Model Output - General Discussion

[Jan 87]

Midday temps Sat-

Anyone want to throw the Marginal curve ball at me again-

http://www.wetterzentrale.de/pics/Rmgfs1384.gif

yes thats -3 MAX in the HIGH res @ 138.....

S

Yes, no point worrying about a breakdown beyond 168, when there is so much to focus right now.

[TEITS]

If this carries on the ridge from Greenland will be off the African coast.

Some bitter cold being shown on this run and quiet exceptional for mid Dec.

http://www.wetterzentrale.de/pics/Rtavn1741.png

Fax charts are very late tonight. I keep refreshing however!

[Geordiesnow]

A nice run regarding the Northerly potential with the cold front producing a lot of snow for some areas. Lots of showers for Northern and Western areas aswell.

But beware because shortwaves might come into play and we might also see other downgrades but i suppose it's something to keep an eye on.

Good news for cold fans is that there is no mild weather for a good old while either.

[damianslaw]

The ECM certainly isn't as good as the 0z run but the only reason for that is the huge Atlantic LP that has periodically also be shown as strong by the GFS, the actual jet pattern still looks pretty solid and there is still relative heights over Greenland which aren't bad.

If the LP was closer to the GFS 12z op run's strength then I suspect the 12z ECM would have looked quite a bit more interesting, however with such a big low there can be no doubt a breakdown would probably occur shortly after that chart...just in time for xmas.

As Steve said though I think the models still maybe somewhat progressive, its looking increasingly likely milder air will creep into the south but the north shows a lot more uncertainty with quite a few runs still cold at xmas day and this shows how close the pattern could turn out to be, I would not yet rule out a big xmas day snow event for at least the north...

Its very difficult at the moment to refrain from talking about what the models a re showing way beyond the reliable timeframe and the simple reason is Christmas Day - so perhaps I will excuse myself this time..

In response to your thoughts these are echoed by mine. Though most models are showing the atlantic firing into gear just in time for christmas, I very much doubt we will see it steamroller in on its SW-NE trajectory, the cold air will be very reluctant to loosen its grip, with heights remaining high to the north and more importantly over Greenland and still a combined negative NAO and AO the low is mostly likely to take a more southerly track and quite easily undercut the highs, the north would stay in the cold air and have a snowfest.. the teleconnections do not support such a low crashing through and bringing in SW airflow.

Anyhow back to the reliable timeframe, the ECM and UKMO look like they are prolonging the easterly a bit longer than the GFS and thereafter for the weekend all models are in agreement of a northerly plunge equalling very cold and snowy from Thursday onwards - great seasonal weather and a long long time since we have had such synoptics at this time of year.

[Nick L]

Getting into the teens by Sunday though...negative teens. Could be seeing some very cold temperatures going by the 18z:

http://charts.netweather.tv/gfsimages/gfs.20091213/18/168/ukmintemp.png

Maximums of -5c in the north on Sunday as well...

http://charts.netweather.tv/gfsimages/gfs.20091213/18/162/ukmaxtemp.png

[Bristawl Si]

The downbeat posts of some on here in the last 24 hours seem well misplaced on the evidence of tonight's 18Z.

Looking at Saturday and Sunday's forecast temps and possible snow this seems one hell of an upgrade to me. I think this cold spell will dig in. One of those that extends much longer than most would expect. That northerly seems extreme to me - maybe too extreme. One hell of a week+ coming up i feel.

[Tom D]

Some of the projected temps for N.England are incredible on the GFS, must be some sub -15s showing up for next weekend over night! Coupled with plenty of precipitation, there'll be feet of snow if this comes off!

http://charts.netweather.tv/gfsimages/gfs.20091213/18/168/ukmintemp.png

This run is astonishing, so much precipitation around, so much cold air, have never seen anything like it!

I actually do not believe it - FI has another easterly for us!! :o

Edited December 13, 2009 by Tommyd1258

[mountain shadow]

If the Northerly turns out like tonights 18z then we are in for a hell of a battering

next weekend that's for sure.

