[Model discussion highlights]

2 minutes ago, Bricriu said:

Yes.  In future  runs that low to the south west could be a spoiler for instance.  I am  going to try and contain my excitement for now .

It's like children in a candy shop who've been told by the owner they can help themselves to as many sweets as they want in here.

Sugar rush over day 10+ charts showing deep cold and snow.

Maybe after watching and discussing the models for 20+ years I've got a bit weary of the excitement of cold and snowy nirvana past day 7.

I'll join in when it's still showing below 7 days.

 

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4994977

[Model Output Discussion - Into 2024]

5 minutes ago, TSNWK said:

Hello, is there something nagging you on what is currently being progged? That leads you to keep the champagne on ice  

Not for now, we have a lot of consistency from models and their ensemble guidance which is a plus, but been burnt too many times at that range!

 

[Model Output Discussion - Into 2024]

2 minutes ago, Bricriu said:

Yes.  In future  runs that low to the south west could be a spoiler for instance.  I am  going to try and contain my excitement for now .

It's like children in a candy shop who've been told by the owner they can help themselves to as many sweets as they want in here.

Sugar rush over day 10+ charts showing deep cold and snow.

Maybe after watching and discussing the models for 20+ years I've got a bit weary of the excitement of cold and snowy nirvana past day 7.

I'll join in when it's still showing below 7 days.

 

[Model Output Discussion - Into 2024]

I'm not getting too excited yet, we are still talking day 10 and the -10C line is arriving across northern Scotland on 12z GFS. A lot can change before then, though granted the models are being consistent!

[Model Output Discussion - Into 2024]

Well, Greece and Turkey get in on the deep cold before we do on 12z GFS 

[Model discussion highlights]

Oh dear, the annual comparisons to 62/63 being uttered.

Got my tin hat ready in case it goes Pete Tong 

But not often you see such a strong +height anomaly over Greenland at T+300, as below on 12z EPS

Same time Europe in the freezer looking at T2m mean anomaly

NOAA CPC 8-14 day heights look similar 

 

 

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4994151

[Model Output Discussion - Into 2024]

Oh dear, the annual comparisons to 62/63 being uttered.

Got my tin hat ready in case it goes Pete Tong 

But not often you see such a strong +height anomaly over Greenland at T+300, as below on 12z EPS

Same time Europe in the freezer looking at T2m mean anomaly

NOAA CPC 8-14 day heights look similar 

 

 

[Model Output Discussion - Into 2024]

Going against my wisdom to look too far ahead, but @Mike Poole analogy of a nice starter next week, but the mains to follow could be even better ...

[Model Output Discussion - Into 2024]

1 minute ago, Battleground Snow said:

That will come, by 120.

@Jason M there have been examples of decent falls even under higher pressure,.

Somebody posted the examples the other day of this, but I forgot who it was

It often snows with high pressure at the surface, so long as there is not a strong ridge aloft with subsidence, just need cold air advection over relatively warm sea (eg North Sea) to produce thick enough cloud for flurries / showers. SE / E England best chance for some flurries / showers with deeper cold air advection and lower heights closer to the upper low over the near continent.

[Model Output Discussion - Into 2024]

8 minutes ago, Mike Poole said:

Yes, I’m not sure what the cheering is about, we don’t want to lose the main course for the sake of a better starter.

What if there is only one course on offer, any subsequent courses may not leave the kitchen, too far out to know for sure 

Cheeky little streamer for our SE contingent on Monday on ICON.

[Model Output Discussion - Into 2024]

7 minutes ago, Met4Cast said:

Given this mornings 06z GFS and now the 12z ICON i think the trend towards something wintry in the E/SE day 4 into 5 is beginning to grow. 

Yes, still far enough out for some 'upgrades' to cold into early next week. Can't imagine the models have an accurate handle on the position of the developing high - given the upper trough still has to dig into Europe later this week then disrupt into a cutoff upper and surface low over the Med over the weekend for the high to build.

