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

Tuesday, 30 November, 2010
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A wedge of milder air has been created mostly from the stronger winds now blowing across the Irish Sea -- this has caused the snow to change to sleet or rain near the Leinster coast but heavy snow has been reported at higher elevations and further inland, almost as far as the west coast in central Ireland. It appears that even colder air is mixing through from the northeast and the forecast will reflect the potential for renewed heavy snow in most areas.

TODAY ... morning sleet or rain near the east coast, outbreaks of heavy snow continuing in central and inland eastern counties and as far west as Galway at times. Much of the south remaining cloudy with only flurries and a few sunny intervals while Ulster will probably see gradually colder conditions and outbreaks of snow. By mid-day and afternoon, expect renewed snow closer to the coast although some rain and sleet may continue in the mix at sea level. Overall, the heaviest snowfalls will likely be in higher parts of Dublin and Wicklow, inland Meath, Louth, east Ulster, Westmeath, Kildare, Laois, Offaly and nearby parts of other counties. Some places have had 10-15 cms and could see about that same amount more; other places will get snowfalls of 10-20 cms later on. There may also be some snow hitting south coast locations later from the east. Highs today will be registered in the morning hours, 2-4 C near the coast, 0-2 C inland. Winds will pick up to ENE 20-40 mph. Thunder and lightning are likely at times in all types of precipitation.

TONIGHT ... snow may continue in many areas as winds continue ENE 15-30 mph. Local snowfalls of 5-15 cms possible. A few areas may clear and drop quickly to about -8 C or lower, but in snow the temperatures will stay around -4 C.

WEDNESDAY ... partly cloudy, continuing streamers of snow in some eastern and southern counties as well as parts of Ulster. More sunshine likely in western counties. Winds E 15-25 mph adding a chill, highs -2 to +3 C.

THURSDAY ... more clear skies and daytime sunshine than previous days, but still some risk of coastal snow streamers. Morning lows could be especially low due to the clear skies, -7 to -12 C possible ... afternoon highs generally in the range of -1 to +3 C.

FRIDAY ... cloudy, outbreaks of sleet or snow in east and north, drizzle, mist and fog in south and west, as temperatures slowly moderate to about 4-6 C west/south, but remaining cold (1-3 C) elsewhere. Risk of some freezing rain. A slow thaw in west and south, but icy conditions likely elsewhere.

WEEKEND ... cold, outbreaks of sleet or snow, drizzle/fog/mist on some west and south coast headlands but most areas staying cold with highs only 2-5 C, overnight lows near -2 C. Winds becoming northerly again by Sunday.

OUTLOOK ... models want to try to end the cold spell temporarily from the southwest with low pressure attempting to push back the cold, but this looks suspiciously like a few earlier attempts that were downgraded closer to time -- and in any case, another outbreak of cold air seems very likely mid-week, from a northerly direction.

Briefly, weather here on Monday was cloudy with rain, 5 C.

Watch for updates, and I'm sure the forum will become very busy soon as people awake to their various weather situations ... but expect a colder turn and the balance swinging back towards widespread snow as the surface layers near the east coast cool down during the late morning and mid-day period.

I see what you mean, two things perhaps in your favour, one is that winds rarely stay exactly oriented the same way hour after hour so there is bound to be some oscillation of the streamers but also, as I posted in another thread, I see signs of colder air settling into the central and western counties that may drop temperatures there significantly by midnight, and this may have the effect of slowing down the surface E-NE winds and setting up that mesoscale wind boundary that we saw the other night, so don't be surprised if these streamers actually get heavier this evening and through the night, and develop a lot more thunder again. But as you can appreciate, trying to predict amounts of snow for each location out of streamers is difficult, I would just say there is potential for 5-20 cms more snow in many eastern districts tonight, but can't guarantee that for everyone. I gather the idea of moving the Isle of Man is being discussed.

Wednesday, 1 December, 2010
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TODAY ... Continuing very cold with local snowfalls of 5-15 cms mainly in the southeast from streamers coming inland off the Irish Sea ... light amounts of snow also possible more widely in north, central and southwest ... best of the sunshine in Connacht and the northern parts of Munster but the sun may break through at times in the east ... highs reaching about -1 C inland and about +2 C east coast, south coast. Winds generally ENE 15-25 mph near coasts and becoming E 10-15 mph inland when the morning chill lessens.

TONIGHT ... Possibly the coldest night of this arctic spell, due to widespread clear skies and light winds ... any drifting cloud would hold temperatures at around -4 C but clear skies would probably allow for lows of -8 to -12 C especially over recent snow cover. Freezing fog patches may become widespread too. Any flurries still active near the east coast will become confined to coastal Wicklow and south Dublin before dying out.

THURSDAY ... rather calm but cold, with sunny intervals, some cloudy areas and the chance of a few flurries mainly near coasts. Highs only -3 to +2 C.

THURSDAY NIGHT ... clear at first, clouding over from west after midnight, quite cold again in most areas, lows -5 to -9 C east, about -2 C west, south.

FRIDAY ... Snow possible inland northern counties, sleet or freezing rain in parts of Connacht, Midlands, inland Leinster, Ulster, and fog/mist/drizzle or light rain spreading slowly into coastal west and south ... the warming trend will be very gradual and may not extend to all of the northern half of the country ... highs will reach about +2 C north to +6 C west coast, +4 C east coast.

WEEKEND ... variable cloud, more flurries or hail showers likely, staying rather chilly with winds becoming northerly 10-20 mph ... lows will be around -2 C and highs around +4 C.

