Model Output Discussion - Into Winter

[warrenb]

GFS has the jet fired up and the PV in Greenland, game over if that is the case.

[northwestsnow]

Well clearly some divergence on timing on any breakdown  so clarity will have to wait another day.

Ideally no breakdown at all

 

[Mike Poole]

3 minutes ago, Stravaiger said:

Although it doesn't look great on the face of it, I'm really encouraged by the GEM evolution on today's 12Z.

It ends up with the heights/cold in Scandi holding firm, forcing energy from the Atlantic to disrupt SE into C. Europe, which will ultimately open the door to heights in the north retrogressing and, at the very least, giving us coolish zonality without the awful Iberian / Bartlett high that has plagued recent winters.

Plausible outcome and preserves the awesome Scandi cold pool - we could do worse!

Yes, agree, this is the scenario I was on about earlier, which is a very plausible outcome - much more than the GFS 12z in FI.

[sorepaw1]

14 minutes ago, bluearmy said:

I think that unless we get a ‘wtf ukmo’ run like we saw a decade ago then this is heading in one direction. That infamous ukmo run found a wedge at day 4/5 which sent the atlantic lw trough se and kept the whole country in the cold air.  You’d expect modelling to have advanced a fair bit since then though.

Just an observation but I found charts more reliable 19 years ago than nowadays,  I don't know if there's any substance to this.

Or there's just to much data and technology these days.

I won't proclaim to knowing this accurately, it's just my take.

[Vikos]

GFS under too much statistic influence (hyping the atlantic, I hope)

[sheikhy]

Big changes on the mean at 168 hours!!atlaltic further west and also control disrupts at 168 hours!!better than the op!!need ecm to show the same though!!

[Uncertainty]

24 minutes ago, bluearmy said:

I think that unless we get a ‘wtf ukmo’ run like we saw a decade ago then this is heading in one direction. That infamous ukmo run found a wedge at day 4/5 which sent the atlantic lw trough se and kept the whole country in the cold air.  You’d expect modelling to have advanced a fair bit since then though.

A surprising amount of GEFS members do just that Nick. At least 11 look to block off the Atlantic quite strongly at 150. 
 

My experience tells me @IDOis on the money but while there’s a chance… there’s a chance…

[booferking]

Wouldn't be calling anything for a few days yet very volatile anything could happen some very blocked gefs.

 

https://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=168

[feb1991blizzard]

just as exeter says no, GEFS say yes to a wedge.

[Jackski4]

Just now, feb1991blizzard said:

just as exeter says no, GEFS say yes to a wedge.

Seems that all Exeter do these days is play catch up!

[Premiere Neige]

1 hour ago, Blessed Weather said:

 

 

Thanks guys. The frustration of scientific papers that are behind a paywall and you can only read the abstract and first page. The abstract says "The stratospheric warming and circulation change of January and February 1963 are discussed.......    ........warming initially appeared at 10mb over southeastern Canada.......  ......the subsequent events..... .....destruction of the wintertime polar cyclone......"

And the last sentence of the first page says "Beginning in mid-January 1963 the stratospheric circulation was interrupted by intense temperature and height changes of a scale as large as any previously documented".

I concluded the Canadian warming was early January, leading to a full-blown SSW late February, but I'm happy to accept that the Canadian Warming was in November, leading to the above in Jan/Feb. Have you guys got a source of info to confirm Nov 1962 please? There are precious little scientific papers on the phenomenon, although last week Prof. Judah Cohen stated he was involved in a study, so that's good news.

Whatever, for those of us with a cold persuasion, let's keep our fingers crossed that this Canadian Warming has a similar impact to the winter of 1963.

On Gavs Weather Vids during last years winter updates he talked about it and did a reanalysis section (can't remember which model) but the Canadian warming was definitely November 1962.

[booferking]

36 minutes ago, feb1991blizzard said:

just as exeter says no, GEFS say yes to a wedge.

The thing is Exeter didn't say no and mentioned alot of uncertainty?

Edited November 29, 2023 by booferking

[Mike Poole]

Just now, Jackski4 said:

Seems that all Exeter do these days is play catch up!