12z ICON could be a more extreme solution for cold air advection, but can't rule out this depth of cold

[UK Storm and Severe Convective Forecast]

UK Severe Convective & Storm Forecast - Issued 2023-12-30 09:45:57

Valid: 30/12/2023 0900 - 31/12/2023 0600
SEVERE CONVECTIVE WATCH - SAT 30TH DEC 2023

Click here for the full forecast

[Model Output Discussion - Into Winter]

Good to see a deep Genoa Low on the GFS, always a good omen for coldies, though it's not in the reliable yet.

[Model Output Discussion - Into Winter]

Uh oh, the 06z GFS op has gone rogue from it previous runs and ensembles - maybe playing catch-up with the ECM colder trend?

Still a waiting game to see if this blocking signal to the NW has mileage, but seems a good signal from EPS for now.

[Model Output Discussion - Into Winter]

00z EPS have trended a little colder than the 12z run yesterday. GEFS seem much less enthusiastic in any colder trend. Lets hope EC is leading us the right way!

12z yesterday                                           00z today

[Model Output Discussion - Into Winter]

00z EPS H500 and T850 mean anomaly at day 10 will please coldies

[Model Output Discussion - Into Winter]

Not really until into the 2nd week of Jan does the 12z EPS mean get all the UK cold / below average temps. But it has been looking like that the last few days anyway, jet doesn't get far enough south to bring the cold to all before then.

Patience as always, fingers crossed it's not another false dawn like the late Dec promise that failed in the end. This time the trop drivers are lining up more favourably for the right pattern change, even without a SSW.

[Model Output Discussion - Into Winter]

11 minutes ago, Lukesluckybunch said:

Watching those Iberian heights at day 10 ..could be the spoiler like on the ECM

I'm not the only one concerned that the jet stream struggles to get far enough south in recent winters, because of the sub-trop high pressure belt expanded northwards, even when high lat blocking is signalled. It hampers cold air getting further south than Scotland. Lets hope we get a greater push south of high latitude blocking in January, as at the mo it's not coming into reliable.timeframes. Always beyond 7-10 days. 

[Model Output Discussion - Into Winter]

Trend GIF for last 4 EC high res runs for 12z 1st Jan show the shift south overnight of the jet stream & consequently track of lows towards NW Europe for 1st few days of New Year. That wedge of +ve heights suddenly appears to the SE of Greenland on 00z run:

[Model Output Discussion - Into Winter]

Quite a big change from the models for the 1st few days of the New Year, was looking rather mild with long-draw SWly winds, but the models this morning have pulled the jet stream further south, with that low moving up from the Azores underneath that wedge of +heights over the far North Atlantic. Something stirring ...

[Model Output Discussion - Into Winter]

12z UKMO offers up a 'wedge of hope' this time next week, with wedge of high pressure building to the NE on back of low moving SE into near continent pulling in cold air briefly

Probably won't be continued though!

[Increasing possibility of a Sudden Stratospheric Warming in the New Year which may bring colder weather]

Blog looking at the increasing probability from weather models for a Sudden Stratospheric Warming in early January, which could bring colder and wintry weather, especially if there is a split in the polar vortex following the SSW.

View the full blog here

[Rare sightings of nacreous clouds as far south as Kent today]

The stratospheric polar vortex is currently displaced towards northern Europe and has brought very cold temperatures in the stratosphere above the UK and Ireland, leading to nacreous clouds which have been sighted as far south as Kent.

View the full blog here

[SE, London and East Anglia Weather Discussion - Dec 2023 on]

Got some nacreous cloud here in Caterham-on-the-hill in Surrey Not seen them this far south before.

[Model discussion highlights]

Yes, I've recently become unconvinced by the whole solar min = cold winters / solar max = mild winter idea. So much so, I didn't include it in my current winter forecast for Netweather.

Jan/Feb 1979 was very cold and snowy, yet there was a solar cycle max that year, albeit in December. Winter 1968-69 had cold Dec and Feb (Feb had CET of 1C) despite solar max in Nov 1968. Then we had solar min on Dec 2019 - look how that winter turned out. Winters of 1974-75 and 1975-76 were mild, despite a solar min in March 1976.

There are mentions out there over the years that just after a solar min is when colder winters are more likely, like 2009-10 / 2010-11. But it doesn't stack up for other solar cycles. 

Back to the models, at least it doesn't look too mild on Xmas Day on 12z EC, especially up north in the strong NWly:

 

Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4980323