Winter Model Discussion 12Z 22/1/13 onwards.

[Jason M]

There are some decent ensembles to be fair. Bit more suggestion of the lesser spotted Greenland High :-)

Jason

[That ECM]

The talk of average/good/bad is a matter of opinion but has little to do with model discussion I would suggest. For that matter t240 on ECM offers hope, it would be nice to see this develope.

[shotski]

Anyone looking for cold from this chart are straw clutching, lets call it a day untill next winter

[Eskimo]

Anyone looking for cold from this chart are straw clutching, lets call it a day untill next winter

Erm...lets not.

Some glimmer of hope at 240 sees the low just south of the UK, perhaps the 2nd is that start of another spell of cold weather? To the 18z!

[Cheese Rice]

Judging by the negative undertones on here It seems some have ridiculously high expectations, we are nearing the end of a significant cold spell with some places recording over ten consecutive ice days. The cold spell for many areas will come to an abrupt end on Sunday with a return to average temperatures. This takes us to the 27th where we see a raging PV forming over Greenland. Or at least that's how it would appear, yet there's very week heights over the region stopping low pressure from tracking right over, so while the PV is in full swing it's not in the most unfavourable of positions.

If we look at T144 across the main models we see the UKMO & ECM both showing small height rises, yes nothing significant but this is a key ingredient if we want to see a.)southerly tracking jet b.)low pressure deflected of the Southern tip of Iceland.

http://www.meteociel...44-21.GIF?23-18

http://www.meteociel...H1-144.GIF?23-0

We then look at the latter output of the ECM which -arguably- would mirror the UKMO post T144 in this instance.

http://www.meteociel...H1-240.GIF?23-0

Very encouraging to see increased heights and southerly tracking low pressures. Yes it's no raging Greenland high but that's largely irrelevant as this week shows.

Back to my earlier point we've gone from Zonal starting on the 27th to a much more favorable prognosis on the 31st, that's four days of mild weather.

Perspective!

Edited January 23, 2013 by Cheese Rice

[Snowman.]

Wow im amazed at the negativity on here especially from some members on here.

Just chill and wait for next week by then we should get have a MUCH clearer picture on how things evolve. We have reason to believe that we COULD see height rises north. I'm also surprised that many have put faith into what the MetO and the models are saying that's 15 days away we all know what changes in 15 days?

I'm looking forward to the Mild weather coming this weekend for ever how long it lasts I get bored otherwise unless I'm under 2 feet of snow.

[nick sussex]

If we think back to what the ECM was showing a few days back its now slowly moved away from the raging PV and totally flat upstream pattern.

We now have the possible saviour low showing at 144 in the USA! The ECM and UKMO both agree on this, some of the comments in here in recent days are more born out of possible snow melt trauma which often happens when a cold spell is drawing to a close!

[Gibby]

Good evening folks. Here is the evening look at the changes that are soon to take place in the weather over the coming two weeks from the 12z output of GFS, UKMO and ECM for today Wednesday January 23rd 2013.

All models show a change in the weather soon. Tonight will see a cloudy and cold night for most with some snow showers continuing for a while in Southern England before they die out overnight. Elsewhere a few clear spells could develop later with a sharp frost as well as freezing fog patches as pressure gently rises from the North. Tomorrow will probably see a dry day for all with the stubborn grey cloud of recent days breaking to give some sunny spells through the day. It will remain cold though with only a slow thaw in the afternoon. After a frost tomorrow night a trough of Low pressure will approach the West later on Friday with a spell of heavy rain crossing West to East over the UK. The rain will fall as snow for a time, longest in more Northern and Eastern areas where another good 5-15cm is possible in strong winds. Overnight the snow will turn to rain and clear from the West with Saturday being a quieter day with normal temperatures with a continuing thaw of lying snow. Later in the day SW winds will become strong with heavy rain sweeping East over the UK followed by blustery winds and squally showers on Sunday with some snow showers still on high ground in the North.

