Stratosphere and Polar Vortex Watch 2020

[joggs]

21 hours ago, SqueakheartLW said:

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

Appreciate this.

[SqueakheartLW]

GFS 06z 21/12/2021

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

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

GFS 06z 22/12/2021

How does today's GFS compare with the 06z yesterday. Below we have today's max warming temps as well as the average too.

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

Average warming temp max = -17.81C

Unfortunately today the warming signal has reduced slightly with that average warming temp max now at -17.81C compared with yesterday's -16.13C. Not the trend we would want to see if we want to get a SSW.

However picked out the 3 warmest charts showing something more significant just for some eye candy.

Edited December 22, 2021 by SqueakheartLW

[Don]

2 hours ago, SqueakheartLW said:

Unfortunately today the warming signal has reduced slightly with that average warming temp max now at -17.81C compared with yesterday's -16.13C. Not the trend we would want to see if we want to get a SSW.

What with the collapse of the potential Christmas cold spell, this is another kick in the teeth for coldies!  I give up (well not quite but wanted some positive news today)!!

Edited December 22, 2021 by Don

[joggs]

8 minutes ago, Don said:

What with the collapse of the potential Christmas cold spell, this is another kick in the teeth for coldies!  I give up!!

You couldn't make it up lol.

[Don]

5 minutes ago, joggs said:

You couldn't make it up lol.

No you couldn't!  However, too early to give up on winter at this stage (albeit tempting!).  With climate change at play though, these issues for cold will get progressively worse!

Edited December 22, 2021 by Don

[Catacol]

So much depends on the tools we use - and how the data is put forward. I still like these Berlin charts. Wave 2 intensifying a bit more

and flux picking up too

From small acorns.....?

[SqueakheartLW]

Time for my daily stratospheric update and as the cold chase on the models has come to nothing (AS USUAL) then I will focus more on the potential SSW that is showing up on the GFS. As with the previous updates I am focusing on the 06z for these but today I have decided to include the GEM 00z into the mix for comparison. The GEM Op run only goes to 240 hours so the potential warming is out of its range so isn't included in the GEM figures.

Today's GFS 06z max 10hpa warming figures as well as the new GEM 00z figures too

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

Average Warming Max GFS = -17.94C                Average Warming Max GEM = -22.86C

As you can see both models are going for a warming of some degree early next year with the GFS currently more keen for this warming compared with the GEM

We have no previous figure to compare to with the GEM today as it is the debut for this model in my updates but bad news again for the GFS as it has yet again reduced the warming max temperature again from -17.81C yesterday to -17.94C today.

Yet again another step in the wrong direction if we as it now looks like are resorting to pinning our hopes on a SSW to deliver the goods.

Best charts today from both GFS and GEM

GFS

GEM

[Don]

11 minutes ago, SqueakheartLW said:

We have no previous figure to compare to with the GEM today as it is the debut for this model in my updates but bad news again for the GFS as it has yet again reduced the warming max temperature again from -17.81C yesterday to -17.94C today.

Yet again another step in the wrong direction if we as it now looks like are resorting to pinning our hopes on a SSW to deliver the goods.

Thanks SqueakheartLW

I'm hoping we might get some positive news soon!  Perhaps the Berlin charts will give us more hope?

[Catacol]

OK - with all the ups and downs in other model data, this is much better. Small acorn now with a shoot of green....

[feb1991blizzard]

2 hours ago, Catacol said:

OK - with all the ups and downs in other model data, this is much better. Small acorn now with a shoot of green....

blimey thats a stonker. i usually half the number of a w1 for a w2 and 2500 for a wave 1 is very good so.............

Edited December 23, 2021 by feb1991blizzard

[stodge]

6 hours ago, Catacol said:

OK - with all the ups and downs in other model data, this is much better. Small acorn now with a shoot of green....

Do you think our possible cold spell was scuppered by Wave 1 activity which displaced too much energy back to the Canadian side?

[Catacol]

17 minutes ago, stodge said:

Do you think our possible cold spell was scuppered by Wave 1 activity which displaced too much energy back to the Canadian side?

No - I think it was scuppered by one of the fastest retrogressions of a block I can remember seeing. We were supposed to be in an Omega round about now - but in fact the block is already in Greenland and it is moving double quick out west. Why did this happen? I genuinely have no idea. I love watching winter weather and have done it quite a long time. Blocks are slow moving. Blocks defy the models by slowing the progress of change. Whatever is going on in the atmosphere at the moment - this one broke all the observational rules. It actually formed and moved before the pacific jet extension I flagged a while back even arrived. And the jet has now adopted a much flatter profile. 

