Model output discussion - into the start of Winter

[northwestsnow]

18z gets progressively colder as Euro low works its magic ...

[Zak M]

The 18z GFS looks like the best run this evening, and is showing sub-7 daytime temps for days 8 and 9. I reckon that there could be some snow down to lower levels in northern areas, while southern hilly areas could also see a chance of snow in this run, and potentially sleet too, to lower levels. ❄

   

However, this is the pub run, and it's also Friday night, so it's most likely drunk and will probably disappear the next morning...

[northwestsnow]

Stunning run...

Very cold everywhere with some harsh frosts...

[SMU]

Rain approaching from the SW will soon turn to snow when it hits air with -10c dewpoints !

Edited November 27, 2020 by Steve Murr

[feb1991blizzard]

18z GFS could end up an absolute stonker.

[Eskimo]

Looking really blocked.

[northwestsnow]

Icelandic high /Euro low is a nice combo !!

[Met4Cast]

BEAUTIFUL, BEAUTIFUL run from the 18z GFS tonight. Everything goes so smoothly, we get a Griceland ridge, first run to show widespread snow potential in the form of slider lows AND then we see the pattern sustaining. Beautiful.

Shame it's;

1. The GFS

2. Completely different from the previous run

3. The 18z.

[Matt H]

Beautiful, finally some uppers worth tapping into!

[Eskimo]

High just needs to be 1000 miles west and it would a pub run special!! 

 

[Zak M]

18z GFS gets the -8c isotherm reaching as far south as Cambridge on day 10 -

Edited November 27, 2020 by Zak M

[BelgianBlizzard]

8 minutes ago, PerfectStorm said:

High just needs to be 1000 miles west and it would a pub run special!! 

 

I'd still like to bank this run... Negative uppers starting 120+ and getting colder and colder

Edited November 27, 2020 by Roeland De Raeymaeker

[Gowon]

Very cold chart but it's dry

[Tim Bland]

Just need a shift 500 miles west and we are in business. Failing that a NE flow to bring some snow showers inland. Lots to play for on future runs...

[Eskimo]

4 minutes ago, Roeland De Raeymaeker said:

I'd still like to bank this run... Negative uppers starting 120+ and getting colder and colder

Welcome to the forum 

Yup, any air that isn't coming from the SW and accompanied by liquid is a bonus in my opinion. 

[SMU]

Pretty good Mean @192 semi supportive of the operational !

Only 1 or 2 atlantic runs - The rest Northerly or Easterly ( PTB 25 ! )

 

[Duane S.]

Wedgetastic 18z.

This eagerness to drop energy N-S is very encouraging indeed. I never mind seeing that happen to our west initially. I’m definitely getting a winter 2012/13 vibe...

[Trom]

3 hours ago, Mike Poole said:

Looks like a direct hit from the north on the JMA T192:

Good 12z output today, confirms the view we are in the game, and probably will be for a few weeks if the strat and trop vortexes stay disconnected, actually getting more so on the NAM plot, based on todays GFS 0z:

Thereafter, the scene seems to be set for a possible SSW with the Aleutian low, Russian high combo, a significant precursor, so recurring in the output, illustrated on the ECM T240 chart:

With the start of winter only 4 days away, coldies could hardly have more irons in the fire, so to speak...

 

We would be wanting a slow response from any SSW at the current point.  Right now I'd like to see how the current scenarios play out.  So much more promising than in past years.  I always visualise that a SSW is like breaking at pool - bits of vortex are going to fly but exactly where and when is always the issue. Like a reset button. If the trop and strat vortexes couple any time soon I'll be praying for the SSW, but coupling doesn't seem to be on the cards early winter.  Traditionally snowy weather before Jan gets progressively less probable the further South you go, largely because the NW feed doesn't have bite.  For those of us in the South the Easterly is king and you can't expect a developed cold pool just yet.  Personally I'm excited - it's only late November.  I think the most important thing is to remember there are no guarantees even when the odds look better.

[Daniel*]

13 minutes ago, s4lancia said:

Wedgetastic 18z.

This eagerness to drop energy N-S is very encouraging indeed. I never mind seeing that happen to our west initially. I’m definitely getting a winter 2012/13 vibe...

I echo your sentiments January 2013 the last prolonged cold spell in London several big snow events not remarkable synoptics but they delivered. 

[SMU]

Night all-

PTB 20 worth a shout out for rarity.

-18c uppers touching shetland & -20c uppers for Faroe Is. 

Edited November 27, 2020 by Steve Murr

[Allseasons-Si]

Hi guys,late to the mad party...again and there isn't that much to say or add as all of you guys have said it/shown it and a great read too

i would just like to add that the JMA (NH) wise is looking good with eastern USA trough with WAA up into west Greenland from day ten>

fantastic synoptic charts on offer today but there is some discrepancies in terms of how far south this trough digs down through or near the UK 144-168 hrs and a number of outcomes are still possible.

 

Edited November 27, 2020 by Allseasons-si

[kold weather]

Well its the hope that keeps you going I suppose!

Very solid 18z GFS op run. We would be looking at a decent length cold spell should that come off. It collapses fairly quickly but I'd suspect you'd probably get a repeat episode a little deeper into December, especially there is some decent long term support for that.

A long old way to go yet mind you and the last few years haven't exactly been great for these sorts of things.

[joggs]

3 minutes ago, Steve Murr said:

Night all-

PTB 20 worth a shout out for rarity.

-18c uppers touching shetland & -20c uppers for Faroe Is. 

Yes, we see this promise most winters that never come off. We have to temper expectations imo.

Mo further outlook isn't to priming.

And they are the  real deal.

[Don]

4 minutes ago, joggs said:

Mo further outlook isn't to priming.

And they are the  real deal.

If these signals remain consistent for the next few days, their outlook will change.

[Geordiesnow]

As usual in these situations, unless we see a decent Atlantic ridge, then the threat of cold will always be marginal at best and we seen many times of ridges in the medium term getting downgraded which ruins the cold pattern. 

At least the west based NAO set up has been dropped though and this is why the northerly threat has increased but too early to say if the UK will turn significantly colder or not.