By Monday, a mixed precip event is possible as strong low pressure forms near Spain and moves into France and towards the Channel, placing Ireland in a northeast wind flow of about 15-30 mph and likely temperatures of about +2 to +5 C, ideal for mixing of precipitation types by elevation, so inland and especially higher areas could see more snow or sleet, while a chilly rain may fall near sea level. Don't be surprised if forecasts trend towards snow with this one too. This weather system will be followed by a slightly colder northerly flow again, and I am issuing my usual caution about any signs of milder weather on models beyond seven days, but even if the current GFS run was accurate, the warming would be rather subtle under high pressure, with continued very chilly nights likely.

Meanwhile, around Vancouver here, the weather on Tuesday was very wet, with as much as 50 mms of rain locally, and not too warm either at about 5-6 deg C. This rain has ended now but it remains overcast and rather foggy.

UPDATE _ Wednesday, 9:30 p.m.
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No big changes, forecast remains as per the earlier version through THURSDAY NIGHT, then latest guidance backs up the idea that any warming on Friday will be very much confined to the outer west and south coasts, where it could reach +5 C ... but for most places where people actually live, the cold air will be very tough to move with this weak, feeble warm front approaching, and the result is likely to be bands of freezing rain and snow to the north of a front that only makes limited progress inland during the day Friday. This may mean that areas now covered in snow will anchor the cold air in place and the freezing rain is more likely to be in areas that have little or no snow at present, while the areas now with snow cover could get some more on Friday.

The weekend continues to look quite cold with scattered wintry showers, and then the possible storm discussed for Monday-Tuesday is now (as suspected) being weakened on model runs to the extent that it's really just a continuation of a cold, northeast wind trend through that period and the effects of the storm will be held well off to the south and later southeast of Ireland as the low remains near northwest Spain throughout. What that means for the weather in Ireland is likely near-freezing temperatures continuing with outbreaks of light snow in the east.

Eventually higher pressure is likely to build across Ireland later in the week and may remain anchored nearby for several days. The upper portions of the atmosphere may warm with that, but the surface could remain bitterly cold due to the inversion created and the likely remnant snow cover. In other words, it may not be warming up very substantially, if at all, for a week or two and possibly more.

My research suggests that if the cold persists to about the 18th-19th before the full moon, then a winter storm will likely develop at that time (20th-21st), whereas if it does manage to get mild then this would become a rainfall event followed by colder weather. Thinking now that the odds would favour this being a winter storm event ... and possibly we are on our way to the coldest December in many years.

Don't shoot the messenger ... :cool::eek::cool:

Thursday, 2 December, 2010
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TODAY ... First, for the snow-bound southeast, continued bands of locally heavy snow are likely to continue for at least the morning hours with 5-15 cms further snow possible, but this heavier snow will become increasingly confined to the Wicklow coast by mid-day (some localized 20-30 cms falls possible there) ... snow bands in Meath, Dublin and Kildare as well as parts of Wexford, Carlow, Laois, Kilkenny and Waterford, should slowly taper off to flurries before some clearing develops ... the rest of the country should remain largely dry with sunshine for most (some low cloud, freezing fog patches) ... highs today will vary from about -2 C in parts of the inland west and north, to +3 C outer south coast, near the shore around Dublin and north coast.

Winds today will be generally light and variable except for the southeast where winds may continue NE 10-20 mph during the morning (hence the snow streamers).

TONIGHT ... clear and very cold (frigid in some cases) although a few coastal areas cloudy, lows inland falling to -12 C before warming somewhat after midnight, due to cloud spreading in ... lows of about -7 C closer to the east coast and south coast. Freezing fog may develop in many areas.

FRIDAY ... intervals of sleet, snow and (in the southwest inland mainly) freezing rain will develop during the morning and spread sporadically north and east during the day. Some snowfalls of 3-7 cms possible especially north central inland counties, higher parts of Mayo-Galway, and some eastern counties. Freezing rain risk likely to spread to some south central and inland southeast locations. West and south coast especially outer headlands may become milder for a while with low cloud, mist and drizzly rain as temperatures there rise to 5 C, but most other locations will stay near freezing and will be struggling to reach even +2 C.

SATURDAY ... some snow or freezing drizzle continuing, with a slight clearing trend from west to east later in the day ... cold, lows near -3 C and highs near +1 C.

SUNDAY ... variable cloud, scattered wintry showers of sleet, hail or snow with cold temperatures continuing, lows near -4 C and highs near +1 C.

MONDAY-TUESDAY ... cloudy with some brighter intervals in north, west ... some light snow or sleet near east coast spreading at times into south ... winds NE 10-20 mph ... temperatures close to freezing.

OUTLOOK ... higher pressure building up over Ireland will mean a period of cold nights and relatively cool days, with perhaps some chance of a slightly milder turn but also the risk of severe inversion cold at times ... the best bet is to expect a continuation of near-freezing weather so that the snow cover and ice that has already developed and that which is about to be added, will melt only gradually if at all. Temperatures can be expected to remain several degrees below December normals.

The hope is that there may be one or two milder days when the high moves a bit further west and allows some modified Atlantic air to reach Ireland from the northwest, but even that might be a faint warming trend.

Meanwhile, the Wednesday weather here was cloudy and mild at 10 deg C. A mild spell has just ended on the east coast, it was near 15 C earlier in Boston and NYC, but will be dropping to near -1 C soon, and some snow is possible on the east coast by the weekend. Where it's very mild (relatively) is in western Greenland, they have had several days of +7 C or milder there. :mad:

I think the forum regulars may be suffering snow fatigue, as some of the threads seem to be turning into advice for the lovelorn and shopping tips, but I'm sure we'll get back on track with some new form of snow to track on Friday. :cool: I will try to update as sleep allows.