Model Output Discussion 12z 04/12/2012

[Dave Kightley]

it happened in 2010 , you can see it on the chart below :

yeah i can remember that but not sure if it brought snow or not???

[Panayiotis]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

Well if you have been following the 12z you might have seen the 'milder' option later in FI, and maybe this the Metoffice just 'sitting on the fence', however from background signals and from many knowledgeable people on here this may be unlikely as this low relates to zonal weather.

[suffolkboy_]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

Welcome to the forum! I know many people read but don't post...so well done on coming out of the shadows and joining in the fun!

The first scenario shown on that video is what many are getting excited about on there, a large high pressure system over Scandanvia bringing an easterly (or generally from that direction, NE, SE maybe).

The second where he talks about it maybe being milder is if the cold air doesn't reach as far west as the UK. We would be mild whereas much of Europe would be in the freezer.

Looking odds on that Europe will see some significantly cold weather, but for the UK as ever, if could mean we are right on the edge of the cold. Sometimes we can sit in the cold for a day or two, only for a low pressure system to "bump" into the cold pool over the UK, warming us temporarily. It's then a battle between mild and cold. These sorts of set-ups can bring large dumpings of snow as 1947 showed. But you need a good bit of luck to see that!

[Jayces]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

It's so they can tell us about cold without committing to it so they aren't left with egg on their face but at the same time can say well we did say it might happen ;-)

[snowmadchrisuk]

yeah i can remember that but not sure if it brought snow or not???

it brought very heavy snow to South West England (4 Days worth) which eventually spread up into the Midlands, it was a battle ground situation with Cold air winning

[mickpips]

Excellent explanation of the prospects and probability / potential next week 41/51 ECMWF runs suggest an Easterly flow. http://www.bbc.co.uk/paulhudson

[kold weather]

Some impressive GFS ensembles it has to be said, though there are alot of different solutions still on the table it has to be said.

The control run is just a jaw-dropper, never seen such a perfect case of reverse zonality as the 180-192hrs chart, madness!

[snowking]

JMA up to +84

Slightly more amplified and better heights around Greenland compared to yesterdays 12z. Icelandic SW still basically identical in track

SK

[Buriedundersnow]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

there just covering themselves incase it doesnt happen

[IDO]

The ensembles for the GFS 12z :

http://modeles.meteo...ndres&runpara=0

The op was a mild option from about the 15th. At the end of FI good clustering for 850s between -5 and -10c. Solid support for most of next week to be very cold & dryish(?) and only about 15-20% support for the Atlantic to enter the fray a la UKMO worries.

However this cold evolution when forecast last week by GFS, were showing as cold op outliers. Lets hope they haven't seen a changing pattern, and we will not get more of these milder ops. The 18z tonight is important as is the ECM.

Edited December 5, 2012 by i'm dreaming of...

[Skeggy Winter Storm]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk/weather/features/20618018 they seem to think that it may turn milder .

he's just saying theres two ways it could go

[ITSY]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

It's a good video IMO. not discounting options and making public aware of snowy potential. I should hope by this weekend we know what way it will swing, but it is, as it stands, more likely to be cold.

[West Sussex Kate]

yeah i can remember that but not sure if it brought snow or not???

Hi Dave, this is what happened:

http://www.dailymail.co.uk/news/article-1339149/Big-freeze-Temperatures-plummet-10C-bringing-travel-chaos-Britain.html

[london-snow]

The ensembles for the GFS 12z :

http://modeles.meteo...ndres&runpara=0

The op was a mild option from about the 15th. At the end of FI good clustering for 850s between -5 and -10c. Solid support for most of next week to be very cold & dryish(?) and only about 15-20% support for the Atlantic to enter the fray a la UKMO worries.

It's all good signs though, Once we get the pattern established the flow can also set off showers or longer forms of snow generated from the eastern coasts. These can and tend to travel well inland. Would not also rule out the possibility of streamers setting up but that is all to be decided in the future. The general pattern is excellent.

[fergieweather]

It's a good video IMO. not discounting options and making public aware of snowy potential. I should hope by this weekend we know what way it will swing, but it is, as it stands, more likely to be cold.

That's precisely our rationale with it until we see proper grasp on developments into early next week. We can't afford to ramp easterly until a clear done deal.

[london-snow]

All eyes down and hope that the ECM follows suite and delivers a great run..

[Damp and dreary]

yeah i can remember that but not sure if it brought snow or not???

Surely this was during the 'Coldest, snowiest December period for 100 years' Me think sit provided plenty of snow, certainly for the vast majority of the British isles

Looks like i was beaten to the answer by a fair few others!

Edited December 5, 2012 by jasonuk

[ITSY]

ECM seems to be about 12 hours ahead of where it should be from the last run, which looks like an improvement to me. It's the 96-144 frames that are crucial, with the latter either Beasterlies or dullness...I have my bets

[Dave Kightley]

Surely this was during the 'Coldest, snowiest December period for 100 years' Me think sit provided plenty of snow, certainly for the vast majority of the British isles

I was talking about the Polar Vortex displaced over us... I know about all the snow. Just if it did from that chart Edited December 5, 2012 by Dave Kightley

[West Sussex Kate]

We can't afford to ramp easterly until a clear done deal.

Okay won't ramp easterly just yet!

[Severe Siberian icy blast]

Hi all , Iv looked at the mods for tomorrow , and I can't help thinking the bbc are underestimating the snow potential for England tomorrow, even with the warmer uppers its stil -3/-4 up there, with low surface temps, and low due points , does to me look a poss snow to rain to snow , or snow on high ground away from the far southwest and south, any thoughts ?

[ITSY]

Hi all , Iv looked at the mods for tomorrow , and I can't help thinking the bbc are underestimating the snow potential for England tomorrow, even with the warmer uppers its stil -3/-4 up there, with low surface temps, and low due points , does to me look a poss snow to rain to snow , or snow on high ground away from the far southwest and south, any thoughts ?

I agree, but then they know more than me!

[Methuselah]

HI all, my very first post and have been watching and learning models since last october, been a great journey so far and im fascinated with posts you all put up on here and how `the cookie might crumble` one way or another... i have been keeping a close eye on the trend that is setting up for next week and its looking pretty cold from a model point of view..... However could some one explain why the met office have posted this on the bbc weather website not just 20 minutes ago ... http://www.bbc.co.uk...atures/20618018 they seem to think that it may turn milder .

Welcome to the forum, Bryan...

Why? Because Easterly regimes are notoriously hard to predict...And, in any case, it's always better to acknowledge the 'pear-shaped' scenario...

[Matty M]

@ 96hrs, the express awaits.. where it will take us, what we will see, its duration unknown.

But it is now likely, that we will be able to board.

[nick sussex]

The ECM not backing the UKMO over America at 96hrs, the low is likely to develop similarly to the GFS.