Model Output Discussion - Into the new year

[Optimus Prime]

5 minutes ago, kold weather said:

I do agree with you on the cuation side of things, we've been around the block and have seen these both succed and fail before!

With that all being said, I've got to be honest and say I've rarely seen the stratosphere and troposphere both so primed for northern blocking in the 16 years I've been here.

 

 

Except this year, much like 2010, we have cross-model agreement. We literally have a full suite of variables that favour a feezing January and promising Feb.

Just been through Birmingham which has been pasted, and the cold hasn't even had a chance to stagnate and accumulate.

Very exciting prospects.

[The Beast From The East]

18 minutes ago, chionomaniac said:

A more traditional channel low by the end of the ECM. Nudge it north and we could use the rare b word

Blizzards 

[Matt H]

16 minutes ago, West is Best said:

This may fall on deaf ears but I continue to urge caution. The easterly scenario is by no means nailed on. With these ensembles I continue to think it's 60:40 high pressure will settle (topple) back over the UK after the northerly:

 

I have to admit I’m struggling with this one. If there was a 60% chance of a UK high following the ridge toppling then surely there would be more signs of this playing out in the ensemble means across the main models (indeed like we have seen in the past). Of course things could change but you seem to be fairly alone amongst the members on here with more experience. I’m very much still learning so would genuinely appreciate a response. Thanks.

[Methuselah]

8 minutes ago, Mike Poole said:

Someone mentioned reverse zonal flow earlier (I won’t use the non-word ), starting to see it now at the end of the ECM run.  ECM T240:

Where’s the cold air going T216 to T240?

Anti-zonalness is coming... It just needs to carry on long enough to bring us the famed 1947 redux? Damn it, there must be a word for it somewhere!

[blizzard81]

If we are to see anything 'significant' in the first half of January, we need to see these dip at days 14 to 15 when they update later. We need to see the mean drop below the zero line. 

[Kentspur]

21 minutes ago, Harsh Climate said:

Both Icon and Aprege are much further south than ECM too. Huge caution advised this early on.

The more  Southern coastal members will no doubt prefer the Arpege outcome of course, still with a very small amount around London and the Thames region on that too

[Tim Bland]

12 minutes ago, Paul said:

I wouldn't get that far ahead yet, the UKV (UKMO's own model) not showing anything quite so dramatic at the moment. 

The Met are obviously taking note of the ECM rather than UKV though if they have issued a warning right up to midlands?

[Mike Poole]

1 minute ago, Frosty Winter said:

I have to admit I’m struggling with this one. If there was a 60% chance of a UK high following the ridge toppling then surely there would be more signs of this playing out in the ensemble means across the main models (indeed like we have seen in the past). Of course things could change but you seem to be fairly alone amongst the members on here with more experience. I’m very much still learning so would genuinely appreciate a response. Thanks.

Yes, those ‘brain’ plots really illustrate it well, there is no vortex, none at all, in our half of the northern hemisphere.  So I can’t see where any Atlantic weather could come from, what would be the driver for it?  A high could settle over the UK for a while I suppose, a bit like it does in summer, but it would probably only cool things down...

[Sam200498]

I haven’t seen that good range of charts for so long it’s going to be an exciting few days 

[bobbydog]

28 minutes ago, West is Best said:

This may fall on deaf ears but I continue to urge caution. The easterly scenario is by no means nailed on. With these ensembles I continue to think it's 60:40 high pressure will settle (topple) back over the UK after the northerly:

 

 

[MATTWOLVES 3]

Fab end to ECM,how often do we see this kind of set up moving into January...perhaps 2010 the last time,but that did tend to fizzle out come the end of December...its what's to follow that is really intriguing me now..latest tweet from Marco Petagna claiming that there is now multi model agreement on a major split of the vortex...So we could see further updates from Exeter becoming more and more encouraging..fingers crossed folks,but this could be looking exceptional.

[Anthony Burden]

ECM holding firm on northern blocking no signs of Arctic lows heading south.

Suggestion of low pressure perhaps moving up from the south in the latter end.

Staying cold to very cold through out.

[Methuselah]

Well, the GEFS 12Zs still show the deep cold moving in the right direction:

    

    

The mean SLP over Greenland ain't bad, either!

[pureasthedriven]

1 minute ago, Tim Bland said:

The Met are obviously taking note of the ECM rather than UKV though if they have issued a warning right up to midlands?

‘Small chance of disruption’. I dearly hope ECM is correct. But these days government agencies issue warnings for for the most inconsequential of possibilities. That yellow warning today for my area (never happened) was for 1-2cms! 

