Stratosphere and Polar Vortex Watch 2020

[Vikos]

Just a tripol, nothin' special...

[DOdo]

3 hours ago, bluearmy said:

There was a short dip to mid twenties zonal flow around dec 15 but there is no evidence that this had any influence on the lower strat and into the trop.  

Thank you for your reply Bluearmy

[Anthony Burden]

GFS GEM ICON all at 168 hrs showing this north easterly flow just into reliable time frame 

but more so with 3 models all with the relatively the same Synoptics.UKMO showing northern 

blocking at 144 hrs .Continental air stream looking to take over back to winter with more of a 

Very cold outlook possible.

[Vikos]

After strong incorrect forecasts that were too warm last year the ECMWF-ENSO forecasts from January 1, 2021 initially show a continuation of the La Niña conditions in the equatorial Pacific in the relevant Nino area 3.4 with SSTA of -0.5K and colder. The deviations are supposed to reach the neutral range in springtime 2021, but there is already a slight “kink” downwards in June / July 2021 even in the “warm computers” from ECMWF

[bluearmy]

Just a note that the gfs op 12z strat between 10 and 50hpa looks like the 12z ec op strat 

it’s not unreasonable to think that ec would carry on as per the gfs run, especially higher up 

[SqueakheartLW]

1 hour ago, Vikos said:

After strong incorrect forecasts that were too warm last year the ECMWF-ENSO forecasts from January 1, 2021 initially show a continuation of the La Niña conditions in the equatorial Pacific in the relevant Nino area 3.4 with SSTA of -0.5K and colder. The deviations are supposed to reach the neutral range in springtime 2021, but there is already a slight “kink” downwards in June / July 2021 even in the “warm computers” from ECMWF

Isn't this ENSO related. There's an ENSO thread for this

[Vikos]

22 minutes ago, SqueakheartLW said:

Isn't this ENSO related. There's an ENSO thread for this

Well, didn't know that. Call an Admin to remove it or replace it

[Allseasons-Si]

The gfs 18z goes for a split in the EXT...

[bluearmy]

Day 10 ec op at 50 hpa leaves a little piece of the spv over se England ....... 

the ridging of the Atlantic into greeny  in the 5/10 day period looks to be supported in the upper strat and is not one persistent feature but it waxes and wanes as the remnants of the spv left in the Atlantic sector are drawn back to the Asian parent vortex. Even at day 10 there is still a daughter vortex in the s Davis straight area (30+50hpa)

 

[sebastiaan1973]

Downwelling all the way to day 10. Vortex replaced to NW-Russia.

[WINTRY WALES]

So.....either of the above two posts good for cold chances in the uk ??

[northwestsnow]

34 minutes ago, WINTRY WALES said:

So.....either of the above two posts good for cold chances in the uk ??

Yes.

[bluearmy]

58 minutes ago, sebastiaan1973 said:

Downwelling all the way to day 10. Vortex replaced to NW-Russia.

We could do with losing the small positive bubble at 60. For the next 10 days at least we keep some mobility in the Atlantic sector(unclear at what level) ....if we can suppress the southern arm then that’s not a problem 

 

Edited January 9, 2021 by bluearmy

[Guest]

Watching the Met office thoughts at the end to their 10 day update they mention how La Nina could try and counteract against any potential cold from the SSW during second half of winter, So we need blocking to happen quite quickly, because you would think once she fires up and we haven't got blocking in place it could be a struggle! Are there any signs of La Nina influences having effect yet. Would be interesting to know how SSWs have fared  in past La Nina winters regarding UK cold percentage wise. 

 

 

 

 

 

 

[Cymro]

4 minutes ago, Snowmut said:

Watching the Met office thoughts at the end to their 10 day update they mention how La Nina could try and counteract against any potential cold from the SSW during second half of winter, So we need blocking to happen quite quickly, because you would think once she fires up and we haven't got blocking in place it could be a struggle! Are there any signs of La Nina influences having effect yet. Would be interesting to know how SSWs have fared  in past La Nina winters regarding UK cold percentage wise. 

 

 

 

 

 

 

My understanding was that La Niña was projected to go into a weak rather than strong state so took from that that it's influence would gradually weaken??? 

[SqueakheartLW]

GFS + Parallel

GFS 00z Parallel going for 4 warming in a row here with the initial 3rd warming peaking at -4 at +240 hours away. This is followed by 3 successive warmings all merged into one to make 4 warmings in total with peaks at -12 at +288 hours, another -12 at 324 hours and finally -16 at 384 hours away. Look at how much damage that does to the vortex by the end of the run

How does the operational GFS 00z compare to the parallel. We get the 3rd warming underway which peaks at -12 at +228 hours away. This cools down a bit before another warming which peaks at -16 at +330 hours away. This warming cools slightly but persists at around -20 right till the end of the run when by this stage the vortex is in quite bad shape

Below we have a selection of the most destroyed vortexes from the 00z GFS Runs

14 of 33 options showing a badly beaten up vortex and several runs end with another major warming too. Surely not 4 warmings within the same month

GEFS Legacy

GEFS Legacy still sees the 3rd warming but is less keen to do damage to the vortex afterwards

JMA

JMA has signs of this 3rd warming but unlike other models it also has one appearing on the Atlantic side too

