Model thread discussion - cold spell looming

[Cheshire Freeze]

D6 GEFS mean

[feb1991blizzard]

Another significant upgrade on the GEFS 18z.

 

 

 

 

[weathercold]

11 hours ago, Snowman. said:

When you build a Scandi high they can be persistant and usually dry at the start. 

Cold air starts wrapping around the SE of the high along with low pressure and instability, that travels west underneath the high, the UK is the last stop but much of Europe begin to slowly go into the freezer.

Below is the 2018 Beast and you can see how it evolves.

 

You can see the same thing happening on the GEM. There will be a relaxation of snow but it would likely remain very cold with any snow cover persisting.

 

[GSP]

I can imagine there may be ice flows in some rivers and creeks,

[Scott Ingham]

10 minutes ago, sheikhy said:

Is there any support for this kinda scandi high from the mjo and other background signals?!!

Yes sustained mjo phase 7 to possibly 8 and a rise in AAM due to peak on the 13th. Was the basis behind my scandi height rise forecast in the yorkshire thread on monday/tuesday.

The trending is clear now. 

Very significant spell if it continues to play out this way 

[LetItSnow!]

Quite sensational chart viewing during the past 24 hours. Really does feel like we’re witnessing the beginnings of a historic cold month. 

[sheikhy]

1 minute ago, feb1991blizzard said:

Another significant upgrade on the GEFS 18z.

 

 

 

 

And also look where that polar vortex in europe is going!!its further south and west

[weathercold]

These charts really are astonishing, how many LRF’s are a bust if these charts come to fruition. We are on the cusp of an historic February. Extraordinary.

Edited February 6, 2021 by weathercold

[feb1991blizzard]

1 minute ago, sheikhy said:

And also look where that polar vortex in europe is going!!its further south and west

There's going to be some stunners on this suite, sure - not anything like a majority yet, but i wouldn't rule out a -17c on the London graph when it comes out.

[nick sussex]

The bit that interests me in this run , around T 168 hrs if you look at the upstream troughing you’ll see the shortwave on the base of that .

Its that point where more energy needs to go se towards southern France . We need that to go se and the trough to split , the other part heads n/nw that will allow the Scandi high to gain some elevation as the western flank lifts nw into that gap . That will help to change the track of the cold pool .

The deep stunning cold is heading sw and it’s a race against time to gain elevation in the high before that goes past the point of no return . 

Sounds dramatic ! And it certainly will be if those purples  make landfall in the UK !

[GSP]

Oh no, not again!

 

[Mike Poole]

I’ve not posted much today, I expected the cold to prevail, but what has happened in the model output has surprised me on two counts, first I didn’t expect it this morning!  Maybe Sunday, I said last night.  Second, the GFS seems to be at the vanguard of this new cold evolution, which isn’t what you would expect, it normally has to be dragged kicking and screaming into line with the UKMO and ECM in these situations.  

All of which gets a BOOM from me.  This looks like the proper real deal, and if you allow for a SSW to influence for two months, there’s a whole one left, should be a freezing and very interesting February indeed.  

18z is an absolute stonker of a run.  And for once I am confident it won’t downgrade in the morning....

Edited February 6, 2021 by Mike Poole

[Battleground Snow]

Control at 186

[Snowman.]

Improving GEFS mean again.

 

[North Easterly Breeze]

Darcy... looks a massive storm.

[GSP]

Plenty of convection coming in from the north sea to affect a large part of the country in hit number 3, or is it 4? Losing count!

 

Edited February 6, 2021 by GSP

[Cloud 10]

GFS not happy with two beasts and wants to outdo itself with a third!

 

[Snowman.]

Boom from me here.

 

[Mike Poole]

GFS T360:

How far away are those -20’s?

[Allseasons-Si]

Scandi high gaining traction in the medium term now but this has to have a mention...

ROUND 3?!!!

[Cloud 10]

 

[CentralSouthernSnow]

38 minutes ago, Captain Shortwave said:

The GFS successfully sheers away the base of the ridge and allows the Scandi high to become fully detached with the jet stream running underneath. 

      

850s of -14C into the south on this run.

Would the lows undercut the south of uk? 

[Johnp]

A long way out, but one of the best charts I've ever seen 

[GSP]

Oh my good gord! And look at the streamers!

Edited February 6, 2021 by GSP

[Zak M]

Christ al-mighty

Round 3 anyone?