Model Output Discussion - Into Winter

[chris55]

Merry Xmas eve ️!

[mountain shadow]

Impressive inter run consistency from the GFS.

Hopefully it continues..

[Guest]

  Bing, clear your throat son! 

[Dennis]

The vortex coldplunge 

[John88B]

Pretty good model consistency now and loving the positivity in here this morning

Hopefully soon a more positive, definitive update from the met office for a cold, seasonal and maybe snowy Christmas period

[That ECM]

Come on ecm read the script.

[nick sussex]

Just now, That ECM said:

Come on ecm read the script.

The best that can be said for the ECM is the weakening and fragmenting of the PV .

At least the monsoon rains will come to an end with the country having a chance to dry out.

[Nick F]

Morning. Nice to see 00z GFS op in a festive mood with a wintry look to start Christmas Eve.

I suppose, ideally, we see the high building NE from the Azores gain high enough latitude to keep it calm and chilly, with night frosts and develop some surface cold, before the high migrates NW and an upper trough drops SE into Scandinavia and thus opens up the doors to the arctic in time for Xmas.

However, 00z EC continues to show the high not gaining enough latitude so we end up with a mild and possibly cloudy flow off the Atlantic - especially further north, south maybe clearer and frosty.

[Nick2373]

 

00z the consistency is remarkable its all about trends and you couldn't get a finer trend to what this as been pumping out the last few days, the 23rd is a long way off in forecasting terms FI If you like. but hopefully we will see this trend next week then we could see some pre Xmas excitement But!! remember its like a roller coaster loads of twists and turns and most importantly  keep your arms and legs in the car because to much excitement could lead to disappointment. If i remember it was the year before last when the models were showing a Xmas nirvana only to have it stolen away from us in 24hrs.   

[Dennis]

14 minutes ago, Nick F said:

 

However, 00z EC continues to show the high not gaining enough latitude so we end up with a mild and possibly cloudy flow off the Atlantic - especially further north, south maybe clearer and frosty.

hope is comes off to a big blocking to greenland and create a plunge (MJO8)

Edited December 8, 2023 by Dennis

[Chesil View]

6 minutes ago, Nick F said:

Morning. Nice to see 00z GFS op in a festive mood with a wintry look to start Christmas Eve.

I suppose, ideally, we see the high building NE from the Azores gain high enough latitude to keep it calm and chilly, with night frosts and develop some surface cold, before the high migrates NW and an upper trough drops SE into Scandinavia and thus opens up the doors to the arctic in time for Xmas.

However, 00z EC continues to show the high not gaining enough latitude so we end up with a mild and possibly cloudy flow off the Atlantic - especially further north, south maybe clearer and frosty.

Excellent gfs 0z. Ecm I think will get there as well just a day or two slower on the evolution.

Ecm does still have the pv fragmenting that will create the space for our high to move north/northwest/northeast

[joggs]

We'll,it was the GFS that picked up our previous cold spell first so hope it's on the money. I think the ECM will get there.

The northern hemisphere looks primed for retrogression of the pattern from day 10, especially with some good background signals showing the same.

Slowly slowly....

Edited December 8, 2023 by joggs

[carinthian]

51 minutes ago, Nick F said:

Morning. Nice to see 00z GFS op in a festive mood with a wintry look to start Christmas Eve.

I suppose, ideally, we see the high building NE from the Azores gain high enough latitude to keep it calm and chilly, with night frosts and develop some surface cold, before the high migrates NW and an upper trough drops SE into Scandinavia and thus opens up the doors to the arctic in time for Xmas.

However, 00z EC continues to show the high not gaining enough latitude so we end up with a mild and possibly cloudy flow off the Atlantic - especially further north, south maybe clearer and frosty.

Yes Nick, UKMO at 168t does offer some lower temps over the SE . I would think the high is primed to centre over Southern England this time next week . So hopefully some surface cold over Southern England. Oh, then there is the small matter of the lead up to Christmas week. GFS extended trends to a Fairy Tail Christmas in the making, whilst ECM heading for a milder bore fest ! Of course both could be wrong. However, the early winter form winner so far has been GFS to pick out trends to cold or return to mild. Hopefully, its on the mark with its current runs to bring the upper trough down across Scandiland post medium term and let the cold flood south.

 

C

Edited December 8, 2023 by carinthian

[offerman]

This is so far out and of course a lot of things can change and I normally take charts so far away with a pinch of salt but the reason I’m posting this screenshot is to show how there is no azores / iberian high around whatsoever which is exactly what you want for the cold to come down nicely and flood all the way down into France and beyond ( no hold ups just a clear path through the uk , and this chart looks like one of the old classic cold spell setups if it just can verify would be amazing!! 

Edited December 8, 2023 by offerman

[Mike Poole]

Clusters this morning look messier than yesterday.

T192-T240:

High starting to head northwest on clusters 1 and 4, northeast on cluster 5.