GEM

3rd warming now more clearly visible on the GEM

ECM

3rd warming now more evident with the ECM at day 10

NAVGEM

NAVGEM still not seeing the 3rd warming but it does only go to 180 hours away and it is only starting to show up on the 240 hours away models anyway

NASA

A bit of a 3rd warming showing up at 240 hours but far less warm than on some other models

CMA

CMA already has a significant warming underway before 240 hours and there isn't a lot left of the vortex

FIM

There is a small warming showing up above Siberia on the FIM by 240 hours. Maybe FIM now seeing the 3rd warming too

SUMMARY

Each of the featured models and whether they see the 3rd warming or not

GFS                   Yes
GEFS Legacy    Yes
JMA                   Yes
GEM                  Yes
ECM                   Yes
NAVGEM           No
NASA                 Yes
CMA                   Yes
FIM                     Yes

A increase from 6 of 9 models yesterday to 8 of 9 today is a big step forwards. Now looking even more certain that we are going to get this 3rd warming

[northwestsnow]

Just a quickie...

BBC monthly talking about a strengthening vortex later this month...

[ScottSnow]

14 minutes ago, northwestsnow said:

Just a quickie...

BBC monthly talking about a strengthening vortex later this month...

Strengthening Atlantic is what they are saying but the Meto is different in their outlook.

[mountain shadow]

18 minutes ago, northwestsnow said:

Just a quickie...

BBC monthly talking about a strengthening vortex later this month...

That's fine as long as it goes under the wedges. Copious snowfall. 

[mb018538]

20 minutes ago, northwestsnow said:

Just a quickie...

BBC monthly talking about a strengthening vortex later this month...

Bit misleading from the BBC. It’ll strengthen no doubt, but if it only strengthens to say 10-15m/s as forecast then it’s still a long way below normal and nothing like a usual winter season.

[bluearmy]

1 hour ago, northwestsnow said:

Just a quickie...

BBC monthly talking about a strengthening vortex later this month...

Well it couldn’t really get any weaker ????

what goes up must come down and vice versa .....

[Windysun1]

1 hour ago, SqueakheartLW said:

GFS + Parallel

GFS 00z Parallel going for 4 warming in a row here with the initial 3rd warming peaking at -4 at +240 hours away. This is followed by 3 successive warmings all merged into one to make 4 warmings in total with peaks at -12 at +288 hours, another -12 at 324 hours and finally -16 at 384 hours away. Look at how much damage that does to the vortex by the end of the run

How does the operational GFS 00z compare to the parallel. We get the 3rd warming underway which peaks at -12 at +228 hours away. This cools down a bit before another warming which peaks at -16 at +330 hours away. This warming cools slightly but persists at around -20 right till the end of the run when by this stage the vortex is in quite bad shape

Below we have a selection of the most destroyed vortexes from the 00z GFS Runs

14 of 33 options showing a badly beaten up vortex and several runs end with another major warming too. Surely not 4 warmings within the same month

GEFS Legacy

GEFS Legacy still sees the 3rd warming but is less keen to do damage to the vortex afterwards

JMA

JMA has signs of this 3rd warming but unlike other models it also has one appearing on the Atlantic side too

GEM

3rd warming now more clearly visible on the GEM

ECM

3rd warming now more evident with the ECM at day 10

NAVGEM

NAVGEM still not seeing the 3rd warming but it does only go to 180 hours away and it is only starting to show up on the 240 hours away models anyway

NASA

A bit of a 3rd warming showing up at 240 hours but far less warm than on some other models

CMA

CMA already has a significant warming underway before 240 hours and there isn't a lot left of the vortex

FIM

There is a small warming showing up above Siberia on the FIM by 240 hours. Maybe FIM now seeing the 3rd warming too

SUMMARY

Each of the featured models and whether they see the 3rd warming or not

GFS                   Yes
GEFS Legacy    Yes
JMA                   Yes
GEM                  Yes
ECM                   Yes
NAVGEM           No
NASA                 Yes
CMA                   Yes
FIM                     Yes

A increase from 6 of 9 models yesterday to 8 of 9 today is a big step forwards. Now looking even more certain that we are going to get this 3rd warming

Hi Squeakheart, you do excellant research and love your posts. 

You say its a big step forward that there is going to be a warming. I have no doubt you are right, but how potentially how does this effect the uk? Does it all depend on where the PV ends up or  chunks of the pv ending up if it gets split up?

[northwestsnow]

11 minutes ago, bluearmy said:

Well it couldn’t really get any weaker ????

what goes up must come down and vice versa .....

No doubt.

The inference i suspect was a ref to a flatter Atlantic ...born out by the very underwhelming text.

[SqueakheartLW]

Plenty of weak or very weak vortex options by 384 hours on the 06z GFS and parallel runs. I have picked out the ones that look weakest

Not only this there are many charts now showing a potential 4th warming event at the later stages of the runs

24 of 33 GFS 06z runs on board with a possible 4th warming. I don't know what the record is for maximum number of stratospheric warmings in a month but 4 must be a record

 

[Vikos]

/off-topic

I appriciate efforts in posting much info in one post, but could it be possible not to post "hundreds" of charts in one post? It firstly slows down the thread and second kills users on smartphones (useablilty/scrolling and data-traffic).