Your daily forecasts from Boards.ie weather forum (NO CHAT)

M.T. Cranium · 06-09-2012 7:28am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Thursday, 6 September, 2012
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Forecasts for Ireland

TODAY ... Mostly cloudy across parts of the north with a slight risk of drizzle in a few places, otherwise partly cloudy with sunny intervals developing and warming up to about 18-20 C in moderate southwest winds 15-25 mph (some higher gusts south coast).

TONIGHT ... Clear intervals, fog patches developing south, cloudy north with light rain or drizzle at times. Lows 9-12 C north, 6-9 C south.

FRIDAY ... Another relatively warm day with partly cloudy skies for most, highs about 19-21 C.

SATURDAY ... More cloud than sun except for a few locations in the southeast, some light rain at times in coastal northwest. Mild to warm again with morning lows 8-11 C and highs 19-21 C.

SUNDAY ... Increasing cloud with showers and risk of a thunderstorm developing, lows 7-10 C and highs 16-18 C.

MONDAY ... Windy and turning considerably cooler with showers including some hail and thunder, wind gusts to 50 mph from WSW veering NW later. Lows near 7 C and highs 14-17 C.

OUTLOOK ... Unsettled and somewhat milder again in stages, becoming more settled in the south mid-week but eventual outcome of both "Leslie" and "Michael" very much unresolved with a trend in most recent model runs to bring some kind of extratropical low back towards Ireland (there was a tendency for a while for the storm to travel further north). I think that the very slow motion of Leslie has made all of these forecast scenarios very speculative and we won't really know much about the actual outcome until beyond this weekend, after Leslie passes Bermuda, possibly as a cat-3 storm.

Forecasts for Britain

TODAY ... Cloudy with some sunny intervals, isolated brief showers mainly in west and north, somewhat heavier at times in western Scotland. Highs around 20-23 C (15-18 C in Scotland).

TONIGHT ... Hazy clear skies at first then fog developing, lows 7-10 C.

FRIDAY ... Partly cloudy, warm. Highs 22-25 C.

OUTLOOK ... Similar on Saturday then unsettled, becoming quite windy and turning colder.

Forecasts for North America

Little change as east remains unsettled in various regions, Leslie well offshore creating heavy swells along east coast. Warm and dry in western regions, but only as far north as about the US-Canada border, showery across most of inland western Canada although staying warm and dry on the coast. My local weather on Wednesday was once again sunny and rather warm with highs about 23 C.

M.T. Cranium · 07-09-2012 7:04am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Friday, 7 September, 2012
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Forecasts for Ireland

TODAY ... Mostly cloudy across parts of the north and west with a slight risk of showers, otherwise partly cloudy with sunny intervals developing and warming up to about 19-22 C in moderate southwest winds 15-25 mph (some higher gusts developing near west and north coasts).

TONIGHT ... Clear intervals, fog patches developing south, cloudy north with light rain or drizzle at times. Lows around 10-12 C north, 6-9 C south.

SATURDAY ... More cloud than sun except for a few locations in the southeast, some light rain at times in coastal northwest. Mild to warm again with morning lows 8-11 C and highs 19-21 C. Rainfalls only 2-5 mms at most and south/east likely to remain largely dry.

SUNDAY ... Increasing cloud with showers and risk of a thunderstorm developing, lows 7-10 C and highs 16-18 C. Rainfalls 10-20 mms likely.

MONDAY ... Windy and turning considerably cooler with showers including some hail and thunder, wind gusts to 45 mph from WSW veering NW later. Lows near 7 C and highs 14-17 C.

OUTLOOK ... Unsettled and somewhat milder again in stages, becoming more settled in the south mid-week but eventual outcome of both "Leslie" and "Michael" continues unresolved -- the early models are somewhat similar to their first approximations several days ago, of a strong low crossing the Atlantic, although now somewhat further north on the weekend of 15-16 September. The ECM model is now weakening both hurricanes around Newfoundland very rapidly but other disturbances form ahead of them in a gradually increasing westerly flow.

Forecasts for Britain

TODAY ... Partly cloudy with sunny intervals, isolated brief showers mainly in west and north-central (Cumbria in particular), highs around 21-24 C (16-19 C in Scotland).

TONIGHT ... Partly cloudy with fog patches, lows 7-10 C.

SATURDAY ... Partly cloudy, showers developing north and west by evening, warm. Highs 23-27 C.

OUTLOOK ... Becoming rather windy in the south on Sunday and Monday and very windy in parts of Scotland, considerably colder especially north and central, highs 13-16 C north and 16-19 C south.

Forecasts for North America

Hot and humid in southern states but turning cooler in central plains, Midwest with severe thunderstorms developing along a cold front. Cool and dry northern plains and parts of Canadian prairies, continuing very warm and dry in far west. Also rather hot in eastern states trending to near normal in Great Lakes region.

My local weather on Thursday was sunny and hot although with low humidity so the evening has cooled off reasonably quickly. The high was about 27 C.

M.T. Cranium · 08-09-2012 6:33am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Saturday, 8 September, 2012
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Forecasts for Ireland

TODAY ... A mostly cloudy start, then some brighter intervals, sunshine most likely near south coast and possibly east coast, meanwhile some light rain at times in coastal northwest. Rather warm again with higher humidity than recently, highs 19-22 C. Rainfalls only 2-5 mms at most and south/east likely to remain largely dry.

TONIGHT ... Rain setting in around the west coast, cloudy and misty elsewhere, mild. Lows 10-13 C.

SUNDAY ... Cloudy with showers and risk of a thunderstorm developing, a few brighter intervals mainly in the southern counties and highs 16-18 C. Rainfalls 10-20 mms likely, some heavier amounts possible.

MONDAY ... Windy and turning considerably cooler with showers including some hail and thunder, wind gusts to 45 mph from WSW veering NW later. Lows near 7 C and highs 14-17 C.

TUESDAY ... Continued rather cool and windy at times, periods of rain likely across the north, showers further south (could be largely dry in some south coast locations). Lows near 7 C and highs 13-16 C.

OUTLOOK ... Unsettled and somewhat milder again in stages, becoming more settled in the south mid-week but eventual outcome of both "Leslie" and "Michael" continues somewhat unresolved -- the consensus now looks like a combined extratropical low (as Leslie absorbs Michael) that becomes quite deep well to the north on the weekend of 15-16 September, but with the possibility of a more active secondary low for Ireland around 17-18th, or (as per the ECM model this morning) with the risk of strong winds back into the forecast at least in northern counties on the night of the 14th to 15th, from rapidly deepening low pressure well in advance of the tropical remnants -- these would follow as another disturbance around Monday-Tuesday 17th-18th. In the very long term, another spell of fine weather is indicated after that, to be followed by yet another tropical remnant later in the month. The main trend ahead, however, is cooling relative to the past week of warm weather.

Forecasts for Britain

TODAY ... Partly cloudy, warm and humid, showers developing north and west by evening, warm. Highs 23-27 C.

TONIGHT ... Cloudy, some isolated showers developing. Mild, lows 13-17 C.

SUNDAY ... Cloudy, showers and thunderstorms, highs near 20 C.

OUTLOOK ... Becoming rather windy in the south later Sunday and Monday and very windy in parts of Scotland, considerably colder especially north and central, highs 13-16 C north and 16-19 C south. The rest of the week closer to normal temperatures and somewhat unsettled south to very unsettled further north.

Forecasts for North America

Severe storms that developed earlier will continue overnight into Saturday across parts of the east and southeast, some will bring damaging wind gusts and large hail (most likely MS-AL-TN-NC-VA) and further north, heavy rains in parts of the inland northeast and eastern Great Lakes. This front is quite sharp and much cooler weather sets in rapidly once it passes (Tulsa OK dropped from 40 to 20 C earlier Friday). Highs in the low 20s are common in the central plains trending to 18-20 C further north, but it remains hot and dry to the west across the Rockies and west coast. This hot spell will come to a crashing end on Sunday into Monday with widespread showers and thunderstorms, but that front is still developing mainly offshore today.

My local weather on Friday was sunny and hot again, with low humidity and a high of about 31 C. Clear skies tonight and I hope to witness a rare "occultation" of Jupiter by the Moon that is timed for about 0300-0400h local time. It should be pleasantly warm despite the late hour.

M.T. Cranium · 09-09-2012 7:06am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Sunday, 9 September, 2012
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Forecasts for Ireland

"Leslie" has finally begun to move north and should be past Bermuda by tonight, then moving across southeast Newfoundland on Tuesday. The models are now finally converging on a solution not that different from their first approximation as discussed here a week ago, namely, a strong windstorm across northern regions late in the week. However, the timing now looks more like Thursday 13th. And the current expectation is that very strong winds will head more for northern Scotland although it seems likely to be quite gusty in exposed parts of Donegal, Mayo and other parts of the northwest.

TODAY ... Cloudy with a few brighter intervals, outbreaks of light to moderate rain, slight risk of thunder. Moderate southerly winds 20-30 mph at times with higher gusts towards evening in the southwest. Highs 16-18 C. Rainfalls generally 6-12 mm, potential for 20 mms in a few spots.

TONIGHT ... Showers ending, some clearing but clouding over again later, lows about 10 C in a moderate southwest wind.

MONDAY ... Variable cloud and frequent showers likely, some with hail and thunder, rather breezy but quite gusty at times in the far north (W 25-45 mph there, otherwise 15-30 mph). Highs 15-17 C. Rainfalls generally 5-10 mm.

TUESDAY ... Continuing windy and rather cool with frequent showers, winds WNW 20-40 mph, some higher gusts, lows near 8 C and highs near 15 C. Rainfalls generally 5-10 mm.

WEDNESDAY ... Breezy to windy, showers, possibly becoming very windy by evening and overnight. Lows near 8 C and highs near 18 C.

THURSDAY ... Windy, some severe gusts possible in north, showers rather squally at times. Lows near 9 C and highs near 16 C.

FRIDAY ... Breezy, partly cloudy, isolated showers. (could continue to be windy depending on actual timing of post-tropical Leslie/Michael remnants). Lows about 7 C and highs about 15 C.

OUTLOOK ... If this timing proves correct, the further outlook is likely to be more settled by the weekend. There is still some chance of a slower evolution of the unsettled and windy period, so confidence is not yet very high, but the weekend could turn out fairly pleasant in this scenario.

Forecasts for Britain

TODAY ... Increasing cloud, some showers developing, more steady rainfall in parts of Wales and Scotland. Highs 19-22 C.

TONIGHT ... Showers, becoming windy, SW 30-50 mph at times, lows 8-10 C.

MONDAY-TUESDAY ... Windy, unsettled, chilly especially Scotland. Highs only 14-17 C south and 10-13 C north.

OUTLOOK ... Very windy across Scotland and possibly parts of England and Wales by mid-week, as remnants of Leslie and Michael arrive. Gusts to 70 or 80 mph possible in exposed parts of north and west Scotland, otherwise, gusts to about 45-55 mph in exposed locations further south. Frequent showers.

