Stratosphere and Polar Vortex Watch 2020

[blizzard81]

2 hours ago, LRD said:

Don't get me wrong, the science is important and should always be pursued and improved so our understanding improves. However, the thing is there is ALWAYS something that results in us not getting a cold winter lately (since 2013-14 anyway and most years from 1987/88-2007/08).

WQBO too strong; ENSO is either too warm or cold or central or east or west; IOD is too, er, whatever that does, MoJO, Brewers Droop Circulation, a warm Pacific Ocean around Alaska, me wearing tight underwear, SSTs. The list is endless

Whatever it is there is always something to scupper a cold winter season for the UK and parts of Europe due to too much stratospheric/tropospheric activity at the North Pole. Makes you think there might be a greater, more broad thing happening to our climate. I wonder what that could be... 

Ha ha ha that is such a funny post....... In a good way. So true as well. 

[sebastiaan1973]

3 hours ago, SqueakheartLW said:

Good news for EQBO fans. NASA site has updated the phase plot

Now that looks more promising if you want the EQBO to try and make a comeback

The bad news is the latest QBO figure for October 2020 which has strengthened the WQBO further

                   JAN          FEB          MAR         APR         MAY         JUN          JUL            AUG          SEP            OCT

2020          -2.51       -3.20        -4.36        -5.03        -4.86        -2.78        +0.34        +4.78        +7.95        +10.80

Up to double figures and very much now in strong WQBO territory now. Anything at +10 or more on my scale is a strong WQBO. Even worse news for winter now

At least the stratospheric zonal wind forecast clearly shows the EQBO starting to make its descent in the next 10 days

Latest chart                                                10 days forecast

The question is, will it increase a lot? I don't think so.

[topo]

Arctic is the fastest warming place on the planet due to climate change.

That leads to ice forming very late compared to the past.

That also leads to an open sea where low pressure is easiest to form and winter is coming more and more late at the Northern Hemisphere. So late that December is almost no winter anymore, last December below normal was 10 years ago. 

Think about it, it is like having November instead of December and December instead of January... Then February and March is what is remaining from the Winter...

I am really curious about winters in 30 years from now for example with arctic almost entirely ice free in the summers..

[Don]

15 minutes ago, blizzard81 said:

Ha ha ha that is such a funny post....... In a good way. So true as well. 

Yes, it's getting more and more difficult to get a cold winter now.  As I said in the tweets thread, I think we now have a good idea where this coming one is going....

[Don]

3 minutes ago, topo said:

I am really curious about winters in 30 years from now for example with arctic almost entirely ice free in the summers..

I seriously dread to think! 

[DavidS]

This is the S & PV thread right?

[masheeuk]

3 hours ago, DavidS said:

This is the S & PV thread right?

THank you I was beginning to wonder myself!!!!!

[SqueakheartLW]

I wonder if the CFS is onto something here

After this record breaking reversal prediction

Then to show 2 more runs going into reversal now in December too

All of the associated bias corrected runs linked to these also go into reversal too

With all of the other factors seemingly going wrong yet again for a colder UK winter it would seem we are going to have to place all of our hopes on a SSW yet again to deliver the goods

[Methuselah]

My personal thoughts about the CFS remain exactly as they were, back in 2013 -- it's next to useless... So I don't ask myself what it's on to, but just, what it's on!

[Allseasons-Si]

 

[northwestsnow]

Yep saw that tweet...

Hmmmmmmm.

[Catacol]

5 hours ago, SqueakheartLW said:

I wonder if the CFS is onto something here

After this record breaking reversal prediction

Then to show 2 more runs going into reversal now in December too

All of the associated bias corrected runs linked to these also go into reversal too

With all of the other factors seemingly going wrong yet again for a colder UK winter it would seem we are going to have to place all of our hopes on a SSW yet again to deliver the goods

Tropospheric pre cursors for wave 2 forcing remain good. Lag times often up to 4 weeks so some of this data fits. While people gnash their teeth over on the model thread about warm Euro or even better ScEuro blocks I'm rubbing my hands in glee. I dont think cold weather in this country just "happens" - we know it is rare. It needs various drivers to align and then a bit of luck thrown in. Nina for early season ridging followed by the potential for a wave 2 driven SSW remains our greatest opportunity for sustained or memorable cold weather this season. Long live the ScEuro block through much of November if it helps promote this kind of vortex disruption. The real action is mid December to end of February (usually) and that's where we want things to kick in!!

[damianslaw]

6 hours ago, Catacol said:

Tropospheric pre cursors for wave 2 forcing remain good. Lag times often up to 4 weeks so some of this data fits. While people gnash their teeth over on the model thread about warm Euro or even better ScEuro blocks I'm rubbing my hands in glee. I dont think cold weather in this country just "happens" - we know it is rare. It needs various drivers to align and then a bit of luck thrown in. Nina for early season ridging followed by the potential for a wave 2 driven SSW remains our greatest opportunity for sustained or memorable cold weather this season. Long live the ScEuro block through much of November if it helps promote this kind of vortex disruption. The real action is mid December to end of February (usually) and that's where we want things to kick in!!

