Model Output Discussion - Into the new year

[iceman1991]

8 minutes ago, Snowman. said:

3 Pockets of cold, one over the southern england, one north of Scotland and a new one east of greenland.

Best OP we have seen so far this winter period.

That snow chart Accurate only 5 cm for south roughly that can’t be right with all this snow maybe coming ?

[Met4Cast]

18z GFS has found the cold.. finger of sub -20c 850hPa over Iceland..

[SLEETY]

Rare to get that depth of cold into Iceland heading South,be biblical up their with the contrast between upper air temps and the warm sea,can we hit the jackpot and get that depth of cold here too.

[Matt H]

28 minutes ago, Zak M said:

Don't show this run to The Express!!

      

“Arctic weather bomb to cripple the UK under 6 feet of snow in the New Year!” [Insert image of heavy snow from google images]

Edited December 28, 2020 by Frosty Winter

[Ice Day]

4 minutes ago, Stu_London said:

Parallel looks a bit ropey 

Well when this is the worst of the bunch, life really is looking rather peachy for those of a cold persuasion.  The GFSP is now at 240, a different solution but the end result appears to be the same!?!?!?  Pointless looking at detail at this range, but the point stands.

[Howie]

3 minutes ago, Allseasons-si said:

Je...sus

WOW!

[Catacol]

2 hours ago, Griff said:

No doubt this will get lost under a deluge of strat and -nao based excitement, but I can't for the life of me remember a week ahead forecast IMBY across multiple weather services with daytime temperatures of 1°c showing precipitation type as rain?!?

Presumably 2m surface temperatures, but dew points must be higher than 0. Not sure what's happening, are we under inversions?

We are still cooling down. 48 hours ago it was mild, wet and lots of latent warmth knocking around. It will take a bit of time given the slow burning nature of the cold’s arrival. Sharp frost here last night - a few more of those and more time for this stagnant trough to keep cooling and we’ll be fine. And then the cavalry arrives.....

[kold weather]

1 minute ago, Stu_London said:

Wonder what the January 2021 CET would look like if the models and the background signals for the second half of the month come close to verifying. 

Got to be sub 2C, surely?

Probably be close to a sub zero first half IF the 18z came off.

Of course the 18z  is probably somewhat on the extreme end of the options. The parallel probably is more reasonable in terms of timings.

As @Catacolhas just said, going to take something pretty major to shift out of the cold spell now. IMO the only real risk is whether or not this shifts too far west too quickly. So in a funny sort of way, the HP taking a little longer IMO reduces this risk a little. Given the background pattern we'd be very unlucky to not get some decent northern blocking. Whether or not the HP will hang around a few extra days eventually is not going to make much difference, and will keep us cold regardless.

 

[Cheshire Freeze]

The UK becomes an extension of the Arctic on this 18z run...

[Uncertainty]

6 minutes ago, Zak M said:

Don't show this run to The Express!!

      

Just goes to show Zac if you baselessly predict 12 inches of snow every week for 7 months of the year you’re bound to be right sometime!

[Stu_London]

Just now, Catacol said:

We are still cooling down. 48 hours ago it was mild, wet and lots of latent warmth knocking around. It will take a bit of time given the slow burning nature of the cold’s arrival. Sharp frost here last night - a few more of those and more time for this stagnant trough to keep cooling and we’ll be fine. And then the cavalry arrives.....

Have a bit of a battle with higher relative humidity before we reach the thermal minimum and higher dewpoints as a result - would be better in early February onwards but then the big orange thing in the sky increasingly become the enemy.

[BLAST FROM THE PAST]

29 minutes ago, feb1991blizzard said:

This run in my eyes is the best 192 chart i have seen this winter, you could get a pasting in a few frames time from this, coldish uppers coming, low heights and kinks in the surface pressure isobars!

It is mate as I posted how it could retrograde.....just commenting on potential hiccup territory and being fair to Richard as we have to cross that bridge which is a reasonable stand point

 

BFTP

[andymusic]

1 minute ago, CreweCold said:

The UK becomes an extension of the Arctic on this 18z run...

18z - the polar bears start moving their stuff into the uk lol

[dhillcrest]

I've been following this thread since 2010 when I got sucked into the euphoria of that year's cold snap - I love a bit of snow, me. I wanted to see what the experts said and fed off the enthusiasm in here. It was glorious. Now, I know nothing, NOTHING about the charts (much to my disgust) but every year I come back in December to see what the prospects are.....

Is it my imagination, or have I seen charts and enthusiasm simillar to what were seeing now a good couple of times in the last ten tears only to see them collapse to mediocrity within the 120 hour time frame - sometimes even less.

