Stratosphere and Polar Vortex Watch 2020

[SqueakheartLW]

On 06/12/2021 at 20:39, Griff said:

Oh joy 

 

On 06/12/2021 at 21:42, Griff said:

@Dennis what do we have here... 

 

Right at the end of this chart is what I'll take.

Although we don't necessarily need a weak or reversed polar vortex to get a colder winter. A good example is 1995/1996

Generally at or above average throughout that season and look how that winter turned out

[Griff]

1 minute ago, SqueakheartLW said:

Right at the end of this chart is what I'll take.

Negative anomaly so easterly? 

[Dennis]

7 minutes ago, Griff said:

@Dennis what do we have here... 

 

Like we see now an strato-tropo connection on a westerly base will it come later the month to easterly connection...see for example NAM -3 its now 2 positiv

.

[DavidS]

GFS has been showing a significant strat warm in FI for the last few runs. I’d like to see this modelled within D10, but it is interesting nonetheless. 
 

The last frame below even hints at a split.

 

[Singularity]

We’re seeing GFS start to explore the impacts of the high amplitude W Pacific MJO. A significant warming likely, possibly SSW but remains to be seen. Main caveat is that the model tends to be a bit too quick to begin with, actual outcome being a week or two slower to reach peak warming.

[bluearmy]

1 hour ago, DavidS said:

GFS has been showing a significant strat warm in FI for the last few runs. I’d like to see this modelled within D10, but it is interesting nonetheless. 
 

The last frame below even hints at a split.

 

More than a hint a little lower down and a little moreso as you head further down 

would look to be trop induced bottom up so not something to hang your hat on just yet! 

 

Edited December 7, 2021 by bluearmy

[Kirkcaldy Weather]

1 hour ago, bluearmy said:

More than a hint a little lower down and a little moreso as you head further down 

would look to be trop induced bottom up so not something to hang your hat on just yet! 

 

Merely adding to the discussion rather than saying he'll be correct but Joe is thinking of a split 

 

[bluearmy]

2 hours ago, bluearmy said:

More than a hint a little lower down and a little moreso as you head further down 

would look to be trop induced bottom up so not something to hang your hat on just yet! 

 

No surprise to see this gone on the 12z with no trop split to work it’s way up 

what the 06z does show is that the trop is still leading the dance ……..

[Singularity]

Interesting that a fair bit of stratosphere warming has manifested in the 8-12 day range of GFS for a change, rather than having to be chased from 14+ days lead time.

Hints that subsequent pulses are needed to really hammer the polar vortex... but with a weak EP Nina, P6-P7 MJO setup, merely keeping the polar vortex from becoming strong opens up mid-high latitude blocking high progression possibilities, such as the classic UK/Scandi => Iceland/Greenland one.

[Singularity]

Seems GFS has been a bit too quick as usual to build up the warming in the stratosphere - but to its credit, it's still there, now starting almost within the reliable range for the stratosphere. A second, stronger surge showing up in the 14-16 day range, but of course, it remains to be seen how much that holds.

Doubtless that the polar vortex will come under fire repeatedly while the pattern remains highly perturbed by the slow-moving MJO wave in the tropical Pacific.

Funnily enough, GFS' backing down in the stratosphere seems to be working in favour of blocking to the N or NW of the UK in the troposphere, as it was previously showing some 'flushing down' of zonal winds having displaced the polar vortex toward the North Atlantic, which was resulting in a surge of westerlies there.

Considering what extended ECM/EPS runs have been up to of late, I wonder if a similar story has played out there - or it may just be the usual drift toward climatology slowly being overridden as the tropical signal becomes better resolved.

[Catacol]

2 minutes ago, Singularity said:

Seems GFS has been a bit too quick as usual to build up the warming in the stratosphere - but to its credit, it's still there, now starting almost within the reliable range for the stratosphere. A second, stronger surge showing up in the 14-16 day range, but of course, it remains to be seen how much that holds.

Doubtless that the polar vortex will come under fire repeatedly while the pattern remains highly perturbed by the slow-moving MJO wave in the tropical Pacific.

Funnily enough, GFS' backing down in the stratosphere seems to be working in favour of blocking to the N or NW of the UK in the troposphere, as it was previously showing some 'flushing down' of zonal winds having displaced the polar vortex toward the North Atlantic, which was resulting in a surge of westerlies there.

Considering what extended ECM/EPS runs have been up to of late, I wonder if a similar story has played out there - or it may just be the usual drift toward climatology slowly being overridden as the tropical signal becomes better resolved.

Flux vectors look a bit better to me today

 

and at the outer edge of reality we have decent wave 2 pinching.

