Model Output Discussion - Into the new year

[kold weather]

So just worth noting what @bluearmy said earlier today on the 12z EPS, there are a number of GFS ensemble runs that take much longer to break down the riding to our north to allow a northerly as per the OP. Some don't ever. 

So what happens on some runs is we ingest milder air, at least at 850hpa from the ESE, though for quite a few runs its temporary.

Probably would be a fair risk of a snow event in that type of situation, though obviously the further north any area like that got the more a snow-rain risk increases for the south.

However that really is out in lala land, lets get the 120hrs into the 72hrs range, still time for this to go very wrong, regardless of how good the background set-up looks at the moment.

[Cheshire Freeze]

Control gives near blizzard conditions for parts of England and Wales at D10- very marginal though

[Allseasons-Si]

The signal is there for a Greenland high looking at the postage stamps at day ten.

the gfs also shows a split again in fl.

[Frigid]

Wow. Just wow. If this snow actually came off it would be a week to remember indeed. Let's hope we get something similar  

[kold weather]

5 minutes ago, CreweCold said:

Control gives near blizzard conditions for parts of England and Wales at D10- very marginal though

Based on the airflow, my guess is that might be a snow-rain type event, at least for the SE/EA, its very good the further west you go though.

[Snowman.]

What a mean!

[feb1991blizzard]

13 minutes ago, Allseasons-si said:

WOW!!!!

Look at that mean at day ten...

 

WOW - look at the mean at D11.5!

 

 

[Howie]

1 minute ago, Snowman. said:

What a mean!

The jet stream is beautifully far south

[MATTWOLVES 3]

15 minutes ago, Allseasons-si said:

WOW!!!!

Look at that mean at day ten...

 

Its outrageous si...the models have gone barmy...even the fi GFS snow charts want to keep piling it in...They used to say if it sounds to good to be true...it probably is!! Nahhh...not in this case.

[kold weather]

Euro4 has shifted a bit further north on its 18z for Wednesday:

Its still somewhat south of some of the other models but its a decent shift up from the 12z, which at the same point was decently into the channel.

I'd personally still like it somewhat further north, but its a good start.

[phil nw.]

35 minutes ago, nick sussex said:

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 !

Yes I am with you on that Nick. 

The ideal route for the cold is down through Scandinavia. 

Plenty of time for adjustment yet. The overall trend for continuing cold is very solid looking at current ens guidance. 

Some outstanding prospects now for a memorable cold spell. 

 

 

 

[Allseasons-Si]

6 minutes ago, Snowman. said:

What a mean!

It's blinding me on the NH view and it hasn't changed that much from the day ten one i posted^...

surely there is a potent northerly in the ens by that stage,...Edit:yes there are quite a few that bring a weather bomb from the north,...not kidding.

 

Edited December 28, 2020 by Allseasons-si

[Uncertainty]

Listening in to Eric Webb on Twitter and the it Looks like the world record for hPa is going to go in Mongolia - a station ‘Tsetsen Uul’ reporting 1093.5mb.

We could also have a record breaking low in the Pacific in the mid 920s.

No wonder the fire is about to start in the Strat.

Huge hemispheric happenings leading up to the Atlantic shake down. There’s serious forcing, and thus confidence, for a serious -NAO here...

 

Edited December 28, 2020 by Uncertainy

[Day_9]

37 minutes ago, radiohead said:

Scotland is absolutely buried by the 18Z GFS

M4 strikes again !  

[Crackerjack]

30 minutes ago, Howie said:

There are reports that the siberian high is as strong as 1093 millibars, astonishing. Surely that should put the +EAMT and resulting amplification into overdrive and also help knock out the spv

Wow. According to the Guinness book of records -

1083.8mb

The highest barometric pressure ever recorded was 1083.8mb (32 in) at Agata, Siberia, Russia (alt. 262m or 862ft) on 31 December 1968.

if correct then 1093 would be astonishing !!!

[Howie]

3 minutes ago, Uncertainy said:

Listening in to Eric Webb on Twitter and the it Looks like the world record for hPa is going to go in Mongolia - a station ‘Tsetsen Uul’ reporting 1093.5mb.

We could also have a record breaking low in the Pacific in the mid 920s.

No wonder the fire is about to start in the Strat.

Huge hemispheric happenings leading up to the Atlantic shake down. There’s serious forcing, and thus confidence, for a serious -NAO here...

 

Yes I was just thinking about this! It's all coming together nicely 

[Man With Beard]

8 minutes ago, Snowman. said:

What a mean!

That's outrageous. Surely a one-off. We'll be in monstrous cold if anything like this comes off.

[Howie]

1 minute ago, Crackerjack said:

Wow. According to the Guinness book of records -

1083.8mb

The highest barometric pressure ever recorded was 1083.8mb (32 in) at Agata, Siberia, Russia (alt. 262m or 862ft) on 31 December 1968.

if correct then 1093 would be astonishing !!!

Yes! Absolutely breath taking, some very strong forcing for amplification and ssw, probably hasn't even factored into the models yet and there already showing really good stuff

[Optimus Prime]

5 minutes ago, phil nw. said:

Yes I am with you on that Nick. 

The ideal route for the cold is down through Scandinavia. 

Plenty of time for adjustment yet. The overall trend for continuing cold is very solid looking at current ens guidance. 

Some outstanding prospects now for a memorable cold spell. 

 

 

 

That's definitely the coldest source of continental air available for the UK. But an easterly from Russia would eventually pull in very cold air also;

[Uncertainty]

2 minutes ago, Howie said:

Yes I was just thinking about this! It's all coming together nicely 

It’s no coincidence pal. The vertical heat energy spilling into the strat via Wave 1 through this event is gigantic. If it splits down the line as even the reluctant GEFS are suggesting then it could be effectively done for during the heart of winter. This surely is the foundation of the 6 week block fest on the EC46.

[Allseasons-Si]

Guys i need a lie down after viewing today's runs and I've only viewed the 12z/18z,...astonishing!

we are staring down the barrel of a potentially severe cold spell here and it has been long overdue,boy i do miss those days of 3 foot of icicles dangling off the gutters and several feet drifts not seen since march 2013

take care all,same tomorrow,...we hope

goodnight 

[phil nw.]

Just now, Optimus Prime said:

That's definitely the coldest source of continental air available for the UK. But an easterly from Russia would eventually pull in very cold air also;

Yes indeed.From Winters past usually GH brings the first shot of deep cold and from there we could see northern blocking switch across to Scandinavia after the trough has cut off hence more of an easterly. 

The best winters ie 62/3,78/9,would switch around with those blocks to the north. 

Some great model watching to come the likes which is now seen too rarely in the UK. 

[Howie]

8 minutes ago, Uncertainy said:

It’s no coincidence pal. The vertical heat energy spilling into the strat via Wave 1 through this event is gigantic. If it splits down the line as even the reluctant GEFS are suggesting then it could be effectively done for during the heart of winter. This surely is the foundation of the 6 week block fest on the EC46.

Very very impressive stuff, I wonder if the MJO could come into play and give us even more of a boost

[Ben Sainsbury]

To continue today's upgraded runs... The UKV 21z moves Wednesday's snow event further north.

[Allseasons-Si]

A final note...

the ext gefs ens show a marked tendency for a trough to drop south through Scandinavia into the UK whilst at the same time heights build up W of Greenland.

gefs mean still going strong with this at 348...