[Met4Cast]

5 minutes ago, Tim Bland said:

The Met are obviously taking note of the ECM rather than UKV though if they have issued a warning right up to midlands?

Wrong thread but most likely a blend of EC/UKV & MOGREPS. The more northerly solutions are still a possibility (albeit a diminishing one) so may as well cover that with the warning & then refine closer to the time. It's a shame Ian F doesn't post here anymore, his comments on what MOGREPS was showing was very helpful at times like this.

The GEFS postage stamps pretty much every route possible.

Edited December 28, 2020 by Met4Cast

[kold weather]

By the way the ECM 12z control does something very similar to the OP where it swings the front back westwards again.

Several models have recently been doing this set-up (ICON has toyed with it several times) so worth keeping an eye on.

Very strong agreement of snowfall across the southern half of the UK btw from the ECM ensembles, though some still are a little further north than the OP. Not too many further south.

[Mike Poole]

8 minutes ago, MATTWOLVES said:

Fab end to ECM,how often do we see this kind of set up moving into January...perhaps 2010 the last time,but that did tend to fizzle out come the end of December...its what's to follow that is really intriguing me now..latest tweet from Marco Petagna claiming that there is now multi model agreement on a major split of the vortex...So we could see further updates from Exeter becoming more and more encouraging..fingers crossed folks,but this could be looking exceptional.

Yes, I think there is multi-model agreement re the split, the ECM and GFS // have been consistent for a while, the JMA also, GFS has been reluctant but if we get a split like this (JMA as example):

I would be pretty happy to call a deepening of the cold outlook for the UK, which may be getting pretty deep anyway, stick by my 5th Jan punt for SSW, btw!

 

Edited December 28, 2020 by Mike Poole

[bluearmy]

21 minutes ago, Optimus Prime said:

Except this year, much like 2010, we have cross-model agreement. We literally have a full suite of variables that favour a feezing January and promising Feb.

Just been through Birmingham which has been pasted, and the cold hasn't even had a chance to stagnate and accumulate.

Very exciting prospects.

 Steady on 

just a note on the 12z eps and the threat of those less cold uppers heading north by day 10 shown on the run to run change 

[bluearmy]

7 minutes ago, Met4Cast said:

Wrong thread but most likely a blend of EC/UKV & MOGREPS. The more northerly solutions are still a possibility (albeit a diminishing one) so may as well cover that with the warning & then refine closer to the time. It's a shame Ian F doesn't post here anymore, his comments on what MOGREPS was showing was very helpful at times like this.

The GEFS postage stamps pretty much every route possible.

EC postage stamps now freely available ......

[Beanz]

12 minutes ago, Met4Cast said:

Wrong thread but most likely a blend of EC/UKV & MOGREPS. The more northerly solutions are still a possibility (albeit a diminishing one) so may as well cover that with the warning & then refine closer to the time. It's a shame Ian F doesn't post here anymore, his comments on what MOGREPS was showing was very helpful at times like this.

The GEFS postage stamps pretty much every route possible.

That’s very different to the ECM...

 

[Jason M]

1 minute ago, bluearmy said:

 Steady on 

just a note on the 12z eps and the threat of those less cold uppers heading north by day 10 shown on the run to run change 

This solution is not without support in the GEFS either. Nothing like a Spanish plume in early Jan. My guess for the 'B' word was Barbeque. The block could still go  shaped.

Its certainly not a bad outlook (in fact its a good one!) but I always get worried when people start talking like its a done deal. As we know, sometimes the train doesn't arrive! If it does though, it could just be very good indeed.

 

[SMU]

This is the EPS mean.PPN 72 accum over that 24 hour period.

[kold weather]

4 minutes ago, bluearmy said:

 Steady on 

just a note on the 12z eps and the threat of those less cold uppers heading north by day 10 shown on the run to run change 

Worth noting that alot of those runs that do get warmer are doing so because they are developing a mean ESE airflow as a LP rolls through Europe = classic surface cold type set-up with warmer air riding above. 

Of course, if the wind were to then shift back eastwards we may find we can only tap into a marginal easterly flow for a short while if the cold pool is shoved too far north from that ESE flow.

 

[Penicuikblizzard]

2 hours ago, Steve Murr said:

Upgrade to sub boom status for PTB 29...

Do these ensemble charts ever come to fruition as it always seem be these charts that are belters?

[Portsmouth Sun]

1 minute ago, Penicuikblizzard said:

Do these ensemble charts ever come to fruition as it always seem be these charts that are belters?

Generally not, hence why we are not currently buried in snow.  Nothing like a D10 to get people in hysterics.