Model Output Discussion 29th December - Into mid-Winter.

[jethro]

If epic cold weather coming from the east is a beasterly, does that make wet weather from the west a weesterly?

[Weathizard]

UKMO 144 gives us some hope! It's now the saviour at t144 as to my rather tired eyes the GFS is a pretty dire outlook! The slug high is staying put if we trust the GFS!! 

Anyone got any salt?

Edited January 1, 2017 by Weathizard

[Scandinavian High.]

Gfs looks interesting later on way in f1 but won't happen .?

Edited January 1, 2017 by abbie123

[knocker]

The GEFS anomalies are quite interesting this morning IMO. A continued intensification of the Canadian vortex with Siberian lobe, the weakening of the Aleutian ridge until it disappears and the Atlantic becoming more zonal with far less amplification. There was a hint of this towards the end of the runs last night. Need to hold fire for a while to see whether the EPS is like minded. Meanwhile in the earlier time frame little change with strong anomalies in the Atlantic albeit the ridge flatter.

Back to the specifics this morning. All of the UK is in the colder air by tomorrow and the trough slides south to the east on Wednesday briefly bringing some stronger winds along the eastern half of the country as the surface wind veers northerly

Thereafter the usual interplay between the high pressure and the energy shooting out upstream with the latter winning much of the battle with a very strong SW jet compressing the ridging which leaves the UK with a N/S split weather wise as systems track SE impacting the NW/N of the country with the south remaining dry. This is tending to pay homage to the GEFS

A quick summation.

Initially the high pressure is generally in charge with the weather remaining dry and temps around average but towards the latter part of the ten day period the Atlantic pushes in with strengthening winds from the W/NW with outbreaks of rain. more likely to effect the NW.

Edited January 1, 2017 by knocker

[Seasonality]

Has GFS had a few last night?  Atlantic heights and an easterly return in FI.

[Polar Maritime]

Happy New Year to everyone here in the MOD, The GFS this year is back with a very cold N/NEly flow into Wk2. Who'd a thought..

 

 

Edited January 1, 2017 by Polar Maritime

[knocker]

The ecm keeps to the general theme of the GFS, perhaps the HP slightly more influential, but incursions occurring up north.

[IDO]

Again the GFS showing us part of the pattern of the Winter with a zonal spell mixed in the play book. The PV remains mobile  as it has a couple of times this winter will move to the north of the UK on this run. So HP in some guise from D2 to around D8, then the vortex drains away from the Canadian side on its slow journey back to the Siberian region. Heights then rebuild in the Atlantic and the pattern continues.

The signal has been mobility of the PV from Siberia to NE Canada for a few days with no signal after it gets there. This is now suggesting the next path of the PV mobility. So potential for some cold air in the mid-latitude as that occurs, but that needs tightening up on in the next few days as it is from D11. ECM not as progressive with the pattern but on the same page:

D10 

With respect to the second northerly, that was dead yesterday, but ECM moves it east further still and the GFS op it doesn't really happen (flatter pattern):

UKMO appear to have moved towards the GFS with a wedge of HP in Europe at D6 which will also flatten the pattern in the next frames.

So in the reliable, just-below average temps from a SE perspective, nothing wintry likely, but feeling cold I would expect. No point going further than D9 until we see if the new trend is a runner, as with new signals the GFS tends to over play its hand, and the op and control are showing the coldest solutions, highlighting this:

 

 

 

Edited January 1, 2017 by IDO

[carinthian]

Happy NY from Austria. Still a lot of water under the bridge till next weekend. The Mid week synoptic forecast chart from UKMO looks cold for many in Euroland and including The British Isles. The extended charts to 120t chart keep you lot under settled cold wintry conditions for most of next week. By weekend we could see a better chance of snow in week 2 for you hopefully. What I am saying , not all is lost. Much better charts than last winters full throttle zonal charts with not even a frost in sight for you guys. The general pattern remains blocked and your time will come.

 

 

C

Edited January 1, 2017 by carinthian

[radiohead]

A very disappointing ECM (unless you live in Eastern/Southeastern Europe). This says it all really.

The GFS offers a glimmer of hope deep in FI, but it's colder than all 20 ensembles on the 16th.