Forecasts for North America

TODAY ... The very active front that hit New York and Washington earlier Saturday is now well offshore except in eastern Canada where it will stall and become wrapped up with oncoming Leslie (and Michael, which will probably weaken fast and slide into the whole mess somewhere near St John's Newfoundland on Tuesday). Otherwise, many parts of western-central North America hot and dry now, ahead of a series of weak fronts moving inland across British Columbia early today. Temperatures will be held down to 17-20 in B.C. with widespread showers that will feed some heavy storms late today in Alberta. Further east, highs of 30-35 C widespread in the Canadian prairies and northern-central plains, Rockies, trending to 40-43 C in parts of the southwest.

My local weather on Saturday was sunny (despite increasing high cloud) and continued hot with a high of 30 C. Feels fresher out now, the high cloud has become a weak front further east now and a stronger push of cool, marine air is just to the west now. Saw the lunar occultation of Jupiter event, the planet skimmed past the Moon's north pole around 0400h Saturday and at my latitude just failed to move behind the Moon as would have been seen further south in this time zone. Venus is still very bright and the Moon will move past around Wednesday morning here.

M.T. Cranium · 10-09-2012 7:12am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Moinday, 10 September, 2012
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Forecasts for Ireland

"Leslie" still on track to cross southeast Newfoundland on Tuesday. The guidance continues to suggest a glancing blow for northern parts of Ireland late Thursday, as the very strong winds will head more for northern Scotland early Friday. Would expect maximum wind gusts in Donegal around 55-60 mph from the current maps, Thursday evening or early Friday morning. Further south, would expect maximum gusts 40-50 mph. However this situation needs to be watched closely and there is still a slight risk of damaging wind gusts by Thursday.

TODAY ... Variable cloud and showers likely to become heavy by mid-day west, afternoon east, and some with hail and thunder, rather breezy but quite gusty at times in the far north (W 25-45 mph there, otherwise 15-30 mph). Highs 15-17 C. Rainfalls generally 7-15 mm.

TONIGHT ... Showers ending, breezy, cool. Winds westerly 20-40 mph at times, lows about 8 C.

TUESDAY ... Continuing windy and rather cool with frequent showers, winds WNW 20-40 mph, some higher gusts, and highs near 15 C. Rainfalls generally 5-10 mm. There could be some stronger gusts to about 50 mph in the northwest during the afternoon.

WEDNESDAY ... Breezy to windy, showers or periods of rain, possibly becoming very windy (SW 35-55 mph) by evening and overnight. Lows near 8 C and highs near 18 C.

THURSDAY ... Windy, turning quite warm across the south in brisk southwest winds, some sunshine inland and east coast, then later some severe gusts possible in north, showers developing late afternoon or evening and becoming rather squally at times. Lows near 9 C and highs near 16 C for northern counties but 19-21 C possible south.

FRIDAY ... Breezy, partly cloudy, isolated showers. (could continue to be windy depending on actual timing of post-tropical Leslie/Michael remnants). Lows about 7 C and highs about 15 C. Winds abating to moderate westerly by afternoon.

OUTLOOK ... The weekend looks more settled with some sunshine both days and highs around 18 C. Nights may be quite cool. The following week looks warm at first in a south to southeast backing flow, followed by the possibility of rain and wind from some form of tropical remnant low.

Forecasts for Britain

TODAY ... Windy, showers mostly western counties of England and Wales, highs near 17 C.

TONIGHT ... Showers, strong westerly winds especially Scotland, lows 7-10C.

TUESDAY ... Variable cloud, showers, risk of hail or thunder, chilly, strong westerly winds in Scotland and northern England (30-50 mph) trending to moderate further south (20-40 mph). Highs only 11-14 C north, 14-17 C south.

OUTLOOK ... Very windy across Scotland and possibly parts of England and Wales by mid-week, as remnants of Leslie arrive. Gusts to 70 or 80 mph possible in exposed parts of north and west Scotland on Friday morning, otherwise, gusts to about 45-55 mph in exposed locations further south. Frequent showers. Highs generally 13-15 C north and 17-21 C south although it could turn warmer on Thursday especially in the Midlands and south central England inland. (25 C possible).

Forecasts for North America

Hot, dry weather is now on the move east and will be centered today from about Manitoba south towards Texas with intensifying cold fronts moving east from the Rockies. Isolated severe storms are likely in regions from about Saskatchewan south to Colorado and Utah. Behind this front, western regions are turning much colder in gusty west winds with some showers or periods of rain and temperatures falling into the 12-15 C range. Despite this, severe forest fires have erupted in strong winds in south central B.C. and it is not clear whether sporadic showers will be enough to reduce this fire risk or if the winds will make things worse (the town of Peachland, B.C., is largely evacuated tonight). Meanwhile, eastern Canada is very wet as a front stalls to await the arrival of Leslie late tonight (Tuesday morning) in eastern Newfoundland. Some wind gusts to 70 mph are expected in the Avalon peninsula.

My local weather on Sunday was cloudy and much cooler than previous days at about 17 C. Light rain has begun to fall this evening. (still very dry ground here too, although no danger of fires locally).

M.T. Cranium · 11-09-2012 7:19am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Tuesday, 11 September, 2012
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Forecasts for Ireland

"Leslie" is now approaching the south central coast of Newfoundland and will be close to the south tip of Greenland by tonight. The guidance continues to suggest a glancing blow for northern parts of Ireland late Thursday, as the very strong winds will head more for northern Scotland early Friday. I continue to expect maximum wind gusts in Donegal around 55-60 mph from the current maps, Thursday evening or early Friday morning. Further south, would expect maximum gusts 40-50 mph. However, still on alert as this situation needs to be watched closely and there is still a slight risk of damaging wind gusts by Thursday.

TODAY ... Continuing windy and rather cool with frequent showers, a few with hail and thunder, and winds WNW 20-40 mph, some higher gusts near west coast to 50 mph, and highs near 15 C. Rainfalls generally 5-10 mm.

TONIGHT ... Mostly cloudy, breezy and cool, a few showers and lows 6-8 C.

WEDNESDAY ... Breezy to windy (SW veering WNW 20-40 mph), showers or periods of rain, possibly becoming very windy (W 35-55 mph) by evening and overnight. Highs near 18 C. Rainfalls 10-15 mms.

THURSDAY ... Windy, turning quite warm across the south in brisk southwest winds, some sunshine inland and east coast, then later some severe gusts possible in north, showers developing late afternoon or evening and becoming rather squally at times. Lows near 9 C and highs near 16 C for northern counties but 19-21 C possible south. Strongest winds likely around 6-9 p.m.

FRIDAY ... Breezy, partly cloudy, isolated showers. Lows about 7 C and highs about 15 C. Winds abating to moderate westerly by afternoon.

OUTLOOK ... The weekend looks more settled with some sunshine both days and highs around 18 C. Nights may be quite cool. The following week looks warm at first in a south to southeast backing flow, followed by the possibility of showers from some remnant of the energy from "Michael" which now appears as though it may meander well clear of "Leslie" and feed into a trough picking up a low near the Azores, while the next tropical system, likely to be named soon "Nadine" moves northwest more towards Newfoundland.

Forecasts for Britain

TODAY ... Variable cloud, showers, risk of hail or thunder, chilly, strong westerly winds in Scotland and northern England (30-50 mph) trending to moderate further south (20-40 mph). Highs only 11-14 C north, 14-17 C south. Some isolated severe storms possible.

TONIGHT ... Cloudy, showers or periods of rain developing, cool. Lows 7-10 C.

OUTLOOK ... Very windy across Scotland and possibly parts of England and Wales by Thursday night, as remnants of Leslie arrive. Gusts to 70 or 80 mph possible in exposed parts of north and west Scotland on Friday morning, otherwise, gusts to about 45-55 mph in exposed locations further south. Frequent showers. Highs generally 13-15 C north and 17-21 C south although it could turn warmer on Thursday especially in the Midlands and south central England inland. (25 C possible). A warm spell likely from weekend to mid-week then showery.

Forecasts for North America

Warm and dry across much of the central and eastern U.S. and adjacent southern Canada, as a cold front begins to lose steam across the northern plains states and stalls out in the southwest. Pacific northwest states and western Canada windy and cool with showers mostly over higher terrain. Apart from a few isolated storms along this front, much of the "lower 48" states will remain dry. Windy and wet in far eastern Canada especially Newfoundland as "Leslie" moves through, 50-150 mms rain likely.

My local weather on Monday was partly cloudy becoming sunny, with showers mainly over surrounding peaks. It was quite cool compared to last week with highs only 15-17 C and a moderate to strong west wind.

M.T. Cranium · 12-09-2012 7:32am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Wednesday, 12 September, 2012
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Forecasts for Ireland

Previous outlook on "Leslie" unchanged. Storm moved rapidly through Newfoundland around mid-day and is now southeast of Greenland heading for south coast of Iceland. It appears more certain now that northern Scotland will see the greatest impact from its winds, while Donegal and other parts of the north will get a more glancing blow on Thursday night.

TODAY ... Some rain across Ulster this morning spreading south but parts of the west may remain dry although cloudy, then becoming partly cloudy with isolated showers, rather gusty winds at times veering to NW 20-40 mph, and highs 12-15 C north, 15-18 C south. Rainfalls generally 2-5 mms, possibly heavier in east Ulster and north Leinster (10 mms).

TONIGHT ... Clear intervals, chilly to start but clouding over around midnight to early morning, and turning milder. Early lows 6-9 C then about 10-13 C.

THURSDAY ... Cloudy periods, drizzle, partial clearing and warm, humid especially across southern and central counties, winds increasing gradually to reach SW 30-50 mph by late afternoon (40-60 mph north). Highs will reach about 21 C in parts of southeast, 17-19 C most other places, 15-17 C north.

THURSDAY NIGHT ... Remnants of Leslie will brush past the north coast and could produce a few gusts to 65 mph from a westerly direction, with a band of moderate rain making some slight advance south but tending to fragment before reaching most of central Ireland. Winds will peak about 35-49 mph in gusts further south. Overnight lows 12-14 C.

FRIDAY ... Variable cloud, one or two showers, breezy to windy, WNW 20-40 mph (higher gusts north), highs 15-17 C.

SATURDAY ... Sunny intervals, warmer again, morning lows 6-9 C and afternoon highs 19-22 C.

SUNDAY ... Showers, chance of a thunderstorm, breezy, highs near 17 C.

OUTLOOK ... Another settled interval should develop during the week, outcome of new tropical storm Nadine quite uncertain but not likely to affect Ireland before late next week, if at all.

Forecasts for Britain

TODAY ... Showers, some heavy in west and north-central portions, chilly in Scotland (highs only 12-15 C), otherwise cool (highs 15-17 C).

TONIGHT ... Showers ending, some clearing, chilly. Lows near 7 C on average.

THURSDAY ... Partly cloudy, increasing southwest winds, becoming quite stormy late afternoon or evening in Scotland where gusts could reach 75 mph or higher around midnight. Warm in south by afternoon. Highs 19-22 C south to 14-17 C north.

FRIDAY ... Breezy to windy (strong gusts Scotland during the morning), showers but also some clear intervals, winds W 30-50 mph. Highs 17-20 C.

OUTLOOK ... See Ireland forecast, similar if slightly slower evolution.

