Model Output Discussion - Into Winter

[ICE COLD]

4 minutes ago, bluearmy said:

Strong split reversal on the 06z and a slow burner in the trop that looks primed for retrogression in week 3 

Yep  

[johncam]

2 hours ago, Kentspur said:

You're fine up in Scotland looks primed for some atleast temporary snowfalls being that far north.

Anyway wheres our ECM clusters brigade to bring us some festive cheer?

Not in central belt I am afraid,   anyhoo everyone have a great day  off on cooking  duties

[tight isobar]

Merry Christmas .. one n, All. And the output should soon start strong assumptions on the upper layers .. have a good en.    

Edited December 25, 2023 by tight isobar

[swfc]

2 minutes ago, tight isobar said:

Merry Christmas .. one n, All. And the output should soon start strong assumptions on the upper layers .. have a good en.    

All the best pal. Nice to see you back

[lorenzo]

Merry Xmas all - have a magical day ! Some fun modelling ahead for NWP geeks, nice Xmas gift for 2023 and early 2024 !

[Eagle Eye]

Merry Christmas everyone, latest GFS ends with a significant split and a large reversal of zonal winds. Pretty much every run now is headed in that sort of direction, we've seen it go wrong before but for now, enjoy the festive cheer in the models. 

Given that it's a significant wave-1 perhaps weak wave-2 that's strong enough to split the vortex on this run, then if we get something similar, it could be a pretty major Stratospheric event. Not often we get a Wave-1 strong enough to completely thermally cut through the vortex. The release of energy from the Ural omega block is clearly having some potential. Would be an interesting case study if it were to occur. If the models keep modelling this with mot much impact from the attempted Greenland warming and more the Ural-north Pacific wave, I'll probably go in-depth at some point. For now, enjoy it. 

Edited December 25, 2023 by Eagle Eye

[BartyHater]

It might be 384 and into the middle third of Jan, but the P word can probably be used here….at last.

Hopefully that P will be realised in the 2nd half of the month and into Feb.

[DaveF]

52 minutes ago, snowspotter said:

Presume we’re looking at the average red dotted line ? If so believe it shows a warming (moderate) early January ? Am. Correct . The purple line obviously goes off on one but not until April so that’s no use 

I think you’re misreading the plot. It’s not showing temperature, it’s showing the westerly component of stratospheric wind. An SSW leads to this falling below zero (reversal to easterly). The OP refers to the GEFS which is the green. Red is not an average, it is what happened last year.

[blizzard81]

A very merry Christmas to all my winter (and mild lol) lovers on this great forum ❄❄♥♥. I hope you all have a fantastic day with your loved ones. Love and peace to you all ❤ ❤ xxx

[swfc]

Blessings to everyone. Good times ahead next year for everyone and hopefully some great weather, whatever your preference

[Kentspur]

23 minutes ago, BartyHater said:

It might be 384 and into the middle third of Jan, but the P word can probably be used here….at last.

Hopefully that P will be realised in the 2nd half of the month and into Feb.

As expected GFS 6z op run an outlier towards the end (full ensembles not out just yet on wetterzentrale) but trending colder for north and south alike

Edited December 25, 2023 by Kentspur

[AO-]

Merry Christmas everyone.

Just a comparison between the last two EPS of the GFS. The difference is huge. The 00 being s lot colder. This is the 2m for my location. Something about the reliability of the GFS6?

It's a real chaos. 

Edited December 25, 2023 by AO-

[Lukesluckybunch]

Morning everyone,merry xmas!Gfs anomolie chart at the end of its run is amazing..so much reds around Greenland

[Kasim Awan]

Very poor ECM 00Z and GFS 06Z. Strong Iberian heights.

[Rickstar]

28 minutes ago, BartyHater said:

It might be 384 and into the middle third of Jan, but the P word can probably be used here….at last.

Hopefully that P will be realised in the 2nd half of the month and into Feb.

What is p please?