GFS then moves into next week with strong to gale SW winds and rain sweeping back NE on Monday followed by a broad SW flow with further rain at times in the North and West while the South and East see much less rain and longer dry spells. this weather type is shown to persist until the weekend when a band of heavy rain crosses the UK in developing strong Westerly winds. By the end of Fi following a series of very deep depressions, gale force winds and heavy rain a change is shown to cold and wintry weather briefly at the end of FI as the deep Lows move away East and winds swing NNE.

The GFS Ensembles show a warm up guaranteed now at the weekend with a spell of unsettled weather thereafter with rain at times shown at all locations. Later the uppers gradually fall back to nearer normal values though there is no definitive indication or trend of any return to cold from anything in the GFS output tonight.

The Jet Stream shows the flow to the South of the UK currently but soon to swing its axis to run SW to NE over the UK to Norway in a weeks time.

UKMO for midday on Tuesday shows a strong SW flow over the UK in association with Low pressure out to the NW. There will be spells of rain for all, heaviest in the North and West in temperatures well up to the seasonal normal or above in the sheltered East.

ECM finally shows a mild spell next week too in strong SW winds with spells of rain for many. Late in the run the jet flow appears to be moving South again as pressure rises over Greenland with a renewed surge of cold air waiting in the wings for the UK after a very unsettled day 10.

In Summary all models are in agreeance that the weather is soon to turn milder with a rapid thaw and some heavy rain to aid the process over the weekend. GFS then shows a period of sustained milder and sometimes stormy weather while ECM shows rising pressure to the NW with cold weather soon to return to the UK beyond day 10. It will be interesting to see whether this trend is reflected in the ECM Ensembles later and extended to future runs taking on board GFS too. If this trend to cold weather occurs and is extended into the here and now remember it was ECM who spotted it first. It will save a lot of debate over which model spotted it first later. It's a long wait and ride to get to it though.

[Summer Sun]

GEM follows the other models tonight by going zonal and eventually mild for the start of next week

[bluearmy]

so thats gem 00z , ecm 12z, jma 12z all showing something of interest re the nwp maybe deciding that its zonal train may not be quite the solution for early feb and that splitting vortex and arctic height rises in conjunction with some to the nw may be something to watch over the next few days.

Edited January 23, 2013 by bluearmy

[chionomaniac]

I was wrong this is even worse.

http://modeles.meteo...nh-0-240.png?12

Very odd because historically Feb is the most blocked months out of all the winter months and yet despite the SSW the models are predicting a zonal even possibly stormy spell of weather at the moment.

Again Deja Vu as this is looking like a repeat of what happened last year. Really does make you think back to how extraordinary those Greenland HP's were in Dec 2009, 2010 without the aid of a SSW!

What is really odd, is that you are looking at the most unreliable model at day 10 - well into FI, that is showing a zonal chart for the 2nd of Feb, and trying to suggest that this FI chart (from that unreliable model) is somehow representative to the whole blocking pattern for the next 26 days of that month (never mind that it is probably totally incorrect for the 2nd Feb)?

Hmmm.

[nick sussex]

Here cometh the possible saviour low:

If you're looking for a dramatic quick turnaround then this could provide it!

This runs east and deepens, it engages the PV lobe in northern Canada, this will pull the PV further to the nw.

If we can get enough amplification this can then help deliver some pressure rise to the ne

However I still think we won't manage a proper Greenland high but more likely to the ne, we may well be back to similar synoptics that we've just seen.

Anyway thats my glass half full view.

We'll see over the next few days, so keep an eye on that low, it has to verify and deepen if you want a quickish return to colder conditions.

Edited January 23, 2013 by nick sussex

[Weather-history]

Very surprised you of all people have said.

Its very simple really. Why do you think its commonly said that snow is more likely during March than Dec? This is because blocking becomes more frequent during late winter than early winter because the strength of the PV & PFJ generally weaken during late winter compared to early.