Time to move on from it - perhaps return to analyse the hindcast another time. ECM and the MetO are in stark opposition now for New Year which is odd. This winter has an odd feel about in general! But my eyes now firmly turn to chances of an SSW. However.....the atmosphere is firmly holding to a Nino style forcing and what this means for our statistically good chances of an SSW in a Nina/eQBO year I dont know. Only 1995/96 and 2011/12 were Ninas with eQBO that didnt produce a SSW and I dont know what their Pacific profile was. But anyway....we know a SSW with a downwelling response can force dramatic impacts on the troposphere. Fingers crossed for a 2018 style product.

The wave 2 forecast on ECM today is a good start. 

[stodge]

11 minutes ago, Catacol said:

No - I think it was scuppered by one of the fastest retrogressions of a block I can remember seeing. We were supposed to be in an Omega round about now - but in fact the block is already in Greenland and it is moving double quick out west. Why did this happen? I genuinely have no idea. I love watching winter weather and have done it quite a long time. Blocks are slow moving. Blocks defy the models by slowing the progress of change. Whatever is going on in the atmosphere at the moment - this one broke all the observational rules. It actually formed and moved before the pacific jet extension I flagged a while back even arrived. And the jet has now adopted a much flatter profile. 

That's an interesting point - my recollection of the BTFE from 2018 was how quick the HP moved west across the northern hemisphere. We just seem unable to hold on to an east-based negative NAO currently - it quickly heads west. 

Looking at the 12Z GFS from December 14th and seeing the T+216 is enlightening - the HP was even then not retrogressing but moving into Scandinavia after flirting with Greenland.

As you say, plenty to chew over in the days ahead.

[knocker]

 

[Catacol]

5 minutes ago, stodge said:

That's an interesting point - my recollection of the BTFE from 2018 was how quick the HP moved west across the northern hemisphere. We just seem unable to hold on to an east-based negative NAO currently - it quickly heads west. 

Looking at the 12Z GFS from December 14th and seeing the T+216 is enlightening - the HP was even then not retrogressing but moving into Scandinavia after flirting with Greenland.

As you say, plenty to chew over in the days ahead.

Ah.....well Feb/Mar 2018 produced the most incredible synoptics I have ever seen. The whole pattern completely reversed - everything moved east to west in response to complete stratospheric meltdown and a vortex shard that spun down over Asia and headed west to Europe. Storm Emma would have so much better just a month earlier!

[feb1991blizzard]

@Catacol Are you concerned by Knocker's post above?, i must admit you usually see some members showing an SSW at any given point, at this point of the year, that is probably the strongest signal against a Jan SSW i have ever seen.

[Don]

9 minutes ago, feb1991blizzard said:

@Catacol Are you concerned by Knocker's post above?, i must admit you usually see some members showing an SSW at any given point, at this point of the year, that is probably the strongest signal against a Jan SSW i have ever seen.

I certainly am.  I may get shot down for saying this, but I'm getting a horrible feeling in my stomach about this winter now!

[summer blizzard]

Statistically speaking SSW's are most common the deeper into Q1 one goes anyway so I'm not overly concerned in terms of a meaningful attempt given that the tropics are active (I e. We do have wave driving supportive of an attempt).

My primary concern is that the atmosphere is strongly coupled to a La Nina favouring a stronger vortex late season. I can forsee a situation like winter 2012 whereby we get an attempt, less than a month of settled/cold weather and then the pattern reverts to a +AO.

[SqueakheartLW]

Time again for my daily SSW update in the potential for the GFS 06z and GEM 00z showing up in the models.

Yesterday was a disappointment all round with the loss of a cold signal and a further reduction of the SSW signal from GFS.

How does today compare then?

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

Average Warming Max GFS = -17.81C                                Average Warming Max GEM = -24.57C

Mixed news here in the fact that the GFS has slightly strengthened the warming signal once again with an average max warming temperature of -17.81C today compared with -17.94C yesterday.

The GEM has however gone the other way. It was already less keen with the warming anyway but today's average warming max of -24.57C is less warm than the -22.86C from yesterday so a step in the wrong direction.