North American forecasts

Dry and warm weather continuing in central and some eastern regions, highs around 27-30 C. Windy and cool in western Canada and adjacent northern plains states, highs 14-17 C. Some showers along weak front through western Great Lakes and Midwest.

My local weather on Tuesday was partly cloudy with plenty of sunshine by afternoon, but rather chilly in moderate westerly winds, highs 14-16 C.

M.T. Cranium · 13-09-2012 7:27am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Thursday, 13 September, 2012
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Forecasts for Ireland

ALERT for risk of wind gusts in excess of 50 mph across northern regions, mainly this evening and overnight. The energy from "Michael" has blended into the cloud mass associated with former TS "Leslie" and the combined energy just might be enough to get wind speeds into the 35-55 mph range in some parts of Ulster and Connacht. We are watching closely to monitor the very small risk of more damaging gusts that seem more likely headed for Scotland (where damage probably won't occur in the regions impacted, everything there is built for stronger winds than they will see from this event).

TODAY ... Cloudy periods, some local drizzle west and north coasts mainly, partial clearing developing south-central especially inland to east coast, and becoming warm, humid especially across southern and central counties, winds increasing gradually to reach SW 30-50 mph by late afternoon (40-60 mph north). Highs will reach about 21 C in parts of southeast amd possibly 23 C south of Dublin where the downsloping factor may boost readings, 17-19 C most other places, but only 15-17 C north.

THURSDAY NIGHT ... Remnants of Leslie will brush past the north coast and could produce a few gusts to 65 mph from a westerly direction, with a band of moderate rain making some slight advance south but tending to fragment to scattered showers before reaching most of central Ireland. Some southern locations will remain dry, otherwise, 3-7 mms rain on average. Winds will peak about 35-49 mph in gusts further south. Overnight lows 12-14 C.

FRIDAY ... Variable cloud, one or two showers, breezy to windy, WNW 20-40 mph (higher gusts north), highs 15-17 C. Some longer sunny intervals seem likely to develop in the south and perhaps also in the east.

SATURDAY ... Sunny intervals, warmer again, morning lows 6-9 C and afternoon highs 19-22 C. Cloud, drizzle and sea fog may impact some northern and northwestern coastal districts.

SUNDAY ... Partly cloudy to overcast, with showers, chance of a thunderstorm, breezy, lows 10-12 C and highs near 17 C. Winds WSW 30-50 mph.

MONDAY-TUESDAY ... Cool and breezy in a west to northwest flow of 20-35 mph, showers at times, highs only 14-17 C.

OUTLOOK ... Another settled interval should develop later during the week but there could be some near frosts or even ground frosts before a milder period, meanwhile, the outcome of new tropical storm Nadine is still quite uncertain but not likely to affect Ireland before late next week, if at all. Models do show a fairly wet period resulting but it's too far out to be very confident that this solution is even approximately correct given the variables in play.

Forecasts for Britain

TODAY ... Partly cloudy, increasing southwest winds, becoming quite stormy late afternoon or evening in Scotland where gusts could reach 75 mph or higher around midnight. Warm in south by afternoon. Highs 19-22 C south to 14-17 C north. Strong winds will only arrive in south well after sunset.

TONIGHT ... Windy with showers or periods of rain heavier in Scotland, northern England where 10-20 mms possible, lows 8-12 C.

FRIDAY ... Breezy to windy (strong gusts Scotland during the morning), showers but also some clear intervals, winds W 30-50 mph. Highs 17-20 C.

OUTLOOK ... See Ireland forecast, similar if slightly slower evolution.

North American forecasts

Dry and warm weather now moving into the east ahead of a slowly developing frontal trough that will bring more organized rainfalls to parts of Great Lakes, Midwest and central plains. Heavier rains at times spreading north from Gulf, but east coast largely dry and sunny. West coast now warming under high pressure, with cool windy conditions inland west and Canadian prairies.

My local weather on Wednesday was sunny and while quite chilly to start, the afternoon was relatively warm at 22 C.

M.T. Cranium · 14-09-2012 7:48am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Friday, 14 September, 2012
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Forecasts for Ireland

TODAY ... Continued windy until mid-afternoon then calming down gradually with WNW winds generally 25-45 mph and some higher gusts possible, isolated showers although not much accumulation (1-3 mm) and some sunny intervals becoming longer by late afternoon especially in southern counties. Highs about 14 C north to 17 C south.

TONIGHT ... Clear intervals, breeze dying down further especially inland south where some fog patches could develop. Chilly with lows 7-10 C north and possibly 4-7 C inland south, 6-8 C coastal.

SATURDAY ... Sunny intervals for most, pleasant with highs 16-19 C. More cloud likely in far north with some mist or drizzle near Atlantic in some parts of northwest. Breezy again by afternoon (WSW 15-30 mph).

SUNDAY ... Cloudy with periods of rain developing, 5-10 mms on average, some afternoon sunny breaks or brighter intervals developing, winds veering to west 20-35 mph, morning lows 9-12 C and afternoon highs 15-17 C.

MONDAY and TUESDAY ... Variable cloud, breezy, rather cool, winds generally westerly at about 15-30 mph, a few showers but rainfalls only about 3-7 mms on average, highs near 15 C.

WEDNESDAY ... Windy and cool with showers, lows near 7 C and highs near 14 C, winds NW 30-50 mph.

OUTLOOK ... Becoming dry and cool with slight risk of frosts developing, daily highs in the range of 12 to 16 C. The latest guidance on Nadine once again backs off moving this storm east and in fact most models now show it drifting north or north-north-west in the general direction of Greenland. The ECM still has Nadine tracking east for a time in the Azores but then shoves it back to the west roughly towards its point of origin. Instead of the tropical low, more locally sourced low pressure seems likely to deepen over the North Sea by late next week into the following weekend, with the higher pressure blocking the flow around 20 W, keeping Ireland in a rather cool northwest flow. This cannot be regarded as a final outcome yet but the ECM track for Nadine is a well-known subset of central Atlantic storms and a track from that starting point towards Ireland would be much less likely in statistical terms.

Forecasts for Britain

TODAY ... Windy with showers, (W 40-60 mph at times) and cooler, temperatures steady 13-15 C.

TONIGHT ... Breezy with showers ending, some clearing in south by morning, chilly, lows 7-10 C for most, 5-8 C some inland central locations.

SATURDAY ... Pleasant sunshine in south, highs near 17 C. Cloudy north, outbreaks of light rain or drizzle, highs near 15 C.

OUTLOOK ... Similar to Ireland as per the above forecast for Ireland.

Forecasts for North America

The pleasant, warm and dry spell continues east of a line from about Montreal to Pittsburgh to Cincinnati, with a front slowly advancing across the Great Lakes and Midwest bringing some heavy showers, and a more organized area of heavy rainfalls in Arkansas moving towards Tennessee and northern Mississippi, Alabama and Georgia. Hot and humid south of that disturbance with isolated storms. Windy and cool in some north central states and much of inland western Canada, trending to warm and dry on the west coast with rain moving into central B.C. from the Pacific but heading east rather than south. Highs on the west coast near 24 C.

My local weather on Thursday was basically a perfect late summer or early autumn day, after a bracing start (7-10 C) the high was about 24 C. Light winds made that feel rather hot in the direct sun but it stayed cool in the shade. It remains very dry and the risk of wildfires has not reduced much. We are also seeing a lot of bears coming into urban areas looking for fruit as the bush has not produced a very good crop of berries for them. In fact there was a bear captured today not far from where I live which is quite unusual (that sentence could use editing but too late now).

M.T. Cranium · 15-09-2012 7:23am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Saturday, 15 September, 2012
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Astronomy note: New moon occurs tonight at 03:12 a.m. Sunday (IST).

Forecasts for Ireland

TODAY ... Sunny intervals for most, pleasant with highs 16-19 C. More cloud likely in far north with some mist or drizzle near Atlantic in some parts of northwest. Breezy again by afternoon (WSW 15-30 mph).

TONIGHT ... Cloudy with rain spreading rapidly across the country from west to east, about 5-10 mm likely. Moderate southwest winds and lows 9-12 C.

SUNDAY ... Cloudy with periods of rain heaviest morning to mid-day in Leinster, then partly cloudy, a further 5-10 mms on average in eastern counties, some afternoon sunny breaks or brighter intervals developing, but isolated showers mainly in Connacht, west Ulster, with winds veering to west 20-35 mph, and afternoon highs 15-17 C.

MONDAY ... Variable cloud, breezy, rather cool, winds generally westerly at about 20-40 mph, a few showers but rainfalls only about 3-7 mms on average, morning lows 5-8 C and highs near 15 C.

TUESDAY ... Partly cloudy, showers, cool. Lows 5-8 C and highs near 15 C. Winds WNW 25-45 mph.

WEDNESDAY ... Breezy and cool with morning showers, afternoon sunny intervals, lows near 7 C and highs near 15 C, winds NW 20-40 mph.

THURSDAY-FRIDAY ... Partly cloudy and cool, risk of ground frosts inland, daytime highs near 14 C.

OUTLOOK ... Unsettled, cool. Models are still showing "Nadine" meandering around near the Azores for several days although the GFS now wants to bring a remnant low into the Biscay region before the end of the month.

Forecasts for Britain

TODAY ... A few morning showers in east clearing, with pleasant sunshine in south and west including Wales, highs near 17 C. Cloudy north, outbreaks of light rain or drizzle, highs near 15 C.

TONIGHT ... Increasing cloud, rain arriving west and north. Lows 10-13 C.

SUNDAY ... Showers and risk of a thunderstorm. Highs near 17 C on average.

OUTLOOK ... Similar to Ireland as per the above forecast for Ireland.

Forecasts for North America

Showers or periods of rain moving through the northeast states with a clearing and cool trend for Great Lakes and Midwest. The weather gradually warms across the central U.S. towards the Rockies and west coast, but a secondary cold front is bringing even cooler weather to the eastern half of the Canadian prairies, with Alberta near normal and B.C. warm in a subtropical high pressure pattern (large diurnal ranges outside the major cities).

My local weather on Friday continued excellent with sunshine and a high of about 25 C, as high cloud spread in from a distant front well to our north. This should dissipate but we could see some morning low cloud before the warm spell resumes later Saturday. Expecting 28 C on Sunday.

M.T. Cranium · 16-09-2012 6:48am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Sunday, 16 September, 2012
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Forecasts for Ireland

TODAY ... Cloudy with periods of rain heaviest morning to mid-day in Leinster, then becoming partly cloudy, a further 5-10 mms on average in eastern counties, 2-4 mm further west from later showers ... some afternoon sunny breaks or brighter intervals developing, but isolated afternoon showers mainly in Connacht, west Ulster, with winds veering to west 20-35 mph, and afternoon highs 15-17 C.

TONIGHT ... Mostly cloudy, some clear intervals south after midnight, lows between 6 and 10 C. Moderate SW to W winds in some more exposed locations.

MONDAY ... Variable cloud, breezy, rather cool, winds generally westerly at about 20-40 mph, a few showers but rainfalls only about 3-7 mms on average, and highs near 15 C.

TUESDAY ... Partly cloudy, showers, cool. Lows 5-8 C and highs near 15 C. Winds WNW 25-45 mph.