In a very uncertain situation, I’ve never quite understood why Exeter’s view on yesterday’s runs is considered to be pertinent to our view of the runs rolling out right now.

[Bristawl Si]

3 minutes ago, Jackski4 said:

Seems that all Exeter do these days is play catch up!

Erm...that chart is 8 days away

[Robin2012]

4 minutes ago, booferking said:

Wouldn't be calling anything for a few days yet very volatile anything could happen some very blocked gefs.

 

https://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=168

Which is exactly what met and beeb have been saying today but many with their ‘Pat me on the back told you so agendas ‘  have conveniently forgotten

[Bats32]

Fwiw, Exeters 10 dayer last week was completely wrong for this week.

[snowblind]

Just now, Jackski4 said:

Seems that all Exeter do these days is play catch up!

That's the trouble with issuing long range forecasts. The further ahead you go the less likely you are to be correct. Then you have to change it everyday to keep it semi accurate. The way the models change it doesn't seem worth going more than a week ahead.

[johnholmes]

No charts to show but worth remembering that prior to computers weather forecasters (me included) often moved milder air too quickly in to replace deep cold air. The huge and very complex weather models of today are often guilty of a similar error. Once deep cold is well organised then warm air finds it more difficult than the very complex hydrostatic equations would suggest. I'm not saying it will occur in this instance but depending on how long and how cold the air gets over the UK it is something to watch for.

[LRD]

7 minutes ago, snowblind said:

That's the trouble with issuing long range forecasts. The further ahead you go the less likely you are to be correct. Then you have to change it everyday to keep it semi accurate. The way the models change it doesn't seem worth going more than a week ahead.

Damned if they do, damned if they don't

I think the Met Office do a terrific job most of the time but they do no right in some people's eyes. Get 8 out of 10 things right and are criticised for the 2. Weird

Anyway, another warm op run obviously with 2 distinct clusters setting up. Interesting. Short ensembles:

Edited November 29, 2023 by LRD

[Snowy L]

10 minutes ago, LRD said:

Damned if they do, damned if they don't

I think the Met Office do a terrific job most of the time but they do no right in some people's eyes. Get 8 out of 10 things right and are criticised for the 2. Weird

Anyway, another warm op run obviously with 2 distinct clusters setting up. Interesting. Short ensembles:

That's a significant cold cluster at least, what's that 65/35 in favour of mild.

[LRD]

2 minutes ago, Snowy L said:

That's a significant cold cluster at least, what's that 65/35 in favour of mild.

Yeah, I'd say it's about that. Maybe 70-30

It continues deeper into the ensemble run

Edited November 29, 2023 by LRD

[Marting]

11 minutes ago, LRD said:

Damned if they do, damned if they don't

I think the Met Office do a terrific job most of the time but they do no right in some people's eyes. Get 8 out of 10 things right and are criticised for the 2. Weird

Anyway, another warm op run obviously with 2 distinct clusters setting up. Interesting. Short ensembles:

Yes, ensembles are showing an increasing battle between scandi high and more mobile weather. Watching the trends! 

[Mike Poole]

5 minutes ago, Snowy L said:

That's a significant cold cluster at least, what's that 65/35 in favour of mild.

If the EPS show the same thing later this afternoon, the game’s right back on…

Edited November 29, 2023 by Mike Poole

[The Enforcer]

2 hours ago, MattStoke said:

Weekend trough popping up again on the ICON.

1 hour ago, Tim Bland said:

GFS similar to icon with a cm or 2 for some Sat night into Sunday morn 

 

 

Model output in "Cold spell might produce some non-frontal lowland snowfall" shocker.

Edited November 29, 2023 by The Enforcer

[TSNWK]

59 minutes ago, warrenb said:

GFS has the jet fired up and the PV in Greenland, game over if that is the case.

Hello.. please can you post charts? I do find these brief "HEADLINE' actually rather disingenuous to the many on here who put a lot of effort offering a view.

To keep it model related please can elaborate on "Game over" is that cold for next week? December? Winter? Life?

Thank you.