Cold Spell Media Forecasts and Model Output (General Chat)

maquiladora

Based on what the 12Z GFS is showing, I think the St Stephens Day event will be mostly rain for the vast majority of people with the risk of snow mostly limited to those on high ground.

Dew point temps shown as being above 0, really needs to be 0 or below for snow instead or rain/sleet :



Upper air looks set to be above -5, precip usually falls as snow when upper temps are -5 or colder :



Thickness also doesn't look favourable for snow :



Of course that is just one run of one model and its still a few days away.

Not

ME calling the St Stephens day event as snow means it will certaintly be rain.

Duiske

irish1967 wrote: »

Thanks Cherryghost. Been looking for a forecast on that for a while now. Anyone any update on what the 12z is telling us. I have a few trips to make on 25/26th and if 6/7 or even 1-2 hours of snow is on the way I am staying in front of a warm fire with my bushmills.:)

I think your safe enough, according to the 12z GFS anyway. Your actually in the only area of the country likely to see wintry conditions St Stephens day, and even then probably only on the highest ground.

Flooding is very likely to be an issue from Sunday to Tuesday, particulary downstream from any areas that have snow cover at the moment. There looks to be no thaw to speak of until the rain arrives, but the thaw will set in very quickly with the rain and higher temps.

th3 s1aught3r

MT has updated forecast for Leinster this evening/tonight

http://www.irishweatheronline.com/2010/12/forecast-update-6pm-thur-23-dec-2010.html

Pangea

Well Evelyns forecast was interesting this evening ,she said that as far as the models went to till New Year that there would be no real tropical air so there would still be frosty nights etc.

opr

18z GFS upgrades potential for snow in Northern parts tommorow.



Opr

Birdnuts

opr wrote: »

18z GFS upgrades potential for snow in Northern parts tommorow.



Opr

Yeah - their appears to be something heading South off the West coast of Scotland right now according to the latest RADAR:)

irish1967

Where the heck did that come from?? Jeez. Another replan required.

Goldigga

Must of been an extra 4-5 inches has fallen in parts of Tallaght tonight. It was non stop most of e the day. im measuring nearly a foot of the stuff now......... and i have to be in work at 7am in the morning!!!

Wine Goddess

Goldigga wrote: »

Must of been an extra 4-5 inches has fallen in parts of Tallaght tonight. It was non stop most of e the day. im measuring nearly a foot of the stuff now......... and i have to be in work at 7am in the morning!!!

Agree - we have now got about 3 foot snow in total over the last 48 hours in Firhouse and JUST when I thought it had stopped for the night it started again.

Looks like more streamers on way on sat 24 but none on raintoday.......Hmmm

irish1967

Sat24 is satellite and shows cloud. Raintoday is radar which picks up precipitation. What sat24 is showing must be just cloud.

4Sheets

Not wrote: »

ME calling the St Stephens day event as snow means it will certaintly be rain.

They never said that..they said snow would eventually turn to rain

Not

4Sheets wrote: »

They never said that..they said snow would eventually turn to rain

Refer to post 1350. The quote of the Eagles mentioning of a 'serious snow event'. Granted before it eventually turns to rain. But that's as opposed to just a rain event. But that was then, and things change constantly.

200motels

I Have a funny feeling that this mild weather will stall, this cold will be hard to just push away and could hold on in the east and then push the mild weather back to where it came. As to what I base this on it's just a gut feeling, I've looked at most of the models and most say that it will get mild but some like the Australian model thinks the cold will win out.

mike65

The fact this thread has all but stalled tells me all I need to know.

irish1967

What are the models saying about the 26th? Warmer from west or SW? snow first then sleet then rain? How long will snow go on for if it snows?
I can't imagine 6 inches of hard compacted frozen snow vanishing in less than 2-3 days. Is the cold stall looking any more or less lightly??

TheMilkyPirate

mike65 wrote: »

The fact this thread has all but stalled tells me all I need to know.

10 posts since 9 o clock last night is hardly stalling now is it?

:rolleyes:

Birdnuts

irish1967 wrote: »

What are the models saying about the 26th? Warmer from west or SW? snow first then sleet then rain? How long will snow go on for if it snows?
I can't imagine 6 inches of hard compacted frozen snow vanishing in less than 2-3 days. Is the cold stall looking any more or less lightly??