WEDNESDAY ... Breezy and cool with morning showers, afternoon sunny intervals, lows near 7 C and highs near 15 C, winds NW 20-40 mph.

THURSDAY-FRIDAY ... Partly cloudy and cool, risk of ground frosts inland, daytime highs near 14 C.

OUTLOOK ... Unsettled, cool. Models are still showing "Nadine" meandering around near the Azores for several days, and now the GFS shows the storm looping all the way around to near Newfoundland then a weak remnant heads east by the first of October.

Forecasts for Britain

TODAY ... Showers and risk of a thunderstorm. Highs near 17 C on average. Rainfalls 10-20 mms and heavier falls likely in western districts.

TONIGHT ... Showers ending, some clearing, cool. Lows 6-9 C.

MONDAY to WEDNESDAY ... Showery, breezy, somewhat cooler than normal with highs around 15-18 C. More settled by late in the week with the risk of slight frosts in rural sections.

Forecasts for North America

Showers or periods of rain moving out of the northeast states with a clearing and cool trend to follow, continuing partly cloudy and cool for Great Lakes and Midwest with a few scattered showers. The weather gradually warms across the central U.S. towards the Rockies and west coast, but a secondary cold front is now bringing even cooler weather to the northern plains states and it remains rather chilly across the eastern half of the Canadian prairies, with Alberta near normal and B.C. warm in a subtropical high pressure pattern (large diurnal ranges outside the major cities).

My local weather on Saturday continued sunny with sunshine and a high of about 24 C, expecting 28 C later today, and warm/dry most of this coming week.

New moon was at 0312h IST.

M.T. Cranium · 17-09-2012 7:36am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Monday, 17 September, 2012
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Forecasts for Ireland

TODAY ... Partly to mostly cloudy with a few light showers, then a band of heavier showers affecting Connacht and west Ulster mid-day, some remnants of these heavier showers may reach other districts later. Rainfalls generally about 2-5 mm but could reach 5-10 mm in the northwest. Rather breezy at times with winds WSW 20-35 mph. Highs 13-16 C north, west and 15-18 C south, east.

TONIGHT ... Cloudy with a few clear breaks, showers dying out, lows about 7 or 8 C in moderate WNW breezes 15-25 mph.

TUESDAY ... Breezy and cool, winds NW 20-40 mph, occasional showers or longer periods of rain in some western counties, rainfalls 5-10 mm, and highs about 14-16 C.

WEDNESDAY ... Variable cloud, some longer bright or sunny intervals developing, showers becoming confined to north then dying out but a secondary band of light rain possible in the northwest late in the day. Morning lows 3-7 C and highs 14-17 C. Isolated ground frost possible.

THURSDAY ... Cloudy with some sunny intervals, chilly. Morning lows in rural areas only 2-5 C and about 5-8 C elsewhere, highs 13-15 C. Light to moderate northerly winds developing.

FRIDAY ... Mostly dry but considerable cloudiness, morning ground frosts with lows about 2-5 C and highs 13-15 C.

OUTLOOK ... Becoming unsettled again, rather cool in a northwest flow, highs about 12-14 C. The current indications are that "Nadine" will circle around once it reaches the eastern Azores later this week, heading away from Europe and back towards the south-central Atlantic, then north into the regions east of Newfoundland. A weak remnant of this storm could be a factor in Irish weather in about two weeks' time. However, there is a very slight chance of a different path that brings Nadine into the Biscay region in about a week. The UK model is currently hinting at this but most of the other global models are on the other plan mentioned.

Forecasts for Britain

TODAY ... Partly cloudy south, highs near 18 C. Showers central and north, breezy, cool, highs near 15 C.

TONIGHT ... Showers at times, lows 7-9 C.

TUESDAY ... Breezy to windy, cool, frequent showers. Highs 12-15 C north and 15-18 C south. Winds WNW 30-50 mph in exposed locations.

OUTLOOK ... Similar to Ireland as per the above forecast, although Wednesday could remain showery in the east all day.

Forecasts for North America

TODAY ... Heavy showers and thunderstorms are developing from the central and western Great Lakes to the Gulf of Mexico, with warm and dry weather near 30 C on the east coast until some time tomorrow when this front arrives. Chilly in north central states and most of the Canadian prairies, highs only 13-15 C. Warm to hot and dry on the west coast and inland to about the crest of the Rockies, highs 24-27 C.

My local weather on Sunday was sunny and very warm with a high near 25 C.

M.T. Cranium · 18-09-2012 7:18am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Tuesday, 18 September, 2012
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Forecasts for Ireland

TODAY ... Breezy and cool with frequent showers in the west, and occasional showers further east. Slight risk of thunder and small hail, winds NW 20-40 mph and highs only 13-15 C north, 15-17 C south. Rainfalls 5-10 mm.

TONIGHT ... Partly cloudy, showers dying out, chilly. Lows 3-7 C in rural areas with slight risk of ground frost, otherwise 6-10 C.

WEDNESDAY ... Mostly cloudy, showers tending to move east with partial clearing in south but a secondary area of rain will then move into Connacht and west Ulster later in the day. Winds backing to SW 10-20 mph, a little milder in the south, with highs reaching 16-18 C there, but staying cool in the north (13-15 C). Rainfalls about 2-5 mm south to 5-15 mm north.

THURSDAY ... Rain ending around mid-morning west, afternoon east, although amounts across the south slight as most of this system will be north of a line from Galway to Dublin. Rainfalls of about 7-15 mm possible there. Morning lows about 5-8 C and afternoon highs 13-16 C for most, 16-18 C south.

FRIDAY ... Partly cloudy, a chilly start with isolated frost, lows 2-5 C, then afternoon highs only 12-15 C.

SATURDAY ... Partly cloudy to overcast, showers developing west, morning lows about 3 C and afternoon highs about 15 C.

SUNDAY ... Showers or periods of rain, highs 13-16 C.

OUTLOOK ... The general theme will be cool and unsettled. Some models are now returning to the idea of "Nadine" eventually heading northeast into Biscay as a weak extratropical low but presumably with rather heavy rainfalls possibly extending into eastern Ireland, so this will need to be watched, although at the same time other model solutions continue to take remnants of Nadine back to the west before any northward drift resumes. The later European model shows Nadine failing to progress past the Azores but another non-tropical low forming in Biscay that otherwise looks similar to the solutions I mentioned, so either way the rest of the signals favour cool and unsettled weather through the last week of the month with the possibility of heavier rainfalls returning.

Forecasts for Britain

TODAY ... Variable cloud, showers heavier in west and north, breezy south to windy north (NW 30-50 mph in Scotland) ... highs around 12-14 C north and 15-18 C south.

TONIGHT ... Partly cloudy, isolated showers, breezy, cool. Lows 4-7 C on average, some isolated ground frost possible well inland.

OUTLOOK ... Similar pattern to the above forecast for Ireland with a brief dry spell around Friday-Saturday then cool and unsettled again by next week. If Nadine were to follow the Biscay track some parts of southern England could get a soaking downpour of 20-50 mm.

Forecasts for North America

TODAY ... Heavy showers and thunderstorms moving through the Great Lakes and inland northeast, Mid-Atlantic states and inland southeast, and turning considerably cooler than yesterday with highs only 15-20 C (to 23 C south). Some parts of coastal northeast and New England a bit warmer with this front arriving this evening there. Warm to hot and dry in western regions, but remaining cool in a northerly flow in eastern prairies and northern plains states.

My local weather on Monday was sunny and very warm, or even hot, with a high about 26-28 C (trending warmer inland, 22 C at the seafront).

M.T. Cranium · 19-09-2012 7:30am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Wednesday, 19 September, 2012
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Forecasts for Ireland

TODAY ... Mostly cloudy, showers tending to move east with partial clearing in south but a secondary area of rain will then move into Connacht and west Ulster later in the day. Winds backing to SW 10-20 mph, a little milder in the south, with highs reaching 16-18 C there, but staying cool in the north, highs about 13-15 C. Rainfalls about 2-5 mm south to 5-15 mm north.

TONIGHT ... Rain, heavy at times moving across northern and some central counties (mostly north of a Galway-Dublin line), 10-15 mm in places, more showery further south, some places could remain dry although misty. Lows will thus be warmer in the north (7-11 C) and coolest inland south (3-7 C) but also rather mild around the coasts. Rainfalls in the south only trace to about 3 mms.

THURSDAY ... Rain ending around mid-morning (north)west, afternoon east (including much of Leinster), although amounts across the south especially southwest, slight, as most of this system will continue to be north of a line from Galway to Dublin (possibly more like Athlone to Wicklow by mid-day through afternoon). Rainfalls of about 7-15 mm possible in Ulster, trending to trace amounts in southwest. Afternoon highs 13-16 C for most, 16-18 C south. On Thursday night the rain will be fragmenting to light showers and the southeast will be under what remains with 2-4 mm amounts.

FRIDAY ... Any remnant rain or drizzle in southeast clearing, otherwise partly cloudy skies developing from north to south, a chilly start with isolated frost in north-central counties, lows 0-5 C, but held up to 5-8 C by cloud in the southeast, followed by afternoon highs only 12-15 C in all areas. Winds rather light but a trend towards northerly breezes then calm at night.

SATURDAY ... Partly cloudy to overcast, showers may be developing west (see Sunday discussion), morning lows about 3 C and afternoon highs about 15 C.

SUNDAY ... Showers or periods of rain may develop with highs 13-16 C. This weather system is challenging the various global models so bear in mind that it could turn out rather fragmented and weak, or on the other hand well-organized with moderate or even heavy rainfalls. With "Nadine" likely to become trapped near the Azores or even backing away to the south, the most likely outcome is a separate low, forming not far to the northeast of Nadine, then moving up through Biscay on Saturday night towards the Irish Sea or southern England. This situation will remain rather uncertain until perhaps Friday. The latest European model as well as the GFS have weakened or dropped this system but it is still on the GEM and UK models. If the system fails to materialize the weather may be relatively dry with just weak fronts pushing across from the west rather than moisture from the south.

The outcome for "Nadine" is also quite different on the various models. The GFS takes it on a long meandering path around Portugal next week and it only dies out totally in about ten days. Other models show it moving back to the southwest and back into the subtropical central Atlantic well to the southwest of the Azores again.

OUTLOOK ... The following week looks rather cool and unsettled at first, but a less showery trend will develop mid-week with higher pressure edging into the picture, temperatures 1-3 degrees below normal values. This would imply a return of scattered frosts well inland.

Forecasts for Britain

TODAY ... Partly cloudy and cool, some southern counties largely dry but Wales and central England showery, then further north a few intervals of light rain. Highs only 12-15 C north, to 16-19 C south.

TONIGHT ... Partly cloudy, some clear intervals, local frost south central inland, remaining cloudier north with intervals of rain spreading in from Ulster. Lows 2-6 C inland south, 7-10 C elsewhere.

OUTLOOK ... Similar pattern to the above forecast for Ireland with a brief dry spell around Friday-Saturday then cool and unsettled again by next week. If Nadine or any other low were to follow the Biscay track into south central England on Sunday, some parts of southern England could get a soaking downpour of 20-40 mm. This heavy rain will spread north into Scotland by Sunday night or Monday but it will remain showery in the south in chilly northwest winds.