Is there something different about these charts this year or is there still a chance everything will evaporate into sludge at short notice? I ask because I ramp all this up to my wife all the time and then when it doesn't happen she blames me personally and calls me an idiot.

 

Mods - this is slightly connected to models so bear with me 

 

Edited December 28, 2020 by dhillcrest

[Cheshire Freeze]

8 minutes ago, Uncertainy said:

Some people are running on to the pitch they think it’s all over...

@CreweColdcould teach those seasonal models a thing or two! He called this winter in August! The signs have been loud and clear in the modelling since late November, you can thank the Urals high for that. 

 

I made a fairly bold assumption that the La Nina would be nowhere as near as intense or long lasting as the models were suggesting...I put that together with the low solar summer pattern we witnessed, looked at a few other drivers (QBO etc) and made a call.

My confidence rose at the back end of October and through November as the classic SSW precursor patterns took hold.

[Stu_London]

4 minutes ago, dhillcrest said:

I've been following this thread since 2010 when I got sucked into the euphoria of that year's cold snap - I love a bit of snow, me. I wanted to see what the experts said and fed off the enthusiasm in here. It was glorious. Now, I know nothing, NOTHING about the charts (much to my disgust) but every year I come back in December to see what the prospects are.....

Is it my imagination, or have I seen charts and enthusiasm simillar to what were seeing now a good couple of times in the last ten tears only to see them collapse to mediocrity within the 120 hour time frame - sometimes even less.

Is there something different about these charts this year or is there still a chance everything will evaporate into sludge at short notice? I ask because I ramp all this up to my wife all the time and then when it doesn't happen she blames me personally and calls me a apple.

 

Mods - this is slightly connected to models so bear with me 

 

There are a number of similarities to December 2010 - not as cold...yet

The biggest similarity is that the Polar Vortex has been under extreme pressure since autumn.

The biggest difference is that 2010 didnt have an SSW and the vortex got its proverbial together eventually which led to a relatively mild Jan and Feb 2011. We have the SSW looking likely this year, which gets a ticket in the raffle at least.

 

 

Edited December 28, 2020 by Stu_London

[Mair Snaw]

Everybody its time to panic buy bread and milk while you can still get out your front doors... stunning model runs again today.. just gets better and better. Im off to watch "the day after tomorrow " to prepare for January 2021...Bring me my snaw

[nick sussex]

Nothing special,  probably a mild outlier ! 

Joking aside a good run but , and there’s always a but ! The pattern needs to be further se . You want the deep cold coming south further east.

Very cold upper air heading south over warmer waters is likely to lead to lots of shortwave activity and the block is too far west .

Not being a grinch but there’s room for improvement . Let’s aim high !

[IanT]

9 minutes ago, Frosty Winter said:

“Arctic weather bomb to cripple the UK under 6 foot of snow by the New Year!” [Insert image of heavy snow from google images]

Those charts are for the 9th January, not “by the New Year”...

[kold weather]

Looking through the 18z ensembles upto 168hrs and its fair to say that the op run is certainly one of the more aggressive runs with how it evolves the pattern.

Some do keep the HP much close to the UK for longer, however nearly all have a set-up that will mean the HP will retrograde towards the NW at some point.

My guess is that there will be some runs that take longer to get there, but I think most will, and pretty much all remain cold, or very cold.

Also one word of caution, still ALOT of different solutions out there, they all go cold but I'd like to find some consistency first. 

Edited December 28, 2020 by kold weather

[Allseasons-Si]

9 minutes ago, andymusic said:

18z - the polar bears start moving their stuff into the uk lol

Yep,...spotted them

Short gefs ens showing a tight clustering of -8 towards the 4th Jan.

 

Edited December 28, 2020 by Allseasons-si

[Man With Beard]

18 minutes ago, Allseasons-si said:

This run has all the hallmarks of...

Would suggesting 1962 be pushing it for a comparison? (Answer=Yes )

[Battleground Snow]

Another rock solid mean at 180, just lovely.

 

[Met4Cast]

We are on the brink.. we are standing right on the brink of something potentially noteworthy and very, very special. 

All the ingredients are coming together in a way they haven't since 2009/2010 & we are staring down the barrel of a potentially exceptional January. We're so close.. but we're not there yet.

[Jason H]

5 minutes ago, Allseasons-si said:

Short gefs ens showing -8 towards the 4th Jan.

 

Yeah. That's pretty conclusive. Despite all the different GFS operationals, it's all heading one way. Firming up on the cold.

Edited December 28, 2020 by Jason H