[Cloud 10]

The 18z out to 168.

If this run was to verify,most parts of the country will see some snow over the next 7 days as well as very low daytime temps.

We really are being spoilt at the moment with runs like these.!

[bluearmy]

shortwave out of the gulf of mexico behaves differently and we have trough disruption off the eastern seaboard - different fi likely

[Upgrade]

If this carries on the ridge from Greenland will be off the African coast.

Some bitter cold being shown on this run and quiet exceptional for mid Dec.

very impressive. i can hardly believe these charts are coming into a realistic timeframe ; though everything seems to be matching up in a textbook way for a prolonged cold spell.

[January Snowstorm]

An astonishing run yet again

Truly amazing runs

[morfius]

Looks like a possible reload in FI with another high ridging in from the south, combining with the greenie again!!

The cold is extended past christmas day this time!!

Edited December 13, 2009 by morfius

[Jan 87]

http://www.wetterzentrale.de/pics/Rtavn2761.png

Very different FI. Another High builds and keeps it cold over Xmas.

[benb]

Truly extreme stuff (in my experience) on this run- bits and pieces of snow Thurs/ Fri, then a what's looking like a bitterly cold and very snowy weekend.

The best bit is that the models, with a couple of blips, have been, IMO, very consistent with the pattern from this time last week. Thurs/Fri has always been when the action was really going to start. Now we're able to fill in a little more of the detail, it's going to get even more exciting!

Am I dreaming?

[John Snow]

Massive massive upgrades for the north, 3-4ft of snow across huge swathes of the north, north east and scotland if the 18z comes off

Less good down here for snow but confident of a little bit

[Jan 87]

http://www.wetterzentrale.de/pics/Rtavn3001.png

LOL! A 1963 type of run. We can go to bed happy

[stratty]

The 18z is a phenominal run for the whole country for bitter snowy weather - reminding me very much of 1981! Not good if you want to travel before Christmas! Can this country cope with such an event?!

[kold weather]

Yet another stunning run, this time the whole lot is an upgrade...

The easterly is not really a big issue BUT instead we have a pretty interesting trough set-up over the SE which promotes quite a decent amount of precip, then we see a stunningly cold day on Saturday as the cold air comes down and cloud comes down from the north and keeps maxes surpressed, followed by snow. Then the whole lot eventually reloads...quite a mental run!

[Cecil Hogmanay Melchett]

18Z leaves me utterly gobsmacked.Scotland and the North would have literally feet of snow if that came off.

Unstable Artic Northerly with snow piling down the country.

It cant and wont get any better than 18z.

[Gavin P]

Classic Pub Run! :o

Inches and inches of snow falling over the weekend and early next week, then high pressure builds in and preserves all that lovely snow cover for Christmas Day!

[John Snow]

This will paralyse the country, transport system grinding to a halt, loss of power in many areas through sheer weight of severe snowfall, panic buying in the shops from midweek, 3/4 ft of snow with 20ft drifts, food shortages, while this level of snow is great for some it will paralyse Britain

[swfc]

very big change on this run regarding the atlantic coming in.????.All to play for i reckon and anything at the moment given the blocking pattern is possible.

Edited December 13, 2009 by swfc

[Nick L]

This will paralyse the country, transport system grinding to a halt, loss of power in many areas through sheer weight of severe snowfall, panic buying in the shops from midweek, 3/4 ft of snow with 20ft drifts, food shortages, while this level of snow is great for some it will paralyse Britain

If I had a pound for every time somebody said this after seeing one run I would be a very rich person...

[jam]

This will paralyse the country, transport system grinding to a halt, loss of power in many areas through sheer weight of severe snowfall, panic buying in the shops from midweek, 3/4 ft of snow with 20ft drifts, food shortages, while this level of snow is great for some it will paralyse Britain

Ah but the great thing is we get to panic buy first!