Forecasts for North America

TODAY ... Heavy showers and thunderstorms moving out of the Great Lakes and northeast, Mid-Atlantic states by morning but remaining to some extent stalled over the southeast, while spreading into New England and parts of eastern Canada. A weak high will spread partly cloudy to sunny weather into regions vacated by the rain, but this will last only one day before a secondary low arrives from Minnesota where it will be turning cooler again during the day with a second push of chilly air moving south. This covers most of western Canada east of the Rockies and the northern plains states, but it remains warm to hot and dry in the far west.

My local weather on Tuesday was once again sunny and very warm, or even hot, with a high about 25-27 C (trending warmer inland, 20 C at the seafront in a rather strong sea breeze). Despite this heat the nights are quite cool, it had already fallen to 15 C at 10:30 pm here.

M.T. Cranium · 19-09-2012 9:22pm

UPDATE _ Wed 19 Sep 2012 _ 9:20 p.m.
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The European model output is now showing a severe storm potential for Ireland on Sunday or Monday into Tuesday, from the Biscay-origin low pressure system (not "Nadine") discussed earlier in the forecast. The timing is perhaps as uncertain as the intensity so would caution not to focus on either too much at this early stage. The main feature is that strong surface low pressure rapidly phases in with developing upper level low pressure that drops southeast to cause the system to loop around during a deepening process (according to the European model).

At this early stage, we are not convinced of the severity of this outcome but want to draw attention to the potential as we are now five days away from the event.

The depicted storm would travel rapidly northeast on Sunday night and Monday across Britain and then swerve northwest towards Ulster, then would loop around back to the south on Tuesday. During its deepening phase, as depicted in the model run, this could be expected to draw in strong gale force winds from the southwest especially in southern coastal sections, and heavy rainfalls throughout Ireland (30-50 mms). From the maps at present I would estimate maximum wind potential of about 80-110 km/hr or 50-65 mph in the south coastal regions trending down to 30-50 mph further north (where the pressure gradient is slacker during the deepening phases). Most of these impacts would be Monday night according to the new timing.

Other models are not totally inconsistent with this scenario and as the European model leads in general on verification, I would advise a close watch on developments. Nadine, meanwhile, has been generally pushed away to the southwest on most model runs today, after interacting with this Biscay storm in its early stages Friday night.

Just a rough "ball-park estimate" of the probability of this severe wind and rain event -- about 30 to 40 per cent at this stage, with another 30 to 40 per cent for a modified rain and wind outcome and 10 to 30 per cent for a less stormy or dry outcome.

M.T. Cranium · 20-09-2012 6:48am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Thursday, 20 September, 2012
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ADVANCE ALERT for possible heavy rain and strong winds by Monday covering large parts of the country. Details are still somewhat sketchy but model consensus is increasing, and a looping track will bring these effects to most regions at various times. This storm is not "Nadine" which now seems more likely to stall over the Azores and then back away to the south or southwest, but the storm expected in Ireland breaks away from Nadine's cloud mass later today or Friday morning, and in any case will become about as strong as Nadine might be on a similar track. Watch for updates as we get closer to this event on Monday. The system has slowed down somewhat from yesterday's early forecast and this will leave more of the weekend dry although first effects of the system will be felt later Sunday. ... Each global model has a slight variation on the theme of this storm system looping around and the UKMO does not bring it as far north which would leave Ireland in northeast winds throughout, whereas the ECM makes a wider loop that would be reflected in stronger winds from a southwest direction at some point. The other models are somewhat intermediate. This situation will be interesting to follow but the chances of a severe storm event are rising to the 50-50 range now, at least for some coastal regions.

Forecasts for Ireland

TODAY ... Rain gradually ending across the north-west, and tapering off to drizzle by afternoon in central, east and northeast (including much of Leinster), although amounts across the south especially southwest, slight, as most of this system will continue to be north of a line from Galway to Dublin (possibly more like Athlone to Wicklow by mid-day through afternoon). Rainfalls of about 7-15 mm possible in Ulster, trending to trace amounts in southwest. Afternoon highs 13-16 C for most, 16-18 C south.

TONIGHT ... Rain will be slowly fragmenting to light showers and drizzle and the southeast will be under the last remnants with 2-4 mm amounts, trace amounts elsewhere, and some clearing late in Ulster, leading to patchy ground frost. Lows 3-7 C north to 7-10 C south.

FRIDAY ... Any remnant rain or drizzle in southeast clearing, otherwise partly cloudy skies developing from north to south, a chilly start with isolated frost in north-central counties, some sunny breaks mid-day and afternoon with highs only 12-15 C in all areas. Winds rather light but a trend towards northerly breezes then calm at night.

SATURDAY ... Partly cloudy with some good sunny intervals possible before becoming more overcast, showers possible near west coast by evening ... morning lows about 2-6 C with scattered ground frost, and afternoon highs about 15-17 C.

SUNDAY ... The morning may be dry for most of the north and west, with drizzle moving into the southeast. Cold to start with frosts in Ulster and Connacht inland, lows -1 to +4 C, but 5-8 C southeast. Increasing cloud with showers or periods of rain by evening, 5-10 mms possible, and highs 13-16 C. Winds generally light at first then increasing to E-NE 20-40 mph.

MONDAY ... Periods of rain and moderate or even strong winds developing as low pressure loops around from Britain and across western counties by Monday night. Rainfalls 20-40 mms possible, lows near 8 C and highs 12-15 C, with cyclonic winds tending to increase more dramatically at a distance from the low centre where winds could be quite slack. As the track is not that certain, the best idea at present is to alert all districts to some potential for strong winds, but more likely NE winds in the north and SW winds in the south around this low. Some model depictions suggest potential for wind gusts above 50 mph.

TUESDAY ... Variable cloud, showers or periods of light rain, NE to N winds of about 20-30 mph, chilly with lows near 7 C and highs 10-13 C.

OUTLOOK ... Slow improvements but rather unsettled and cool for several more days, eventually the possibility of frosts returning.

Forecasts for Britain

TODAY ... Cloudy for most, some brighter intervals south, frequent showers central and occasional light showers south. Highs 14-17 C. Turning quite chilly by afternoon or evening in Scotland, temperatures falling to 6-9 C by evening.

TONIGHT ... Partial clearing north, frosts developing, lows -2 to +3 C inland Scotland and north-central England. Cloudy further south, light rain or drizzle, lows 5-8 C. Misty south, lows 8-10 C.

FRIDAY ... Showers moving further south, partial clearing across north-central regions, cool. Highs 12-15 C north to 15-17 C south.

SATURDAY ... Sunny intervals, morning frosts possible, fog patches. Highs about 15-18 C south. Further north, highs 13-16 C.

SUNDAY-MONDAY ... Stormy at times with heavy rainfalls, strong east winds becoming more northeast then swirling around to west or southwest. Temperatures steady 12-14 C and rainfalls 30-40 mms in many places.

OUTLOOK ... Cool, unsettled, breezy.

Forecasts for North America

TODAY ... Showers, breezy in Great Lakes region, quite cool with winds veering SW to NW-N 20-30 mph, highs only 12-15 C. Some sunshine further east along the Atlantic coast fading to cloud later, 18-20 C. The chilly air mass will be centered in Saskatchewan and Manitoba where highs only about 12 to 15 C, and will extend well south of the border towards the south-central plains but the Gulf coast will remain warm to hot; the front is somewhat inactive across those regions although a sharp windshift can be expected. Sunny and very warm to hot further west, marine cloud beginning to encroach in a few coastal sections.

My local weather on Wednesday was once again sunny, hazy and very warm with highs about 23-25 C in a slight sea breeze.

M.T. Cranium · 20-09-2012 6:14pm

UPDATE _ Thursday 20 September 2012 _ 6 p.m.
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Rainfall amounts overnight are likely to reach 10-20 mm in a zone extending from north Connacht to central Leinster. On either side of that zone, much smaller amounts are likely trending to zero at each extreme (southwest, northeast) with a fairly sharp decline in amounts away from a relatively narrow band that will extend later from about Athlone to Wicklow as it pivots around a developing wave in north central Ireland and generally moves southeast.

As to the Monday potential storm, models are now in chaos and I am awaiting the new verdict of the European model. The GFS is holding to a fairly strong storm event as described earlier. But it now shows Nadine tagging along through Spain and France into southeast England as the Ireland low loses intensity mid-week. This looks suspiciously near-impossible to verify. The GME model could be said to be holding a weaker but similar solution for the weekend but their output ends at 72h ... The reasonably reliable GEM and UK models have lost much of their earlier intensity for the Monday event and continue to track Nadine away from Europe after the weekend. So this leaves us waiting with heightened anticipation for the "big gun" European model and its latest guidance. Will report back on that around 7:30 p.m.

M.T. Cranium · 20-09-2012 7:49pm

UPDATE (2) _ Thursday, 20 September, 2012 _ 7:45 p.m.
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The ECM more or less "holds serve" on the Monday storm although the loop is now slowed down to the extent that the strongest winds would likely develop late overnight into Tuesday morning. Some very strong NE winds would affect northern England and Scotland on Monday and could reach parts of Ulster briefly but on the depicted track, most of Ireland would see gradually increasing S-SW winds that look strongest around Cork and Kerry while Connacht and perhaps Donegal would see a period of strong NW winds as the low moves west towards them. This is going to be a challenging event to forecast and to explain as a lot of the development will occur somewhat opposite to normal Atlantic low patterns. That is, of course, if the ECM supported by the GFS are correct. The ECM also brings "Nadine" into southern Spain around Tuesday and then northeast across France (as a presumably 30-40 knot tropical depression becoming extratropical) into southern England. This might provide another looping storm involving our forecast by end of the week, but I continue to have doubts about this European destination given the known tendency of the LGEM model to handle such tracks better (and it takes the storm back towards Bermuda).

This is going to be a very interesting set of forecasts, will be checking other threads for your ideas (post them there as this thread gets a lot of mobile access, thanks.)

M.T. Cranium · 21-09-2012 6:35am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Friday, 21 September, 2012
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The GFS and GEM models continue to show a looping storm that reaches the west coast of Ireland and allows wind directions to swirl around in various directions on Monday and Tuesday. The ECM has slightly shifted away from that track to a loop around Britain which keeps Ireland in a strong northeast flow. Other European-based models (UK and GME) show a weaker variation of that scenario. Our forecast will follow the ECM partly because of its reliability and partly because it is near the average in any case. The ECM is slower moving Nadine away from the Azores and hints at a southwest track still, but then loops it around towards Portugal before stalling the remnant near northwest Spain ... none of the model solutions for Nadine have much reliability yet, there is still a chance it might move away from Europe altogether or die out somewhere west of Morocco. )

ADVANCE ALERT continued for possible heavy rain and strong winds from mid-day Sunday into Monday and Tuesday covering large parts of the country. Details in forecasts, but in general the looping weather system could bring total rainfalls of 30-50 mm and some local wind gusts of 45-55 mph.

Forecasts for Ireland

TODAY ... Rain or drizzle becoming rapidly confined to southeast followed by partial clearing, rain ending mid-day in the southeast with a further 5-10 mms there, some sunny breaks mid-day and afternoon with highs only 12-15 C in all areas. Winds rather light but a trend towards northerly breezes then calm at night.

