the north. It will feel exceptionally cold in the wind and conditions may become severe for livestock in higher elevations especially. The northern coastal areas will be seeing near-hurricane force wind gusts at times and together with western Scotland they may be experiencing this as a sort of wintry version of a tropical storm force event (force 10-12 winds in the range of 50-70 knots over the North Atlantic both west and north of Donegal Bay).

    Note: A slight "warm sector" may rotate around the storm around afternoon to evening hours of Tuesday, so precipitation types may continue to change as this rotates across Ireland (it will probably last about 3-6 hours) and it won't always be colder in the north than the south because of this rotation of slightly milder air (this sector may be around 3-4 C instead of 1-2 C).

    WEDNESDAY ... Windy and very cold with passing showers of hail, sleet or snow, morning lows -1 to +1 C and afternoon highs 3-5 C but possibly colder over snow-covered areas. Not quite as windy as the previous day (NW 50-80 km/hr) although some strong or even severe gusts are still possible with a trough rotating around the low, which by this time will be in the eastern to southern North Sea. Partly due to scattered snow cover developing, there may be frosty and icy conditions by evening and overnight, especially in higher elevations of the east and north.

    THURSDAY ... Breezy to windy (NW to N 40-70 km/hr) and cold with passing mixed wintry showers, morning lows -2 to +2 C and afternoon highs 4-6 C in west, 2-4 C east. Some further snow accumulations on higher ground mostly.

    FRIDAY ... There could be a brief interval of rain across the southwest as a weak rebound of milder air pushes back slightly, but this could set off mixed wintry precipitation elsewhere in variable winds, highs generally 3-5 C but possibly a bit milder in Kerry, Cork and Limerick into parts of Clare (5-7 C).

    WEEKEND OUTLOOK ... Colder again with the possibility of some snow streamers in eastern and central counties, as well as some parts of the northwest. Winds generally from the northeast although ranging from east to a little west of due north as troughs move southwest around the remnants of the earlier storm (by now in the Alps region of Europe). Severe cold may develop during the weekend, but for now we will suggest lows -5 to -2 C and highs -1 to +3 C with variable skies and some sunshine, also some patchy ice fog well inland, streamers of snow near east coast and Donegal Bay. The coldest part of this pattern is suggested for about Monday 11th and could persist for several days. At some point there could be highs below freezing and lows in the -10 to -7 C range, even colder if snow cover developed and clear skies followed. This scenario is the most likely, but there is some chance of a milder outcome with highs in the 4-7 C range and mixed or sleety precipitation in this time frame.


    Forecasts for Britain

    TODAY ... Periods of rain heavy at times in some southern counties, foggy then some partial clearing, hazy and mild. Highs 10-12 C by late afternoon and evening.

    TONIGHT ... Becoming windy (very windy Scotland with gusts to 120 km/hr) and staying mild in most regions, sharply colder after 0300h in Scotland. Showers or drizzle, but wintry showers in far north.

    MONDAY-TUESDAY ... Very windy with temperatures gradually falling in the south and central regions, and cold throughout in Scotland although with some variations as milder air rotates around the deep low tracking close to the Shetlands by Tuesday afternoon. Scotland may see blizzard like conditions at times with westerly winds 90-140 km/hr. Mixed wintry showers are likely further south with winds WNW 80-120 km/hr. Temperatures will generally be in the 3-5 C range but could fall to 0-2 C in snow showers. Heavy falls of snow are likely on higher ground in all regions and hail could be widespread at lower elevations.

    FURTHER OUTLOOK ... Britain will be very likely to see wintry conditions for several more days with heavy snow showers in eastern England and much of Scotland on strong northerly winds Wednesday, some areas of snow further west where streamers come inland from Irish Sea in NNW - NNE winds 60-100 km/hr, highs only 1-3 C, then in a general clearing trend but very cold, possibly some isolated heavy snowfalls as well as severe frosts to -7 C or lower, as the flow becomes increasing northerly to northeasterly. This severe cold could persist for quite some time. There will also be frequent snowfalls across northern France and most of western-central Europe during this cold spell, with travel disruptions likely to develop.


    Forecasts for North America

    Cold with some light snow from about Chicago to New York, amounts generally 3-5 cm but some heavier falls near Great Lakes. Highs -7 to -4 C. Cloudy and cold a bit further south, highs 2-5 C trending to sunshine and highs near 18 C in the southeast states, 22 C in New Orleans (site of Super Bowl although that's indoors in the Super Dome, perhaps Superman will show up too). That sunny, warm weather extends further west with some showers in southern California. Cold over the prairies but with slight moderation, as a mixture of snow and freezing drizzle pushes slowly east from southern Alberta. The blizzard in the eastern arctic has run its course as the low rapidly fills over the Davis Strait. That low has spun off the approaching low for the Ireland - U.K. forecasts.

    My local weather has been very foggy most of the past two days and just a slight clearing at mid-day allowed temperatures to recover a bit from the morning chill (3 C to 7 C). Current visibility is about a half kilometre with a ceiling of perhaps 200 feet (the local high rise buildings disappear into the fog at about the tenth storey level).


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