 

Edited January 1, 2017 by radiohead

[bluearmy]

Looking more an more like we needed to get that blocking established before the next movement of the p/v fired the jet and attempted to flatten it. now we see it much too easy to send most into the northern arm and you can cross the following off your list for the locale of the upper ridge

iceland

scandi

leaving sceuro, UK, east Atlantic, euruk, and perhaps we should add Azores and euro just in case!

eps due out shortly and what I shall be looking for is the propensity to maintain the w euro heights for longer (as the Southern arm into Iberia may well be starved ) creating a general nw/se jet flow into e Europe which really wouldn't be of much wintry use to most of the uk. 

Even the gem ens are now clear on a decent neg AO establishing for week 2. (Making cross model ens agreement) are we destined to miss out again on a further draining of low temps into the mid lats? 

Edited January 1, 2017 by bluearmy

[winterof79]

All to play for.HNY

[Nouska]

Wishing my weather community friends a very good New Year.

GFS decides to kick 2017 off in style - a swift canter through most of the DECIDER weather regimes one could expect over the course of the year.

http://www.metoffice.gov.uk/research/news/2016/new-weather-patterns-for-uk-and-europe

It'll get the right one for us soon - have the faith.

[Summer Sun]

A lot of dry weather to be had over the next 10 day's according to ECM if it's proper cold you want eastern Europe is the place to be

Edited January 1, 2017 by Summer Sun

[Seasonality]

44 minutes ago, radiohead said:

A very disappointing ECM (unless you live in Eastern/Southeastern Europe). This says it all really.

The GFS offers a glimmer of hope deep in FI, but it's colder than all 20 ensembles on the 16th.

 

Minus double digits if that verifies. 

[knocker]

The ext EPS not anywhere near as keen on zonality as the GEFS and retains positive anomalies and a ridge to the west of the UK and thus the latter still under the umbrella of a quite cold NW upper flow. I'm inclined to go along with this at moment keeping in mind the latest NOAA

Edited January 1, 2017 by knocker

[mulzy]

8 minutes ago, knocker said:

The ext EPS not anywhere near as keen on zonality as the GEFS and retains positive anomalies and a ridge to the west of the UK and thus the latter still under the umbrella of a quite cold NW upper flow. I'm inclined to go along with this at moment keeping in mind the latest NOAA

Yes, the extended eps far better than I anticipated.   Deep upper trough over Central/Eastern Europe and upper ridge in the mid-Atlantic.  The 850s for day 12-15 in London are circa -4 (which is pretty decent at that range).

[bluearmy]

14 minutes ago, knocker said:

The ext EPS not anywhere near as keen on zonality as the GEFS and retains positive anomalies and a ridge to the west of the UK and thus the latter still under the umbrella of a quite cold NW upper flow. I'm inclined to go along with this at moment keeping in mind the latest NOAA

notwithstanding the disappointment on here for the vast majority of the failure of the retrogression, the cross model extended ens in general point to a very cold European outlook and the sceuro low anomoly backing further west to encompass the uk. Retrogression of the Euro heights on the eps look more likely on the 00z run, initially to wsw of the uk allowing that nw/se axis on the jet but increasingly wnw which allows the trough to back west. 

the GEPS  and GEFS this morning on the same page in their 11-16 dayers and the eps 10/15 almost the same. 

 

 

The GFS operational probably not too far away from what seems on the table if you move it a few hundred miles north in the mid term and then ignore the over amplification post T300. (Which could of course happen but wont  show on a mean output at that range).

so the Atlantic high anomoly dumbells around reacting to the upstream forcing and allows systems to traverse around the top and dive to our se. The upper trough slowly backing west in time to give a cold cyclonic European pattern by end week 2. No doubt Matt will avail twitter as to the clustering on the eps. 

 

Edited January 1, 2017 by bluearmy

[KTtom]

All looks fairly positive from my point of view, yes, the easterly looks dead in the water, however deep cold is now seeping south into Europe,  with all operationals hinting that pressure will rise again in the Atlantic a good chance of further northerly blasts increasing in intensity especially mid month would be my estimate.

[TEITS]

Have to laugh at the GEFS ensembles. Just been looking at the 850hpa mean for Friday runs and compared with todays 0Z. For the 8th Jan we have seen a rise of around 10C!!

Still I do agree with the positive vibe on here because it looks as though we might be chasing the next cold spell very soon. Only difference is thankfully this is more likely from the NW/N than the E.

