Model Output Discussion - the cold has arrived

[The PIT]

LOL back to deep winter on this run. So Santa may need to get his four wheeled drive out rather than his Deer.  I guess the deciding factor is whether the killer of cold spells past,  the secondary feature develops or not. All eyes down for the ECM.

[supernova]

7 minutes ago, Snowmadsam said:

 

No but in all seriousness, that would be bitter! 

60/40 on the ECM potentially coming out with a colder option this evening, its a hunch. No evidence backing it. I could be very wrong.

-2 in London and -13.2 850's apparently. We can but hope! Actually that isn't even the best bit. Check out the precipitation spike although perhaps rain rather than snow (in London - maybe not further north) should ever it come to pass.

Edited December 14, 2022 by supernova

[1947s coming]

1 hour ago, Allseasons-si said:

This stunning...

Not far from a link up from the Greenland high and artic and cold air looks further south , and flattening the high to the south . I still don’t think this is sorted by a long way,can we start to see the lows slide I really don’t think the models can handle cold blocks to well and very possibly underestimating the cold in place . It certainly makes for interesting viewing, by Friday we might be a little more wiser 

Edited December 14, 2022 by 1947s coming

[Methuselah]

I find I'm liking the latest GFS operational run; not, because I think it's got many details correct, but because it reminds me of the snowy, yet not overly cold winter of 1969-'70 -- cold and sometimes snowy weather from the N or NW (replete with a few sliders) alternating with mild air from the S or SW... But, before I get too carried away, it might all be utter piffle?

    

    

    

And BTW, 1969 was not a white Christmas but New Year 1970 (at least in Tunbridge Wells) was.

 

Edited December 14, 2022 by Ed Stone
must be snow-blind!

[Eagle Eye]

43 minutes ago, mulzy said:

Word of warning: Little support for the GFS from the GEM and UKMO det runs.

I think this thread may not be for you

On a more serious note, we need to remain cautious whatever the output at this range because things can switch quickly on the models.

Edited December 14, 2022 by Eagle Eye

[Allseasons-Si]

The mean is flatlining compared to this morning,...huge upgrade in terms of prolonging a colder outlook.

[That ECM]

42 minutes ago, bluearmy said:

So much uncertainty and a lot of this must be down to that Arctic high which is monstrous 

very little continuity on how it evolves and the polar profile with it 

Notoriously difficult to model I believe?

[bluearmy]

6 minutes ago, Noob said:

So much for the deep freeze 5 degress today and not a frost for 2 days....seems the weather will do the opposite to what any model says 

You’re on the coast!  Since Saturday at 5pm we’ve managed half an hour above zero at 0.1 c   

The gefs mean is pushing those euro heights se a bit.  Little by little ! 

Edited December 14, 2022 by bluearmy

[sukayuonsensnow]

GFS 12 looks like a repeat of what we just got. (Which is better than the usual mild and wet weather I guess)

Also I don't take snowfall amounts too literally when a northerly occurs on GFS especially if it's 5 days or more after. Usually near the time they got watered down.

Parts of Scotland could have a very notable cold/snowy spell with the tiniest mild blip on Monday.

[frosty ground]

the great Xmas eve blizzard from the control run 

[sheikhy]

8 minutes ago, Allseasons-si said:

The mean is flatlining compared to this morning,...huge upgrade in terms of prolonging a colder outlook.

Also a bunch where they bring in the cold air 2 days earlier!so instead of 22nd it comes in on the 20th!!one to keep an eye on!!

[danm]

55 minutes ago, Tim Bland said:

Imagine a snowy slider / channel low on Christmas Day …not far off is it ?!

A Christmas Day blizzard? Yes please. 

[chris55]

1 hour ago, northwestsnow said:

GFS 12 Z is in festive spirit

0c isotherm right down to the Pyrenees! 
 

 

[chris55]

1 hour ago, ICE COLD said:

Better . -12s into Scotland

Sub 520 thicknesses for England and wales with 850s at -6 to -8!

Scotland even colder! -12 at 510 :0
 

 

[Methuselah]

7 minutes ago, danm said:

A Christmas Day blizzard? Yes please. 

I'm still waiting for last year's, Dan!

[I remember Atlantic 252]

Another good looking 12Z GFS, has to be snowier than precip charts make out, still FI, but best chance for my area to see first decent snow

[Frigid]

21 minutes ago, Allseasons-si said:

The mean is flatlining compared to this morning,...huge upgrade in terms of prolonging a colder outlook.

Was just gonna post this, great developments indeed. many ens going for cold after Monday. 

As for temperatures, Christmas day looks.. christmassy 

  

uppers look great after the initial mild push, they really didn't have a chance in this run 

 

Edited December 14, 2022 by Frigid

[ITSY]

16 minutes ago, Allseasons-si said:

The mean is flatlining compared to this morning,...huge upgrade in terms of prolonging a colder outlook.

An almost unbelievable twist again. GEFS back the op here, up to the medium term anyway. It’s on the lower end of the pack but it’s not an outlier - the clue is in the name, it would have to be outside the rest of the pack to be an outlier and until the mid point anyway, it’s certainly not. Very encouraging for a prolongation of seasonal weather after this weekend. Let’s see what ECM throws up. Even the hemispheric profile on the UKMO is excellent, even if it’s slightly off for our locale. 

[Anthony Burden]

Evening all,the charts are struggling big time with the evolution,not advisable at present to take much notice of anything over 120 hrs,Met Office still stating the uncertainty perhaps Matt Hugo or Nick can give the reason for such uncertainty in the forecast.

[Bristawl Si]

1 minute ago, Anthony Burden said:

Evening all,the charts are struggling big time with the evolution,not advisable at present to take much notice of anything over 120 hrs,Met Office still stating the uncertainty perhaps Matt Hugo or Nick can give the reason for such uncertainty in the forecast.

MattH covered a few 'angles' in a post a couple of pages back

[Cheshire Freeze]

Just now, Anthony Burden said:

Evening all,the charts are struggling big time with the evolution,not advisable at present to take much notice of anything over 120 hrs,Met Office still stating the uncertainty perhaps Matt Hugo or Nick can give the reason for such uncertainty in the forecast.

When there’s an Arctic HP in the mix, uncertainty reigns supreme.

Add to that the usual issues with things like jet stream velocity, angle, and general energy distribution in the N Atlantic, you get this uncertainty.

[Purga]

12z Op is certainly not without support!

GEM is also very interesting for Xmas Eve.

Enjoy the ride!

Edited December 14, 2022 by Purga

[That ECM]

1 minute ago, Anthony Burden said:

Evening all,the charts are struggling big time with the evolution,not advisable at present to take much notice of anything over 120 hrs,Met Office still stating the uncertainty perhaps Matt Hugo or Nick can give the reason for such uncertainty in the forecast.

Hi, the uncertainty is that you have nhp as is. You then have gefs that show this. Where the purple and green land gives our area a lot of different outcomes. Over the last couple of days we’ve had examples of both good and bad for cold. 

[Mike Poole]

ECM T120 v 0z T132

Notable differences greater push east into Greenland, also low to our immediate west is notably weaker, both good signs in my opinion:

 

[Skullzrulerz]

1 hour ago, Stuie W said:

Very true mate. I forget that not everybody sees what I post and should have said it was a correction South from just Scotland previously.

Easily done mate! We all get a bit carried sometimes I wouldn't worry about it lol