This may be so but there is nothing very odd by a zonal February, which is my point. Such as 1990, 1995, 1997, 1999, 2000, 2002, 2011

Edited January 23, 2013 by Weather-history

[BLAST FROM THE PAST]

If you are looking for cold this is about the most inverse chart you could get -

http://www.meteociel...H1-144.GIF?23-0

Upper low over iceland & heights stretched all the way from Spain through europe out to russia- no troughs digging through that-

Perhaps some misplaced optimism today- the ECM day 10-15 ensembles have moved to a Mean along the average line & the spread fairly consistent either side, no clear signal for cold to return. Average joe at best.

The mild weather will greet us into feb with a very low probability of change before then- possibly lower than 5%.-

So that will usher in an above average Dec & with Jan aiming at high 3's to low 4s at best an average month within 0.5 degree either side.

8 weeks down, & this winter has average written all over it. It will take something exceptional to pull it out of the bag- & theres nothing within ANY indicator that shows that something big on the cold front is coming, however that doesnt negate the fact that something could crop up as we go through Feb to sway the overall averageness of Winter- all be it with Jan showing a fair chunk of weather at either ends of the spectrum- including 10-12 days of very cold air for the UK.

S

So to date a descending winter? I think there is some pain to be had with the cold spell ending, but the hemsipheris pattern is shifting. Your judgement re being greeted by mild into Feb looks about right Steve, but it ain't been that bad, and there are still chances. If we had been mild all the way up to now with the mild ahead I'd be worried...we must accept the change ahead BUT it could be and have been a lot worse. I think the ECM 12z in bigger picture following the 00z is offering hope through this period as we get to the other side.....say around 4th feb?

BFTP

[bradymk]

Latest JMA long range ensembles updated on Friday show a deep trough to our west in week 2 with milder south westerly and westerly winds. Week 3 and 4 show a change with strong +ve heights to our North west with low heights to our north. Sorry no charts, on mobile but interesting update from JMA with the week 3 and 4 charts forecasting between 4th and 18th Feb period. The Korean long range forecast also updated shows interest for cold weather with strong +ve heights to our north and north west with a trough to the east. Korean shows coldest period mid to late February. CFS also starting to come on board with this also. Long range models arent the most accurate but interestingly they all agree with regards to mid atlantic ridges/low heights to our East.

[shotski]

Latest JMA long range ensembles updated on Friday show a deep trough to our west in week 2 with milder south westerly and westerly winds. Week 3 and 4 show a change with strong +ve heights to our North west with low heights to our north. Sorry no charts, on mobile but interesting update from JMA with the week 3 and 4 charts forecasting between 4th and 18th Feb period. The Korean long range forecast also updated shows interest for cold weather with strong +ve heights to our north and north west with a trough to the east. Korean shows coldest period mid to late February. CFS also starting to come on board with this also. Long range models arent the most accurate but interestingly they all agree with regards to mid atlantic ridges/low heights to our East.

got some a couple of days old

[Methuselah]

Please use this thread for moans & ramps etc...

Missing posts have only been moved...

[stewfox]

8 weeks down, & this winter has average written all over it. It will take something exceptional to pull it out of the bag- & theres nothing within ANY indicator that shows that something big on the cold front is coming, however that doesnt negate the fact that something could crop up as we go through Feb to sway the overall averageness of Winter- all be it with Jan showing a fair chunk of weather at either ends of the spectrum- including 10-12 days of very cold air for the UK.

S

I will take 10 near ice days a few heavy heavy snow falls for my 'average' any winter. Came home to more heavy heavy snow.

I appreciate a zonal pattern is easier to forecast as its defacto situation but why do T384 charts become reality when last week FI was T72.

Charts wlll always chop and change and FI for our little island will always be max T168 and I can live with that.

[Summer Sun]

The jamstec model has now updated for January for the period of March to May and it has precipitation below normal for the period and temperatures above normal

[Frosty.]

The biggest worry next week is flooding, it looks relatively mild, wet and windy from sunday onwards through most of next week with all the snowmelt and heavy rain it could be a period of major flooding like it was before christmas except without the snowmelt, worrying times ahead. The Ecm 12z has signs of something colder towards T+240, the Gfs 12z shows signs of a more nw/se angled jet later in FI so there is hope as we go into feb of some wintry charts getting closer but next week looks unsettled with a lot of rain and swly to wly gales or severe gales, especially towards nw britain, also cold enough for hill snow in the north away from the milder sectors. At least the atlantic looks active enough to send us through some rapidly changing weather with not much sign of anything settled as such, maybe trending drier towards the southeast of the uk eventually with a risk of frost at times but further northwest looks low pressure dominated.