[Singularity]

This low off N. America in 6-7 days time is really bugging me. Once the models had it interacting with the Azores Low and acting as a trigger for a temporary ridge toward Greenland which allowed LP to dive well south through C/E Europe and HP to ridge over the top i.e. to through N. Scandinavia. Now they're firing the N. American low over the block, GFS with outrageous gusto while ECM is more restrained. UKMO is about halfway between those two models (back to normal for that model then!).

It's a troublemaker because it doesn't gain much of an identity until 6 days time, meaning there's a lot of scope for error with the track and timing of this feature - which means the case for calling a more mobile spell is as precarious as that for calling a continued blocked scenario (which by the way includes the form horse of recent weeks; UK blocking).

 

The more mobile outcome sees the main thrust of the Canadian vortex seeking to escape to Siberia while the remnants are retrogressed by the major Pacific ridge/block. That pull west taking place across N. America is the reason for GFS turning back to a northerly type theme in the 10-16 day range. So we see that something's still up and the vortex isn't looking to organise and 'plow the road', but we've little clear indication as to how things will actually come together, if much at all prior to the potential upward kick in GLAAM via tropical forcing that Tamara has recently alluded to. The EC ensembles have recently picked up on this signal for about two weeks from now, but the other models show little interest at this point in time.

[stodge]

Morning all

Happy New Year to everyone - for me, winter model watching doesn't start until mid-January and continues until mid-March.

As a clue, my birthday is two weeks today - the number of years I can recall snow on the ground on my birthday can be counted on the figures of one hand (and I'm the wrong side of 50).

The failure of the latest cold shots were, as we've seen the last two or three winters, the resolute failure of the PV to move from Greenland/Davis Strait territory. The forecast retrogression was based around the PV core shifting further west into Canada allowing either heights over Greenland or over Scandinavia.

This morning, there are still "hints in FI" of the PV breaking down or re-locating but as soon as we come into hi-res, the PV is stuck fast and all our dream northerlies or easterlies come to nothing and the northern arm means the best we get is MLB.

For me to get excited about a cold spell, I'd want to see the PV move or dissipate within T+96 - this is the fail point for the current cold spell:

The PV is re-assembling around the Davis Strait squeezing out the Greenland heights and the northern arm of the jet is too strong to prevent the HP sinking over us.

Anyway, lots of winter still to come and enough straws in the wind to suggest we may get "something" and let's be fair, most people remember a winter for 10-14 days of severe weather at most rather than 90 days of cool weather. 2010 is remembered because of December - who remembers Jan and Feb 2011 ? If you want 90 days of cold, you won't find it in the British Isles between December and the end of February.

[Man With Beard]

Having seen the 00Zs, it's time for my obituary on the "easterly".

The new ECM's consistency in December have me confidence to believe in it for the height rises to and beyond the UK.

Alas, I gave the model too much credit. It was clear all along that the development of the easterly depended upon a very complex arrangement of interconnecting lows in the mid-Atlantic to allow the necessary ridge to form. If I'd thought about it, I would have known the precise arrangement was unlikely unless modelled within T72. Lesson learned ... again!!

I would add a positive though - it looks likely that heights are going low over Europe by week 2. That may bring us closer to another northerly shot before too long.

Edited January 1, 2017 by Man With Beard

[snowwman]

37 minutes ago, KTtom said:

All looks fairly positive from my point of view, yes, the easterly looks dead in the water, however deep cold is now seeping south into Europe,  with all operationals hinting that pressure will rise again in the Atlantic a good chance of further northerly blasts increasing in intensity especially mid month would be my estimate.

Exactly, KT, and the low heights seeping deep into the Mediterranean, even by ECM:

, will make it difficult for that high to sink.

[carinthian]

2 hours ago, carinthian said:

Happy NY from Austria. Still a lot of water under the bridge till next weekend. The Mid week synoptic forecast chart from UKMO looks cold for many in Euroland and including The British Isles. The extended charts to 120t chart keep you lot under settled cold wintry conditions for most of next week. By weekend we could see a better chance of snow in week 2 for you hopefully. What I am saying , not all is lost. Much better charts than last winters full throttle zonal charts with not even a frost in sight for you guys. The general pattern remains blocked and your time will come.

 

 

C

Looks like Austria going into the freezer later in the week. Will be a shock over here with such low uppers after the mild, sunny Christmas and New Year. Still on the cold side for much of England and Wales.

C