TONIGHT ... Clear intervals, mist or ground fog developing, frost possible well inland in valleys. Lows generally 2-6 C but locally -1 C in calm conditions.

SATURDAY ... Partly cloudy with some good sunny intervals possible before becoming more overcast from higher cloud spreading in from south, showers possible near southwest coast by evening ... highs about 15-17 C. Winds generally light and variable in the morning becoming more east to northeast at about 10-15 mph later.

SUNDAY ... The morning may be dry for most of the north and west, with drizzle moving into the southeast. Cold to start with frosts in Ulster and Connacht inland, lows -1 to +4 C, but 5-8 C southeast. Increasing cloud with showers or periods of rain by evening, 10-20 mms possible by midnight, and highs 13-16 C. Winds generally light at first then increasing to E-NE 20-40 mph.

MONDAY ... Periods of rain and moderate or even strong winds developing as low pressure loops around from Britain and across western counties by Monday night. Further rainfalls 20-40 mms possible, lows near 8 C and highs 12-15 C, with moderate to strong winds developing from the northeast at 30-50 mph with some potential for higher gusts. There remains some chance of a more cyclonic wind pattern especially in the south. Some parts of east Ulster and north Leinster could have intervals of thundery rain and torrential downpours as the low deepens over northern England.

MONDAY NIGHT ... Windy and wet, rainfall totals may reach 50 mms in places, and winds from the northeast at 30-50 mph. Lows near 7 C.

TUESDAY ... Variable cloud although mostly overcast, showers or periods of rain, the strong SW winds of Monday night easing during the day and then replaced later by NE to N winds of about 20-30 mph, chilly with lows near 7 C and highs 10-13 C. Further rainfalls of 10-25 mms.

WEDNESDAY ... Showery and cool, northerly winds 15-30 mph, lows near 6 C and highs near 13 C.

OUTLOOK ... Slow improvements but rather unsettled and cool for several more days, even a slight chance of a second significant low that would represent whatever is left of "Nadine" (although still the chance that Nadine will never reach Europe at all, but if it does a more plausible track is into central Europe) ... eventually the possibility of frosts returning as cloud becomes less continual.

Forecasts for Britain

TODAY ... Periods of rain moving further south, partial clearing across north-central regions, cool. Rainfalls in south could reach 20-30 mms in a few locations before the system dies out over the Channel by evening. Highs 12-15 C north to 15-17 C south. Moderate northerly winds in some exposed locations but generally rather slack wind gradients with local valley effects.

TONIGHT ... Clear intervals, chilly, some frosts developing, lows -2 to +4 C in most regions to 7 C around London.

SATURDAY ... Sunny intervals, morning frosts possible, fog patches. Highs about 15-18 C south. Further north, highs 13-16 C. Rain arriving by late afternoon or evening in the southwest where the day may be mostly cloudy from remnants of the Friday frontal system.

SUNDAY-MONDAY ... Stormy at times with heavy rainfalls, strong east winds becoming more northeast then swirling around to west or southwest. Temperatures steady 12-14 C and rainfalls 30-40 mms in many places. Details depend on track but strongest winds likely to hit North Sea coasts and eastern Scotland during deepening phase Monday, and possibly Wales on Tuesday from southwest.

OUTLOOK ... Continuing rather cool, unsettled, breezy. There is a possibility of a second wind and rain storm in the south from remnants of "Nadine" around Thursday or Friday. If not this period will still be unsettled and breezy.

Forecasts for North America

Continued rather cool and unsettled in the Great Lakes and chilly across the Midwest and northern plains, central and eastern prairies as modified arctic air continues to stream south. A reinforcing shot of cold air on the weekend will drop maximum temperatures to only 7-12 C in many of these regions. Not quite that chilly further south although below average near 21 C Mid-Atlantic to 24 C southeast states. The trend going further west is hotter until almost the Pacific coast, but the warm spell is being eroded by slow encroachment of marine layers of cooler, moist air with fog patches drifting some distance inland. My local weather featured some of these fog patches mostly off to the south and west allowing hazy sunshine to continue but with thin layers of elevated stratus dimming the sun. This made things a bit cooler than recently with highs near 22 C.

Further discussion of the Sunday-Monday-Tuesday storm situation can be found in a new dedicated thread on the weather forum.

kerry4sam · 21-09-2012 4:48pm

@ M.T. Cranium: Have you ever thought of creating an app for mobile-use whereby people can choose the area they would like the forecast for and save their settings accordingly ... M.T. Cranium gone mobile?

Just curious.

M.T. Cranium · 21-09-2012 5:55pm

You may or may not be surprised to learn that I am almost entirely clueless (wait this goes on) about mobile phones, apps, twitter and everything that happened on the internet since about 2005. Hence I would have to toss questions like that over to other stake-holders who do know about such matters. This has actually been slowly emerging from back of mind for me since I expanded the forecasts to include Britain, and learned recently that what used to be the IWO forum is now "meteotimes" plus the existence of a facebook group that receives this forecast. So I will open up a thread to ask about potential restructuring and improvements to this free service, noting that I genuinely don't want to inconvenience my loyal readers with overly long or complicated messages.

Look for that thread to open later today.

I will have some updated thoughts about the Monday-Tuesday (and now apparently -Wednesday) event later, once the big guy shows up (ECM).

Once again, direct your comments about the service to this new thread.

M.T. Cranium · 21-09-2012 8:00pm

UPDATE _ Friday, 21 September, 2012 _ 8 p.m. IST
__________________________________________________

The autumn equinox occurs on Saturday 22nd at 1450h UT or 1550h IST and if you're wondering why it's not today, the autumnal equinox is almost always on the 22nd or 23rd, the reason is related to the somewhat slower movement of the earth around the Sun in summer. The March equinox would appear even earlier except that we have a short month in February for the opposite reason, the earth travels fastest in n.h. winter.

Mother nature apparently jumped the gun on that seasonal change in some parts of the hemisphere (not here) ... meanwhile, the update on the Monday to Wednesday storm potential is that all models are continuing with their earlier themes and a somewhat slower evolution has crept into the timing, so would expect the heaviest rain Monday night and Tuesday, with mainly northeast winds for Ireland although on some models there would be a period of backing (N to NW) gales in the southwest quadrant of Ireland while the low was both deepening and moving west towards Leinster (or Ulster, the consensus has shifted south on this). Also, Nadine is now abandoned to the Atlantic Ocean and her European visit is off again. That was being advertised for about Friday but by then Nadine could actually be closer to Bermuda than Iberia. It may eventually slog north and come at Ireland as a weak remnant low from the more normal west to east direction. The ECM is still trying to bring it east but I suspect the consensus trend will win out. However, Nadine could be wandering around somewhere not far from the Azores for quite some time.

M.T. Cranium · 22-09-2012 7:28am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Saturday, 22 September, 2012
___________________________________

ADVANCE ALERT continued for possible heavy rain and strong winds from mid-day Sunday into Monday and Tuesday covering large parts of the country. Details in forecasts, but in general the looping weather system could bring total rainfalls of 30-50 mm and some local wind gusts of 45-55 mph. This storm will likely reach its peak intensity Monday night into Tuesday morning.

Brief situational update -- Most models are continuing with earlier themes but there is now growing consensus on a looping storm track that will extend from northern England Monday night towards Dublin or possibly Ulster and then towards the south on Tuesday -- this may mean that strongest winds will be pushed gradually from east to west as the low pressure approaches. Winds would tend to back from northeast to northwest in some western districts, while further south moderate winds would back from northwest to southwest, and then all would come around to the northeast later Tuesday (in some cases after falling off calm). A pattern of strong winds to calm to moderate winds could be expected in eastern and central counties as the low centre approaches, passes through and moves away. There is still some spread in possible outcomes, and the location of heaviest rain will probably run just north of the low's eventual track southwestward. At the moment, that would suggest east to central Ulster, inland Leinster to east Connacht, and central Munster.

Forecasts for Ireland

TODAY ... Partly cloudy although overcast near south and west coast this morning, with some good sunny intervals possible especially inland towards Ulster, before becoming more overcast from higher cloud spreading in from south, showers possible at times near outer west coast, little if any accumulation for most places ... highs about 15-17 C but could be held down to 12-14 C under low cloud. Winds generally light and variable in the morning becoming more east to northeast at about 10-15 mph later.

TONIGHT ... Clear intervals central and inland east, north, low cloud and drizzle elsewhere, some local frost possible but a rising trend after about 02h as calm winds yield to moderate easterlies. Lows 1-4 C for most but 5-8 C in parts of south and near some other coasts.

SUNDAY ... The morning may be dry for most of the north and inland central to west, with drizzle moving into the southeast and light rain in west coast regions by afternoon. Cold to start with frosts in Ulster and Connacht inland. Under variable cloud, highs about 13-15 C but some places could stay cooler with low cloud cover. Increasing cloud with showers or periods of rain possible by evening mainly in Wexford and nearby southeast, 10-20 mms possible by midnight. Winds generally light at first then increasing to E-NE 20-40 mph.

SUNDAY NIGHT into MONDAY ... Periods of rain and moderate or even strong winds developing as low pressure loops around from Britain and across western counties by Monday night. Further rainfalls 20-40 mms possible, lows near 8 C and highs 12-15 C, with moderate to strong winds developing from the northeast at 30-50 mph with some potential for higher gusts especially in Ulster by late afternoon. Strong northwest winds will develop in Donegal and Mayo late in the day (35-55 mph) and similar but backing to west in Clare and Kerry. Some parts of east Ulster and north Leinster could have intervals of thundery rain and torrential downpours as the low deepens over northern England.

MONDAY NIGHT ... Windy and wet, rainfall totals may increase by another 10-20 mms in places, and winds from the northeast at 30-50 mph, easing near the storm track when the low centre approaches east Leinster. Strong winds continuing across the west (NNW 30-50 mph). Lows near 7 C.

TUESDAY ... Variable cloud although mostly overcast, showers or periods of rain, continued heavy in Leinster during the day, storm totals of 50 mms or more possible ... the strong winds of Monday night easing during the day and then replaced later by NE to N winds of about 20-30 mph, chilly with highs 10-13 C. Further rainfalls of 10-25 mms. Local flooding may develop after prolonged heavy rains.

WEDNESDAY ... Showery and cool, northerly winds 15-30 mph, lows near 6 C and highs near 13 C.

OUTLOOK ... Slow improvements to partly cloudy and cool for several more days, even a slight chance of a second significant low that would represent whatever is left of "Nadine" which could arrive from south or west depending on where it goes after tomorrow's approach to Madeira. Some models have it tracking west then north into the central Atlantic and remnants would reach Ireland around Sunday 30th to Tuesday 2nd October; other model forecasts have the remnant low drifting east then north through Biscay and possibly as far as Ireland although in some cases just into western France while it dies out, in the same time frame (30 Sep to 2 Oct).

Winter forecast posted in winter 2012-13 thread ... preliminary ideas ... generally a mild start with some colder intervals in December and January, trending to much colder in February when snow could become more of an issue. I will post a final seasonal forecast mid-October.