[Ian Brown]

I was wrong this is even worse.

http://modeles.meteo...nh-0-240.png?12

Very odd because historically Feb is the most blocked months out of all the winter months and yet despite the SSW the models are predicting a zonal even possibly stormy spell of weather at the moment.

Again Deja Vu as this is looking like a repeat of what happened last year. Really does make you think back to how extraordinary those Greenland HP's were in Dec 2009, 2010 without the aid of a SSW!

Dave, most out of character for you to be posting zonal charts at day 10 !

February can be the most inactive Atlantic month but we know that equally it can be near springlike if the synoptics fall that way. I'm quite confident that we will start to see the NWP showing mid-Atlantic height rises as the jet amplifies over the US over the coming days and we will see where we go from there.

[Snowmad79]

People complain about others being negative - whenever I try to explain politely why, my posts get removed - I think there is something wrong here.

Because you need to be posting in relation to model output and not justifying so called negativity. Just because someone posts about not seeing any quick return to cold based on model output does not mean they are being negative. A lot of people on here know very well a bad pattern when they see one having spent many years following the models. That said, everyone does need to be "open minded" what ever way output goes.

Try and stick with model output and your posts won't get deleted.

As for the models. Indeed, the ECM now showing signs of what the GFS was initially showing in mega FI with regards to possible height rises to the north. Could well end up similar to the recent setup as Nick S suggests as we head into February. At least we have something colder to watch our for, even if it does turn out to be zonal. No way I am saying it will, especially after the recent palaver.

[mcweather]

If you are looking for cold this is about the most inverse chart you could get -

http://www.meteociel...H1-144.GIF?23-0

Upper low over iceland & heights stretched all the way from Spain through europe out to russia- no troughs digging through that-

Perhaps some misplaced optimism today- the ECM day 10-15 ensembles have moved to a Mean along the average line & the spread fairly consistent either side, no clear signal for cold to return. Average joe at best.

The mild weather will greet us into feb with a very low probability of change before then- possibly lower than 5%.-

So that will usher in an above average Dec & with Jan aiming at high 3's to low 4s at best an average month within 0.5 degree either side.

8 weeks down, & this winter has average written all over it. It will take something exceptional to pull it out of the bag- & theres nothing within ANY indicator that shows that something big on the cold front is coming, however that doesnt negate the fact that something could crop up as we go through Feb to sway the overall averageness of Winter- all be it with Jan showing a fair chunk of weather at either ends of the spectrum- including 10-12 days of very cold air for the UK.

S

Which just goes to show Steve that even an average winter can produce blizzards and deep lying snow for many areas of the UK. Even down here in low lying rural coastal Dorset. I've had two blizzards and nearly a week of snow cover albeit melting a little bit each day.

I don't feel too worried about Feb there are enough options in the GFS output to keep the interest going including a few Greenland highs and even tonights ECM hints at some similar interest later on.

[Frosty.]

8 weeks down, & this winter has average written all over it. It will take something exceptional to pull it out of the bag- & theres nothing within ANY indicator that shows that something big on the cold front is coming, however that doesnt negate the fact that something could crop up as we go through Feb to sway the overall averageness of Winter- all be it with Jan showing a fair chunk of weather at either ends of the spectrum- including 10-12 days of very cold air for the UK.

S

Yes something cold will crop up, every day there should be some sign in the models somewhere of our next cold shot, we just have to accept the cold is leaving us but only for a while and it will be back in some form or another before mid feb and don't rule out another freeze but I noticed the extended meto not as wintry as it was but that can change. A very active period coming up with the last significant snow on friday for at least 10 days+

[cold snap]

http://null/TWO/ensembles/#ECMshort

ECM ens

Not much to go on really, no defining cold trend evident

Edited January 23, 2013 by cold snap