Model Output Discussion - the cold has arrived

[northwestsnow]

Under normal circumstances you'd like to think on the 18th of Dec a 12z run won't be far off wrong for the 24th / 25th of December but clearly this is knife edge stuff..

Even if UKMO and GFS look similar to ICON I still won't relax until the Grinch ( EC) comes on board..

ICON 850S for the 25th look  

Now COME ON ecm !!!

[Snowyowl9]

So we are looking at christmas day at the earliest for the next cold snap and possibly a white christmas you only need a few flakes..

CFS..and GEM gives you a little hope..

[Tim Bland]

Looking increasingly likely that somewhere is going to get a white Christmas this year! 

[frosty ground]

4 minutes ago, northwestsnow said:

Under normal circumstances you'd like to think on the 18th of Dec a 12z run won't be far off wrong for the 24th / 25th of December but clearly this is knife edge stuff..

Even if UKMO and GFS look similar to ICON I still won't relax until the Grinch ( EC) comes on board.

 

think we could be waiting until Wednesday before the track of any low will be decided 

[Mark wheeler]

Good start to the 12z lets hope its a small snow ball at the top of the hill and once it gets to the end its a big Boulder. A bit further south please

[geordiekev]

One of the big bookmakers suspended betting on a White Christmas at midday. Clearly they mustn't have been reading this thread & instead possibly checking the latest models. Good luck if you got anything better than evens for oop North

[Mucka]

So GFS just 72h in but little changes here can matter later.

Polar high is slightly better placed as with the 06z so hopefully that can help the trough dig S in the mid term, especially if we manage a link up with our waning Greenland heights, albeit a temporarily

Edited December 18, 2022 by Mucka

[Mucka]

5 minutes ago, geordiekev said:

One of the big bookmakers suspended betting on a White Christmas at midday. Clearly they mustn't have been reading this thread & instead possibly checking the latest models. Good luck if you got anything better than evens for oop North

It is always based on how much money/how fast they are taking so there must have been a sudden influx that made them nervous.

Hope Santa hasn't risked all that gift money!

[Mucka]

UKMO 96h, improved Atlantic?

[Don]

9 hours ago, CreweCold said:

My thoughts too.

If it’s a temporary weak fart northerly you’re after then yes, perhaps there may be a chance around Christmas Day…but even then the chances are any precipitation has long pulled away or fizzled out.

From a broader perspective the writing is on the wall for the AO to go neutral then positive just after Christmas. All that will do is further lock in the Euro HP and condemn the UK to being exposed to zonal westerlies.

I suspect the stratosphere will eventually weaken via a SSW, but that may be later January. 

I hope I haven't missed the opportunity for snow this winter, given I hardly saw any during this outgoing cold spell?!  That said, I find it encouraging you expect a SSW at some point!

Edited December 18, 2022 by Don

[Skullzrulerz]

2 minutes ago, Mucka said:

UKMO 96h, improved Atlantic?

Santa may come bearing gifts

[Mucka]

1 minute ago, Skullzrulerz said:

Santa may come bearing gifts

He may, but he may also be late to the party! 

[Mike Poole]

Early doors on the GFS looking promising compared to the 6z, with the low further east and weaker already, and the earlier two runs were upgrades on yesterday, so the trend continues.  T126 v 6z T132:

Edited December 18, 2022 by Mike Poole

[Mucka]

Well here we go, cold and some snow sinking S Christmas eve.

1 minute ago, Mike Poole said:

Early doors on the GFS looking promising compared to the 6z, with the low further east already, and the earlier two runs were upgrades on yesterday, so the trend continues.  T126 v 6z T132:

Aided by lower Euro heights, great trend to have.

[Snowmadsam]

I’m liking the 12z much more!! If we can get clearance quickly, rain to snow

BINGO!

Edited December 18, 2022 by Snowmadsam

[Methuselah]

So, here we are at T+120 (GFS 12Z) and it's anyone's guess as to what's going to happen:

    

Back in the days of yore, I'd have plumped for a cold evolution; these days, I'm not so sure!

[Mucka]

UKMO not on the same page, keeping those Euro heights although the Atlantic sector (ridge) is slightly improved, but we need the first half of the puzzle.

Edited December 18, 2022 by Mucka

[Johnp]

3 minutes ago, Mucka said:

Well here we go, cold and some snow sinking S Christmas eve.

Aided by lower Euro heights, great trend to have.

Not a particularly great UKMO run though.

[TSNWK]

Sh close to be a decent run for us all. If in north of Leeds Manchester I’ll be down the bookies with tenner for a white Christmas. Quiet a big shift east with the low on this one.

 

Edited December 18, 2022 by TSNWK

[Purga]

12z GFS looking better with the Atlantic low moving east quicker and hopefully phasing with the Scaninavian Low

[Weathizard]

1 minute ago, Ed Stone said:

So, here we are at T+120 (GFS 12Z) and it's anyone's guess as to what's going to happen:

    

Back in the days of yore, I'd have plumped for a cold evolution; these days, I'm not so sure!

People must be looking at something else to me on this, how will cold air flood south with heights like that over Europe?

 

Answers on a postcard please, I guess it depends if you want to see falling flakes or proper cold.

[Mucka]

This would be a great Christmas morning chart, bank it.

[tight isobar]

Another upgrade on the 12z the cold north to south escalating...

[Johnp]

3 minutes ago, Weathizard said:

People must be looking at something else to me on this, how will cold air flood south with heights like that over Europe?

 

Answers on a postcard please, I guess it depends if you want to see falling flakes or proper cold.

But the subsequent charts literally do show the cold coming south over us?

[Tim Bland]

Chance of a technical white Christmas almost anywhere on this run.  I got 3-1 on Glasgow last week, happy with that! Just need 1 flake in 24hrs