[Kasim Awan]

10 minutes ago, Lukesluckybunch said:

Morning everyone,merry xmas!Gfs anomolie chart at the end of its run is amazing..so much reds around Greenland

It feels to me like charts beyond 240 hours are being taken way too seriously. They are nothing more than cannon fodder. An optimal SSW response for the UK is 5050 with a tropospheric vortex the strength it is currently.

[That ECM]

8 minutes ago, Kasim Awan said:

It feels to me like charts beyond 240 hours are being taken way too seriously. They are nothing more than cannon fodder. An optimal SSW response for the UK is 5050 with a tropospheric vortex the strength it is currently.

Within the 31 there’s many pretty “cannon fodder” which leads to a lovely mean”

Edited December 25, 2023 by That ECM

[Kasim Awan]

I don't think a major SSW and polar vortex split will reduce the strength of the Azores high much. The jet stream yes, but that high pressure system is driven by other telleconnection factors which can't change as quick. Some short sharp cold spells still seem possible if we get the SSW and PV split but anything prolonged looks unlikely for this reason.

[Tamara]

Feliz Natal e todos

The strong Iberian heights have created a persistent inversion that has led to some very cold nights in parts of inland NE Portugal. Municipio de Bragança has seen some consecutive sub zero nights and freezing fog leading to rime deposits & Christmas card appearances. By contrast parts of the Algarve have seen maximum day values close to 18C. Locally to me the nights have been down to about 4C and daytimes around 14C.

Seeing festive pictures like this is quite the contrast to the 35C to 40C heat under similar pressure patterns in summer!

Much documented on this thread obviously but January is shaping up to do the opposite of how Dec/Jan 22/23 panned out. Quite a growing signal for a southerly tracking jet replacing eventually the anticyclonic inversion conditions in Iberia and blocking to the north of Europe. Not a day for any analysis, but hope all have a lovely day and best wishes for 2024

[Kentspur]

1 minute ago, Kasim Awan said:

I don't think a major SSW and polar vortex split will reduce the strength of the Azores high much. The jet stream yes, but that high pressure system is driven by other telleconnection factors which can't change as quick. Some short sharp cold spells still seem possible if we get the SSW and PV split but anything prolonged looks unlikely for this reason.

The ensembles must be seeing something the GFS op was mostly a warm outlier anyhow im keeping the faith and happy to wait it out...

[Kasim Awan]

2 minutes ago, That ECM said:

Within the 31 there’s many pretty “cannon fodder” which leads to a lovely mean”

At that range it means nothing. Models loose grasp on the main driving pressure systems by around 240h.

Just now, Kentspur said:

The ensembles must be seeing something the GFS op was mostly a warm outlier anyhow im keeping the faith and happy to wait it out...

I think a few temporary cold snaps mid month, CET will likely be between 4 and 5.5C.

[Lukesluckybunch]

5 minutes ago, Kasim Awan said:

At that range it means nothing. Models loose grasp on the main driving pressure systems by around 240h.

I think a few temporary cold snaps mid month, CET will likely be between 4 and 5.5C.

That's not great then..we need a CET of between 1.5 and 2.5c..that would make most of us happy

[Kasim Awan]

Just now, Lukesluckybunch said:

That's not great then..we need a CET of between 1.5 and 2.5c..that would make most of us happy

If you think the CET will end up between 1.5 and 2.5 you're in cloud cukoo land really.

[Lukesluckybunch]

19 minutes ago, Kasim Awan said:

It feels to me like charts beyond 240 hours are being taken way too seriously. They are nothing more than cannon fodder. An optimal SSW response for the UK is 5050 with a tropospheric vortex the strength it is currently.

That's right kasim..and them particular charts often look a lot better then they are!and I agree it's probably a little too far out too take seriously

[That ECM]

2 minutes ago, Lukesluckybunch said:

That's not great then..we need a CET of between 1.5 and 2.5c..that would make most of us happy

It’s absolutely fine. None of us including Kasim are in control.

Edited December 25, 2023 by That ECM