Forecasts for Britain

TODAY ... Sunny intervals, fog patches dissipating. Highs about 15-18 C south. Further north, highs 13-16 C. Rain arriving by late afternoon or evening in the southwest where the day may be mostly cloudy from remnants of the Friday frontal system. Some showers in the northwest by late afternoon.

TONIGHT ... Increasing cloud south, some light rain near Channel, clear intervals and frosty further north, lows there only -2 to +4 C.

SUNDAY-MONDAY ... Stormy at times with heavy rainfalls, strong east winds becoming more northeast then swirling around to west or southwest. Temperatures steady 12-14 C and rainfalls 30-40 mms in many places. Details depend on track but strongest winds likely to hit North Sea coasts and eastern Scotland during deepening phase Monday, and possibly Wales on Tuesday from southwest.

OUTLOOK ... Continuing rather cool, unsettled, breezy. Highs 14-17 C.

Forecasts for North America

Similar to yesterday as systems have almost stalled out. Cool and showery east, dry and cool east-central, warm/dry further west, some west coast low cloud and fog. My local weather on Friday was cloudy and much cooler as the marine layer moved in (about 50 kms, further inland it was very warm again). Our high was only 16 C.

M.T. Cranium · 23-09-2012 8:00am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Sunday, 23 September, 2012
___________________________________

ALERT continued for possible heavy rain and strong winds from late Sunday into Monday and Tuesday covering large parts of the country. Details in forecasts, but in general the looping weather system could bring total rainfalls of 30-50 mm and some local wind gusts of 45-55 mph. This storm will likely reach its peak intensity Monday night into Tuesday morning.

Forecasts for Ireland

TODAY ... The morning may be dry for most of the north and inland central to west, with drizzle moving into the southeast and light rain in west coast regions by afternoon. Cold to start with frosts in Ulster and Connacht inland. Under variable cloud, highs about 13-15 C but some places could stay cooler with low cloud cover. Increasing cloud with showers or periods of rain possible by afternoon into evening mainly in Wexford and nearby parts of south Leinster, 10-20 mms possible by midnight. Winds generally light at first then increasing to E-NE 20-40 mph.

TONIGHT ... Rain will edge further north but will be largely confined to coastal Wexford, Wicklow with 10-15 mms possible there. Light rain or drizzle could break out elsewhere with slight amounts. Cold and windy, lows near 7 C and winds NE 20-35 mph.

MONDAY ... Periods of rain and moderate or even strong winds developing as low pressure loops around from Britain and across western counties by Monday night. Rainfalls 20-40 mms possible but amounts before evening generally 5-15 mms, highs 12-15 C, with moderate to strong winds developing from the northeast at 30-50 mph with some potential for higher gusts especially in Ulster by late afternoon. Strong northwest winds will develop in Donegal and Mayo late in the day (35-55 mph) and similar but backing to west in Clare and Kerry. Some parts of east Ulster and north Leinster could have intervals of thundery rain and torrential downpours as the low deepens over northern England during the evening.

MONDAY NIGHT ... Windy and wet with some thunder in north, rainfall totals may increase by another 10-20 mms in places, and winds from the northeast at 30-50 mph, easing near the storm track when the low centre approaches east Leinster. Strong winds continuing across the west (NNW 30-50 mph) and occasional westerly gusts to about 40 mph south coast. Lows near 7 C.

TUESDAY ... Variable cloud south although mostly overcast, cloudy elsewhere, further showers or periods of rain, continued heavy in Leinster during the day, storm totals of 50 mms or more possible (additional rainfalls then of about 15-25 mms) ... the strong winds of Monday night easing during the day (Leinster could remain in light winds for much of the day), some regions of south in cyclonic swirling wind pattern, then changing later by NE to N winds of about 20-30 mph, chilly with highs 10-13 C. Local flooding may develop after prolonged heavy rains.

WEDNESDAY ... Showery and cool, northerly winds 15-30 mph, lows near 6 C and highs near 13 C.

OUTLOOK ... Slow improvements to partly cloudy and cool for several more days, even a slight chance of a second significant low that would represent whatever is left of "Nadine" -- models are beginning to converge on a weaker solution that either strands the remnants south of the Azores high, or brings a remnant north towards Iceland and northwest Scotland (by 2-3 Oct).

Winter forecast posted in winter 2012-13 thread ... preliminary ideas ... generally a mild start with some colder intervals in December and January, trending to much colder in February when snow could become more of an issue. I will post a final seasonal forecast mid-October.

Forecasts for Britain

TODAY, TONIGHT into MONDAY ... A dry start for most, rain edging north into Cornwall and Devon, then moving faster northward by mid-day, reaching Wales and Midlands by afternoon or early evening. Stormy at times with heavy rainfalls, some thunder embedded, strong east winds becoming more northeast then swirling around to west or southwest. Temperatures steady 12-14 C and rainfalls 30-40 mms in many places. Details depend on track but strongest winds (E-NE 40 to 60 mph) likely to hit North Sea coasts and eastern Scotland during deepening phase Monday, and possibly coastal Wales and southwest on Tuesday from a south to southwest direction.

OUTLOOK ... Continuing rather cool, unsettled, breezy. Highs 14-17 C.

Forecasts for North America

A pleasant fall day across most of the U.S. with scattered showers and cool northwest winds in parts of the Great Lakes region. Temperatures generally a bit below normal in the east, and considerably above normal south-central and western regions. Coastal low cloud breaking up in parts of B.C. and Washington to return those regions to warm sunshine.

My local weather on Saturday was overcast with highs near 19 C. Hazy but clear intervals overnight and hazy sunshine, 22 C expected here on Sunday.

M.T. Cranium · 23-09-2012 8:03pm

UPDATE _ Sunday, 23 Sept 2012 _ 8:00 p.m.
___________________________________________

There is just enough difference in the guidance for the approaching storm that we are forced to give a range of possible outcomes.

If the GFS model is correct, the storm centre will never reach Ireland and this will allow very strong winds and heavy rainfalls to overspread almost all of eastern Ireland Monday night into Tuesday morning. In this scenario, Dublin, Meath and Kildare could all see 40-60 mms of rain and winds from the northeast approaching 65 mph in gusts (110 km/hr), sustained around 40 mph or 70 km/hr. This scenario would also give heavy rainfalls in east Ulster and other parts of Leinster, trending down to about 15-30 mms west and south. Winds across these other regions would tend to peak about 30 mph gusting to 50 mph and almost the entire storm would be a northeasterly wind event.

If other models are correct, and there is little variation among them, the storm will take a wider loop that brings the centre across Ulster into west-central Ireland and out to the south by late Tuesday. This track would give a much less significant storm to Dublin and some nearby counties, and would take the heavier rain across Ulster into the north central counties, although this heavier rain would also tend to be somewhat less in total, 30-50 mms in Ulster and 20-40 mms inland central Ireland, trending down to 10-20 mms around all coasts except the north. Wind speeds could be 30-50 mph across Ulster and parts of Connacht trending to 20-40 mph in Munster and Leinster, except for some higher gusts in north Leinster Monday night during the phase where very strong winds are hitting east Ulster.

My gut feeling is that the outcome will be a blend of these, not quite the GFS track but possibly something like a track running from Louth to Kildare to Waterford. This would place Dublin under the calm eye of the storm at some point around Tuesday morning. It would also imply heaviest rainfalls along and to the north of that track, so Westmeath, Meath, Cavan, Monaghan, Armagh and Down could see the heaviest rainfalls of 35-55 mms. My blend track would be much less windy than the GFS for Dublin and large parts of Leinster although very windy for Belfast and most of Ulster.

However, this is all speculation within the uncertainties at this time range, forecast followers will have to accept that we are into a "nowcasting" situation to some extent and that all regions especially Leinster and Ulster should be on alert for the potential of very heavy rainfalls and very strong winds depending on the exact outcome. Next update likely around midnight.

M.T. Cranium · 24-09-2012 7:14am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Monday, 24 September, 2012
___________________________________

ALERT for heavy rainfalls and strong winds later today, overnight and Tuesday, storm totals of 40-80 mm possible, in parts of Leinster and Ulster, 20-40 mm west Ulster, Connacht, Munster. Winds northeast 30-50 mph in exposed locations (by later afternoon and overnight) with risk of isolated storm force winds 45-65 mph coming inland around Balbriggan across parts of Meath, north Dublin. Also very windy at times in Donegal. Non-severe wind gusts expected in most of Connacht and Munster.

Situation update: 985 mb low currently east of Bristol heading north with torrential rain over most of Wales. Increasingly, the rain with this system is shifting to the west side of the circulation. Model consensus has shifted to a tighter "loop" track towards the Isle of Man then back to southwest, that keeps the deepening low over the Irish Sea and possibly near the Wexford coast by late Tuesday before it weakens and moves away on Wednesday. The ECM and GEM have the low over central Britain then move it southwest through Wales towards Wexford. Development continues as upper level low pressure moves rapidly southeast to interact with this surface low. A separate trough near the west coast will be pulled into the larger circulation soon. Heavy rain will spread west and a "rainfall max" or convergence zone could develop from about Belfast south towards central Meath and north Kildare. This zone could also be closer to the coast, depending on which model handles this best. West of that feature, banded moderate rainfall is likely in a northerly flow. Although it is still a "nowcast" situation to some extent, it does seem likely to be a relatively severe rain and wind event for parts of Leinster.

Forecasts for Ireland

TODAY (MONDAY) ... Periods of rain and moderate or even strong winds developing as low pressure drifts northwest into the Irish Sea. Rainfalls will be generally light until mid-day then may become rather heavy in the east, with 20-40 mms possible by midnight but amounts before evening generally 5-15 mms. Cold and windy with highs 12-15 C, with moderate to strong winds developing from the northeast at 30-50 mph with some potential for higher gusts especially in Ulster and north Leinster by late afternoon. Strong northerly winds will develop in Donegal and Mayo late in the day (35-55 mph) while in Clare and Kerry moderate NW winds of 20-40 mph can be expected, Galway Bay around 30-50 mph NNW. Some parts of east Ulster and north Leinster could have intervals of thundery rain and torrential downpours as the low deepens over northern England during the evening.

TONIGHT ... Windy and wet with some thunder in north, rainfall totals may increase by another 15-30 mms in places, and winds from the northeast at 30-50 mph, possible increasing at times to 45-65 mph in a zone from around Balbriggan southwest into north Kildare. Strong winds continuing across the west (NNW 30-50 mph) and occasional westerly gusts to about 40 mph south coast. Lows near 7 C.

TUESDAY ... Variable cloud south although mostly overcast, cloudy elsewhere, further showers or periods of rain, continued heavy in Leinster during the day, storm totals of 40-80 mms possible (additional rainfalls on Tuesday then of about 15-25 mms) ... risk of heaviest rain in a convergence zone situation just west of Dublin. Rather cold with highs 10-13 C. Winds may ease slightly near the southeast coast but many places could have strong winds at times all day from a N to NE direction, 35-55 mph in exposed areas and 20-40 mph generally. Local flooding may develop after prolonged heavy rains. This seems to be most likely Tuesday morning.

Flood risk seems greatest in Down, Armagh, Louth, Meath, Dublin, Kildare, Westmeath and nearby parts of Monaghan, Cavan, Longford.