T264+:

High looks to migrate northwest on the first 3, cluster 3 looks the most promising.  Cluster 4 hedges its bets with heights to northeast and northwest.  All variations on a theme at this range, so on to the next set of runs…

[Purga]

A pleasant Xmas if the Op verifies in FI. At least it'll be fun over the next few days or so instead of wrist slitting Bartlettism !

[LRD]

7 minutes ago, Mike Poole said:

Clusters this morning look messier than yesterday.

T192-T240:

High starting to head northwest on clusters 1 and 4, northeast on cluster 5.

T264+:

High looks to migrate northwest on the first 3, cluster 3 looks the most promising.  Cluster 4 hedges its bets with heights to northeast and northwest.  All variations on a theme at this range, so on to the next set of runs…

Hmmm, those 264+ clusters look a bit disappointing

Most populous clusters have a +NAO although cluster 2 might be setting up something wintry in time for Xmas Day

[Anthony Burden]

1 hour ago, Nick F said:

Morning. Nice to see 00z GFS op in a festive mood with a wintry look to start Christmas Eve.

I suppose, ideally, we see the high building NE from the Azores gain high enough latitude to keep it calm and chilly, with night frosts and develop some surface cold, before the high migrates NW and an upper trough drops SE into Scandinavia and thus opens up the doors to the arctic in time for Xmas.

However, 00z EC continues to show the high not gaining enough latitude so we end up with a mild and possibly cloudy flow off the Atlantic - especially further north, south maybe clearer and frosty.

Morning Nick all credit to GFS for picking up this pressure rise over the UK while Exeter /Glosea was not at all on this wave length.

[Anthony Burden]

Morning all,interesting Geffs ensembles this morning with possible Greenland high around Christmas and a great chance of the white stuff,long way out but at least a hope of a white Christmas.back to the next week or so if the skies stay clear fog and frost for the south could be on the cards.

[bluearmy]

2 hours ago, Dennis said:

The vortex coldplunge 

not really for us dennis - probably ok over n U.K. with such low dam 

you guys in Norway though ……..
 

[Jeremy Shockey]

GFS 0z for Christmas Eve

Well this would be fun if it came off !

[BartyHater]

Feet firmly on terra firma here....any interest beyond the general dry up still lies deep in FI and those 264hr clusters posted by @Mike Poole show a sinker definitely can't be dismissed as an option - how could it be at this range?

So whilst things look encouraging it's steady as she goes, more runs needed etc, etc...we know the drill by now.

[ITSY]

A lot of comments this morning on the poor ECM vs good GFS. But they extend to wildly different timeframes, and the point of interest is pretty much only after ECM stops. For argument sake, this is the good GFS at +216: 

And this is the bad ECM at +240: 

There are clear upstream differences that will affect later frames, but they are not oceans apart. The broad pattern is similar, and indeed there's a case to be made that the ECM has actually done a better job at that range of shifting parts of the PV toward Scandinavia. The point I'm making is that we're still a very long way away from being able to identify medium-term cross-model support. By the time the period of interest gets to +216/+240 then we can start worrying about X-Model support. For now, it's just building blocks and trends that we're looking for. 

[bluearmy]

1 hour ago, joggs said:

We'll,it was the GFS that picked up our previous cold spell first so hope it's on the money. I think the ECM will get there.

The northern hemisphere looks primed for retrogression of the pattern from day 10, especially with some good background signals showing the same.

Slowly slowly....

Tbf, the extended ens have picked this first with gem leading the way.  Wrt ops, it will always be gfs first that picks cold with four runs per day to day 16

40 minutes ago, Mike Poole said:

Clusters this morning look messier than yesterday.

T192-T240:

High starting to head northwest on clusters 1 and 4, northeast on cluster 5.

T264+:

High looks to migrate northwest on the first 3, cluster 3 looks the most promising.  Cluster 4 hedges its bets with heights to northeast and northwest.  All variations on a theme at this range, so on to the next set of runs…

There is enough variation from suite to suite and across big clusters to make this evolution uncertain as we approach Xmas.  I’d also like to see a control run which shows the general theme - we had a northerly a couple days ago but was an accelerated evolution so didn’t fit with the general ens timescale.  

[BartyHater]

9 minutes ago, ITSY said:

A lot of comments this morning on the poor ECM vs good GFS. But they extend to wildly different timeframes, and the point of interest is pretty much only after ECM stops. For argument sake, this is the good GFS at +216: 

And this is the bad ECM at +240: 

There are clear upstream differences that will affect later frames, but they are not oceans apart. The broad pattern is similar, and indeed there's a case to be made that the ECM has actually done a better job at that range of shifting parts of the PV toward Scandinavia. The point I'm making is that we're still a very long way away from being able to identify medium-term cross-model support. By the time the period of interest gets to +216/+240 then we can start worrying about X-Model support. For now, it's just building blocks and trends that we're looking for. 

Good post/point....neither look primed or guaranteed to see the High drifting N, the GFS op simply shows us one way it could/may/might in FI.