Euro from yesterday sees a modest signal for wave 2 also just before Xmas

Whether all this will be enough to force a SSW I doubt - for me it will be round 2 before that might happen….but it may just do enough to make New Year interesting before our MJO forcing fades.

 

[DavidS]

GFS continuing to show a significant double warming at 10hpa. Snapshots here from the 00z at days 6 and then 12.

[sebastiaan1973]

https://twitter.com/WorldClimateSvc/status/1470758090408660995

[mushymanrob]

18 hours ago, sebastiaan1973 said:

https://twitter.com/WorldClimateSvc/status/1470758090408660995

but february 1980 was mild....

 

[Pixel]

Just noticed this little feature predicted over us... seems kind of sudden.. any thoughts on influence further down the line ?

[bluearmy]

Marco tweeted something about the strat the other day - was a bit cryptic and based on gfs. I wondered if glosea was seeing something 

todays 00z gfs slows the spv markedly late on below 30 m/s at day 16 and at the top of the strat we are down to 10m/s with a displacement ssw look 

One to watch ……. 

whilst the spv and tpv remain uncoupled, this cannot go on forever and to have a quiet strat through Jan would help cold chances in the trop 

[Uncertainty]

45 minutes ago, bluearmy said:

Marco tweeted something about the strat the other day - was a bit cryptic and based on gfs. I wondered if glosea was seeing something 

todays 00z gfs slows the spv markedly late on below 30 m/s at day 16 and at the top of the strat we are down to 10m/s with a displacement ssw look 

One to watch ……. 

whilst the spv and tpv remain uncoupled, this cannot go on forever and to have a quiet strat through Jan would help cold chances in the trop 

Quite a few GEPS members looking pretty stretched up top as well late on, though obviously the 0z gfs is a huge outlier. 

I know there’s been some heat flux and wave 2 into the strat recently but not enough to trigger an SSW?

MP first mentioned this around a week ago? I haven’t heard many of the strat gurus mention much? 
 

My concern would be some sort of stretching towards the NA side giving them a cold January and us a rampant jet… 

Tell me I needn’t worry blue!

[bluearmy]

22 minutes ago, Uncertainy said:

Quite a few GEPS members looking pretty stretched up top as well late on, though obviously the 0z gfs is a huge outlier. 

I know there’s been some heat flux and wave 2 into the strat recently but not enough to trigger an SSW?

MP first mentioned this around a week ago? I haven’t heard many of the strat gurus mention much? 
 

My concern would be some sort of stretching towards the NA side giving them a cold January and us a rampant jet… 

Tell me I needn’t worry blue!

On the eastern edge of a warm ocean with the earth turning in our direction …….what’s there to worry about ??.

[SqueakheartLW]

This was today's 00z OP at the end of the run. A bit stretched out I must say

A few of the 00z ensembles also caught my eye too

Edited December 19, 2021 by SqueakheartLW

[Catacol]

Just signs now that pressure may begin to tell on the Strat. It has been a slow start - but it may pick up pace. GFS at the outer edges of reality forecasting a significant amount of poleward flux in the lower strat

and the Berlin charts starting to signal a ramping up of wave attacks on the vortex in the 10 day period. Here the wave two chart for the New Year, not too many hours before that GFS flux chart. 

January looks full of interest....in a season so far full of the same!

 

Edited December 20, 2021 by Catacol

[ALL ABOARD]

She's starting to struggle

[Don]

9 minutes ago, ALL ABOARD said:

She's starting to struggle

Could come at just the right time?!

[SqueakheartLW]

Here's the spread of maximum warming temperatures on the 06z GFS and it's ensembles

Temp    Member                           
-32        19
-28        Op,12
-24        23
-20        01,06,08,11,20,28,30
-16        Ct,07,14,15,16,18,26,27
-12        02,03,04,13,17,22,25
-8          05,09,10,29
-4          24
0           21                                       

Average warming temp max = -16.13C

A decent warming showing up with most members clustered between -12 and -20 as a max warming level.

Could do with shifting the mean warmer than this however, closer to 0C or even above freezing at maximum warming level, a bit like the 2 warmest members in the 06z

[Paul_1978]

On 21/12/2021 at 10:57, ALL ABOARD said:

She's starting to struggle

At least it's not at T+384 as is often the case so that's a positive in my book!!

[joggs]

8 minutes ago, Paul_1978 said:

At least it's not at T+384 as is often the case so that's a positive in my book!!

I'm banking on this this winter tbh.

I wonder if the MO further has this tied in(Jan)?.

Edited December 22, 2021 by joggs