WEDNESDAY ... Showery and cool with some hail or thunder in a few locations, northerly winds 15-30 mph, lows near 6 C and highs near 13 C.

OUTLOOK ... Slow improvements to partly cloudy and cool for several more days, even a slight chance of a second significant low that would represent whatever is left of "Nadine" -- models are beginning to converge on a weaker solution that either strands the remnants south of the Azores high, or brings a remnant north towards Iceland and northwest Scotland (by 2-3 Oct).

Forecasts for Britain

TODAY ... Heavy rain across Wales and nearby parts of western England, where winds rather light due to proximity of low centre, otherwise showers with some brighter intervals in gusty southeast winds 30-50 mph. Also some heavy bands of rain across southern Scotland where winds likely to be strong easterly at times 40-60 mph. The southwest counties of England will see thundery showers at times and strong SW winds 35-55 mph. Temperatures steady 11-13 C in the heavier rain, otherwise 13-16 C, and rainfalls 30-60 mms in many parts of Wales.

TONIGHT ... Some continuing heavy rains in Wales, showers redeveloping further east and gusty SW winds for most, light winds in Wales, strong SE winds in Scotland. Lows 7-9 C. Further rainfalls of 20-40 mms in Wales could produce severe local flooding in Severn drainage.

OUTLOOK ... Continuing rather cool, unsettled, breezy. Highs 14-17 C.

Forecasts for North America

Little change from yesterday, warm and dry across most of the U.S. except near the Great Lakes with a few showers in a blustery W-NW wind, and also some thunderstorms over Utah and Colorado moving into the central plains states overnight. My local weather on Sunday was partly cloudy and hazy with highs of about 20 C.

Check the ongoing storm thread for updates on forecast ideas and model depictions of the developing storm. I will try to update from time to time

M.T. Cranium · 24-09-2012 6:05pm

UPDATE _ Monday, 24 September, 2012 _ 6 p.m. IST
__________________________________________________

The ALERT is maintained for heavy rainfalls in Leinster and east Ulster with amounts of 30-50 mms already reported in some places, and more than that likely to fall in the next 24 hours (40-80 mms possible in some locations in Dublin and Meath). Severe flood potential exists with these ongoing heavy rainfalls, likely to peak Tuesday morning to mid-day although the rain will continue beyond that well into Tuesday night. There could be some thunder with the heaviest rain late tonight.

I have posted a longer synopsis on the storm's track in the storm thread, basically, it appears likely that the low centre now in north-central England will drift west tonight past the Isle of Man towards Dublin, turning more to the south as it passes Anglesey. This track, combined with further development (central pressure now at 983 mbs likely to fall to 973 mbs) will produce much stronger N to NE winds across the Leinster coast and in east and north Ulster. Some local gusts to 60 mph could develop late tonight, especially from Balbriggan north to about Antrim. Local topography could channel these winds in areas around Belfast. The strongest winds might therefore be expected to come inland west of Dublin while the capital may see less blustery winds at least until mid-morning Tuesday when the low will have moved a bit further south to allow the strong winds to move down the coast. Eventually the heavier rains and stronger winds will arrive in the southeast later Tuesday. There will be much less rain and more moderate wind speeds in the western half of the country but as the rainfall becomes banded there will be local variations between 10 and 30 mms in total. Some parts of the southwest could remain almost dry.

Next update likely around 10:30 p.m. ... this will be a "high impact" event for parts of Leinster and east Ulster and the worst of the storm is likely to be late tonight and Tuesday morning. This is also about when I would expect any severe flooding to reach its crest. Let's hope the rivers and streams can handle the expected downpours, but I believe there is a risk of severe river and urban flooding in this scenario.

M.T. Cranium · 24-09-2012 11:06pm

UPDATE _ Monday 24 Sep 2012, 11 p.m.
_____________________________________

Conditions are generally wet but not really that stormy yet ... but the main impact of this system will probably come between 0400h and 1200h as the low deepens and moves much closer to Ireland. Thus, no change in the general outlook, still expecting heavier rain to develop late tonight with the risk of strong winds especially for Ulster and north Leinster. No sharp cutoff seems likely for rainfall across the west, in fact some parts of Connacht could see equal amounts to inland Leinster as the storm creates spiral bands of moisture. Some very interesting effects are likely in coastal Leinster when the deep low arrives offshore, so we'll reconvene at 0630h or whenever you start your day. Any significant updates before then will go into the storm thread.

M.T. Cranium · 25-09-2012 7:37am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Tuesday, 25 September, 2012
___________________________________

ALERT continued for heavy rainfalls and strong winds today and Wednesday, storm totals of 40-80 mm possible, or close to 100 mms (due more to long duration than any increase in hourly rate) in parts of Leinster and Ulster, still expecting about 20-40 mm west Ulster, Connacht, Munster. Winds northeast 30-50 mph in exposed locations today and tomorrow with risk of isolated storm force winds 45-65 mph coming inland around Balbriggan across parts of Meath, north Dublin. Strongest winds will be moving further south on Wednesday. Also very windy at times in Donegal. Non-severe wind gusts expected in most of Connacht and Munster.

Situation update: 975 mb low near Newcastle, England with western centre gradually developing over northeast Irish Sea replacing this older centre (about 979 mbs at present). This low will drift southwest towards Anglesey then across western Wales and southern England in the next two days, slowly filling, but from rather conflicting guidance, the possibility exists that the low will remain rather deep all day today, tonight and only start to fill tomorrow. Minimum pressures could reach 973 mbs late today. These developments will tend to ramp up wind speeds gradually and although rain may break up to bands of showers, some of those could then become heavier than the light rain overnight. Mainly because of the longer duration of the event, I am maintaining flood risk and high rainfall totals as per earlier forecasts. Wind speeds may not make it to storm force but the potential will be there and it's still somewhat of a nowcast situation for the next 36 hours.

Forecasts for Ireland

TODAY ... Mostly overcast, further showers or periods of rain, continued heavy in Leinster during the day, 15-25 mms liikely, bringing storm totals to 40-100 mms ... risk of heaviest rain in Dublin and Meath, spreading south into Wicklow later. Other areas of heavy rain likely at times in east Ulster, isolated parts of northwest counties. Rather cold with highs 10-13 C. Northeast winds increasing to reach 35-55 mph in exposed areas and 20-40 mph generally. Risk of stronger gusts will be closely watched (see updates). Local flooding may develop after prolonged heavy rains. This risk will be spreading south tonight, and there could be local tidal high water on east coast.

TONIGHT ... Further rains of 10-20 mms possible, Wicklow and Wexford now getting heavier rain but it could continue across most of Leinster and east Ulster. Showers further west in gusty NE to N winds 25-45 mph (backing at times to NW in Kerry, Cork).

WEDNESDAY ... Showery and cool with some hail or thunder in a few locations, northerly winds 15-30 mph, lows near 6 C and highs near 13 C. Rain could continue in southeast for part of the morning before breaking to showers.

OUTLOOK ... Partly cloudy, isolated showers Thursday-Saturday with more seasonable highs in the 14 to 17 C range, cooler nights (3-7 C) ... weekend showery to start, improving later.

Forecasts for Britain

TODAY ... Heavy rain across north Wales and nearby parts of northern England, strong east winds mainly confined to Scotland but spreading back to northern England later, moderate to strong SW winds across southern England, scattered hail or thunder showers. Highs for most 13 to 16 C.

TONIGHT ... Rain becoming heavier again in Wales, spreading to southwest and south central England, west Midlands. Rain becoming showery or drizzly further north. Lows 7-9 C. Continuing windy in south and parts of north, Scotland, lighter winds returning to Wales.

OUTLOOK ... Continuing rather cool, unsettled, breezy. Highs 14-17 C. Winds not as strong in the south by later Wednesday.

Forecasts for North America

Showery in parts of the Midwest and Great Lakes, dry and warm southeast, east coast, inland to about Pittsburgh to Louisville, highs generally 24-27 C east but 16-20 C further north. West still largely warm and dry. My local weather on Monday was cloudy with hazy sun at times, highs near 20 deg C.

Check the storm thread for updates ... the most active part of this storm appears to be slightly delayed but would expect it to be mid-day or afternoon from Dublin north, this evening further south and late overnight southeast.

M.T. Cranium · 26-09-2012 7:03am

Important: Please note legal disclaimer published once a month, can be seen at bottom of post 2565 dated 24 July 2012.

Wednesday, 26 September, 2012
___________________________________

Update ... The low began to travel much faster around midnight and is already well south of Dublin over Cardigan Bay (Wales) heading towards Monday's position over southern England. It is also rapidly losing intensity although a few more hours of gusty winds can be expected. By late tonight, the blocking pattern will break down and more normal westerly flow will resume. Further rain and wind are gradually becoming sub-alert criteria but the accumulated rainfalls could still produce ongoing flooding in a few locations especially in North Dublin and Meath.

Forecasts for Ireland

TODAY ... Blustery with further showers, heavier in the southeast this morning, amounts 10-15 mms in places, NNE winds 30-50 mph. Further west, partly cloudy to overcast with drizzle or light rain at times in northerly winds 20-35 mph. Continuing cool with highs 11-14 C.

TONIGHT ... Clear intervals followed by increasing cloud, chilly, lows about 4 to 7 C, temperatures rising somewhat towards morning. Moderate NW winds mostly in exposed coastal locations.

THURSDAY ... Cloudy north, partly cloudy south, breezy to windy at times from the west. Somewhat milder especially for the south, highs 11-15 C.

FRIDAY ... Early morning showers or periods of rain, gusty southwest to west winds 25-45 mph, then variable cloud, a few more showers mainly in Connacht, morning lows near 9 C and afternoon highs about 15 C.

SATURDAY ... Partly cloudy, mild for most, cloudy with outbreaks of light rain in the north, lows near 6 C and highs near 17 C.

SUNDAY ... Variable cloud, showers, mild, southwest winds becoming blustery again later, lows near 8 C and highs 14-16 C.

FURTHER OUTLOOK ... Unsettled for the first part of the week (1-5 Oct) then a more settled and calm weather pattern with fog at night, hazy sunshine in the daytime. Rather mild days but chilly nights.

Forecasts for Britain

TODAY ... Outbreaks of rain across Wales and southern England, drizzle at times in the north, some sunny breaks and showers for eastern England with south to southwest winds 20-40 mph (35-55 mph exposed coasts). About 20 to 30 mms further rain in some places. Highs generally 12-15 C.

TONIGHT ... Light rain southern England, drizzle elsewhere, fog developing. Lows about 6 C.

OUTLOOK ... Showery at times although longer dry intervals in south, near normal temperatures from Thursday to Sunday. Windy by Friday in Scotland.

Forecasts for North America

Outbreaks of severe storms in a few parts of the Midwest and more widespread showers, gusty southwest winds. Staying dry and warm in some parts of the east-central and southeast U.S. The long warm, dry spell over the west continues with just isolated showers, but fronts are now beginning to break down the dry conditions in central B.C.

My local weather on Monday was hazy with sunshine during the afternoon, highs of about 20 C.

Your daily forecasts from Boards.ie weather forum (NO CHAT)

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