Best Charts from both the GFS 06z and the GEM 00z

GFS

GEM

[SqueakheartLW]

Is there any festive cheer showing up at 10hpa today in terms of warming potential. Time for me to go over the GFS 06z and the GEM 00z as normal

Temp    Member GFS                                                                         Temp    Member GEM                    
-36                                                                                                         -36         02
-32                                                                                                         -32         12,14,19
-28                                                                                                         -28         07,09,18,20
-24         14,15                                                                                      -24         Ct,03,04,06,08,13,15,17
-20         04,08,09,10,11,13,20,22,25,27,30                                     -20          01,05,10,11,16
-16         Op,Ct,01,02,03,05,06,07,12,16,17,18,19,23,24,28,29    -16    
-12         21,26                                                                                      -12                                                     

Average Warming Max GFS = -18.19C                                            Average Warming Max GEM = -25.52C

Although bad news for both models as their average warming max values have got less warm for both models with a drop from -17.81C to -18.19C for the GFS as well as -24.57C to -25.52C for GEM the GFS at least seems to be coming towards a more consistent values for the warming max with -16C the current favourite.

Best Charts From Both GFS and GEM

GFS

GEM

Member 11 on the GEM is of interest. Although a modest warming showing up with a max of -20C it is the result of this warming that is of most interest

The result is clear to see with an attempt to split the vortex and with signs of another warming appearing at this stage near Canada then that could be the final blow that does split the vortex.

I know it's only one member of one of the models but it was good to see this appearing today.

[Pixel]

remaining there as modelled earlier...

outlier?

Edited December 26, 2021 by Pixel

[SqueakheartLW]

Looks like the warming is now counting down the hours and with a definite signal now showing it would seem the early 2022 warming looks nailed on. The question now is how warm it will be and what the result will be on the vortex.

As the vortex has generally run above average recently then the most likely outcome of the warming is just a weakening, most likely back to near average again or if we are lucky, below average.

GFS is still more keen than GEM for this warming and it would appear -16C is going to be the expected peak of the warming with today's average -16.58C on the GFS 06z and ensembles today which is a step in the right direction compared with -18.19C yesterday.

GEM is still less keen for the warming but it has also upgraded the signal too, going from -25.52C yesterday to -23.09C today.

Best GFS Member Today - Member 9

We see a peak here of -16C which is basically bang on the average for today's GFS 06z update but what has made me single out member 9 is what happens later on in the run.

This initial burst of warming subsides somewhat but look what happens further on

Another warming is hinted at here and Member 9 shows this up the most but there are other GFS members that hint at a possible 2nd warming after the initial one.

Best GEM Member - Member 5

No 2nd warming showing up on GEM but Member 5 is simply the best one on the GEM

ECM

The warming is even showing up on ECM at 10hpa now

Just for fun. The very highest levels of the strat

1hpa

At day 9 we almost manage to split the 1hpa vortex

2hpa

Same situation on day 9 at 2hpa

3hpa

Almost there but less visible here

Wave activity

This is insane for wave 2 activity but we could really do with some wave 1 too to help us out more.

[JeffC]

There is a slight warming already showing at 10hpa over eastern Russia

[bluearmy]

Ec at day 10 this morning is trying to split the spv from the bottom up ( no doubt from the trop pacific ridge ) 

gfs is not with the spv/tpv same locale top to bottom on the 00z run (as was the case yesterday)

something to watch …..

[mushymanrob]

21 hours ago, SqueakheartLW said:

Looks like the warming is now counting down the hours and with a definite signal now showing it would seem the early 2022 warming looks nailed on. The question now is how warm it will be and what the result will be on the vortex.

As the vortex has generally run above average recently then the most likely outcome of the warming is just a weakening, most likely back to near average again or if we are lucky, below average.

GFS is still more keen than GEM for this warming and it would appear -16C is going to be the expected peak of the warming with today's average -16.58C on the GFS 06z and ensembles today which is a step in the right direction compared with -18.19C yesterday.

GEM is still less keen for the warming but it has also upgraded the signal too, going from -25.52C yesterday to -23.09C today.

Best GFS Member Today - Member 9

We see a peak here of -16C which is basically bang on the average for today's GFS 06z update but what has made me single out member 9 is what happens later on in the run.

This initial burst of warming subsides somewhat but look what happens further on

Another warming is hinted at here and Member 9 shows this up the most but there are other GFS members that hint at a possible 2nd warming after the initial one.

Best GEM Member - Member 5

No 2nd warming showing up on GEM but Member 5 is simply the best one on the GEM

ECM

The warming is even showing up on ECM at 10hpa now

Just for fun. The very highest levels of the strat

1hpa

At day 9 we almost manage to split the 1hpa vortex

2hpa

Same situation on day 9 at 2hpa

3hpa

Almost there but less visible here

Wave activity

This is insane for wave 2 activity but we could really do with some wave 1 too to help us out more.

hi
whats the difference between wave 1 and wave 2 please?