According to the 06Z the warm air(8-10C by day) makes it into the whole of ireland by Tuesday while just over the irish sea temps stay close to freezing next week. Like MTC I have my doubts that it will be as cut and dried as that

mike65

The 26th looks like being the transition day, in the south and west it'll start to thaw but midlands/east will still be around freezing point by the looks of it. Monday will see possible double figures in the south/west and milder in the rest of country. The thaw could take several days to be fully effective (stand by for floods in Dublin)

Not

mike65 wrote: »

The fact this thread has all but stalled tells me all I need to know.

er.. um... it's Christmas ?

maquiladora

irish1967 wrote: »

Is the cold stall looking any more or less lightly??

I think MTC said there is only a slim chance of it happening now.

All the models I've looked at today show the cold losing the battle, and remember this is only two days away, not deep into FI....

Edit : What a negative and crap 4,000th post :P

nacho libre

maquiladora wrote: »

I think MTC said there is only a slim chance of it happening now.

All the models I've looked at today show the cold losing the battle, and remember this is only two days away, not deep into FI....

Edit : What a negative and crap 4,000th post :P

i hope this post come back to haunt you:p sometimes the models can get it wrong. i'm clutching at straws i know.
it's a pity that the Atlantic, even in a weakened state, will win out again a huge bank of cold air over us.

Pangea

maquiladora wrote: »

I think MTC said there is only a slim chance of it happening now.

All the models I've looked at today show the cold losing the battle, and remember this is only two days away, not deep into FI....

Edit : What a negative and crap 4,000th post :P

I dont know maquiladora, MTs forecast shows the cold will still going be lurking around.

M.T. Cranium wrote: »

Friday, 24 December, 2010
_


MONDAY (27th) ... Unless the model guidance proves entirely false, this should be the mildest day of this brief thaw, and with 10-15 mms of rain in some areas, could prove to be quite a wet day as snow begins to melt. With lots of snow still in place, ponding on roadways and in parking lots will be a problem in many areas. So will dense fog in rural areas. Highs may reach 7-10 C in most areas but 4-7 C over higher northern snow-covered areas.

OUTLOOK ... Higher pressure will rapidly build in from sources in the North Atlantic and Scandinavia. While this won't be a severe cold spell, if at least half the snow survives the thaw, the nights are likely to become very cold again, and some inversion fog will develop and remain in place all day inland. Expect highs around 3-5 C at maximum, possibly lower inland, and overnight lows in the -5 C range. This spell may last quite a while according to the models but there are also hints of a reload of severe winter weather, which you could estimate might return some time around 2-4 January or perhaps a bit later than that.


.

maquiladora

12Z UKMO looks a bit better at 48 hours for a chance of the precip to fall as snow for a while before turning to rain.


UKMO :



GFS :

mickger844posts

If only this was snow, looks like plenty of rain for the south.

Scubadevils

Out of interest (and hope!), does anyone know how far off the 82 snow was predicted or was it a surprise so to speak? - I presume the scenario then was similar to now in that there was cold weather that the atlantic attempted to shift unsuccessfully?

maquiladora

Scubadevils wrote: »

Out of interest (and hope!), does anyone know how far off the 82 snow was predicted or was it a surprise so to speak? - I presume the scenario then was similar to now in that there was cold weather that the atlantic attempted to shift unsuccessfully?

This was the forecast the day before the snow. Of course weather forecasting has come on a long way since then, but anyway...



And a press clipping



(Taken from an old thread)

mike65

Scubadevils wrote: »

Out of interest (and hope!), does anyone know how far off the 82 snow was predicted or was it a surprise so to speak? - I presume the scenario then was similar to now in that there was cold weather that the atlantic attempted to shift unsuccessfully?

This is worth a read -

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=6681&start=1

Scubadevils

Thanks, yeah I remember reading that before in another thread actually. So really they didn't see what was coming but I suppose the difference was that the easterly was only becoming established and meeting the front from the atlantic is bound to have massive potential - versus now a retreating easterly?

I know all of the models show the colder weather being pushed away, just seems to hard to imagine with the deep cold there is now... hopefully there are a few more twists to the coming days. And then of course Jan, Feb and March. Funny actually, I remember in many winters past clutching at straws in March in the hope of winter delivering before it moved on for another year - amazing to think we still have 3 months of potential.

dsmythy

mickger844posts wrote: »

If only this was snow, looks like plenty of rain for the south.

Right over Waterford 'no snow' City too