Should the La Nina forcing not be resulting a mid atlantic high, rather than a sceuro high as others call it - or is to do with the MJO activity moving through the Tropics promoting ridging to our east instead.

Once this does its job, should we then expect the ridge to transfer through the UK and to our west by the end of the month, correction back to a La Nina state.

A plausible scenario is for the sceuro high to sink, jet riding in on typical SW-NE alignment with azores high then building in behind, but then ridging west and we have a trigger to a colder northerly block by month's end. This would result in a very quiet mild November in the main, but perhaps not a bad thing if it means colder for December.

[Catacol]

24 minutes ago, damianslaw said:

Should the La Nina forcing not be resulting a mid atlantic high, rather than a sceuro high as others call it - or is to do with the MJO activity moving through the Tropics promoting ridging to our east instead.

Once this does its job, should we then expect the ridge to transfer through the UK and to our west by the end of the month, correction back to a La Nina state.

A plausible scenario is for the sceuro high to sink, jet riding in on typical SW-NE alignment with azores high then building in behind, but then ridging west and we have a trigger to a colder northerly block by month's end. This would result in a very quiet mild November in the main, but perhaps not a bad thing if it means colder for December.

Yes. The passage of the MJO and parallel spike in AAM has interfered with the Nina base state. It should begin to return to a mid atlantic ridge-style forcing in the second half of the month. That's if it goes to "plan" - maybe our climate is such now that the predictable is becoming more unpredictable....

[booferking]

1 hour ago, damianslaw said:

Should the La Nina forcing not be resulting a mid atlantic high, rather than a sceuro high as others call it - or is to do with the MJO activity moving through the Tropics promoting ridging to our east instead.

Once this does its job, should we then expect the ridge to transfer through the UK and to our west by the end of the month, correction back to a La Nina state.

A plausible scenario is for the sceuro high to sink, jet riding in on typical SW-NE alignment with azores high then building in behind, but then ridging west and we have a trigger to a colder northerly block by month's end. This would result in a very quiet mild November in the main, but perhaps not a bad thing if it means colder for December.

Something like this 18z just hope nina state dont get overridden again end of the month.

[mb018538]

Current forecasts still show a much stronger than normal PV heading into December.

Slightly further ahead, there is a little interest with some CFS members going for a reversal into the new year. Even one of the bias corrected runs goes for it too! Should probably also state that some bias corrected runs are record strong at the same time too....but that's not fun is it! SSW?

[SqueakheartLW]

1 hour ago, mb018538 said:

Current forecasts still show a much stronger than normal PV heading into December.

Slightly further ahead, there is a little interest with some CFS members going for a reversal into the new year. Even one of the bias corrected runs goes for it too! Should probably also state that some bias corrected runs are record strong at the same time too....but that's not fun is it! SSW?

When looking at the GFS forecast in particular it is almost a mirror image of last year.

In 2019 at this point the vortex got weaker than average as we headed into December before the polar vortex of doom got going later in December.

If we go strong early on in December and then do the opposite of last winter we should see the vortex weaken or collapse completely later in December then remain generally weaker than average after that

Then again there are examples of years with above average zonal winds at 10hpa going along with colder than average winters

[Methuselah]

On 04/11/2020 at 15:04, DavidS said:

This is the S & PV thread right?

Going by the amount of physical/emotional/mental torture it contains, I was starting to see it as the S&M thread!

[wellington boot]

On 05/11/2020 at 09:45, SqueakheartLW said:

I wonder if the CFS is onto something here

After this record breaking reversal prediction

Then to show 2 more runs going into reversal now in December too

All of the associated bias corrected runs linked to these also go into reversal too

With all of the other factors seemingly going wrong yet again for a colder UK winter it would seem we are going to have to place all of our hopes on a SSW yet again to deliver the goods

I am a bit perplexed by the focus on these CFS runs. It seems there are enough members to cover the entire space between record breaking weak and record breaking strong vortex, so in what sense do they actually indicate anything useful? In any case, most members, certainly after correction, seem to forecast positive anomalies...

[wellington boot]

On 04/11/2020 at 10:57, SqueakheartLW said:

Good news for EQBO fans. NASA site has updated the phase plot

Now that looks more promising if you want the EQBO to try and make a comeback

The bad news is the latest QBO figure for October 2020 which has strengthened the WQBO further

                   JAN          FEB          MAR         APR         MAY         JUN          JUL            AUG          SEP            OCT

2020          -2.51       -3.20        -4.36        -5.03        -4.86        -2.78        +0.34        +4.78        +7.95        +10.80

Up to double figures and very much now in strong WQBO territory now. Anything at +10 or more on my scale is a strong WQBO. Even worse news for winter now

At least the stratospheric zonal wind forecast clearly shows the EQBO starting to make its descent in the next 10 days

Latest chart                                                10 days forecast

Also can someone please explain to me how the QBO can be in both in an easterly and westerly phase at the same time...? Have come across this clash before without following up - is it that different sources are focusing on different atmospheric levels?

[summer blizzard]

3 hours ago, wellington boot said:

Also can someone please explain to me how the QBO can be in both in an easterly and westerly phase at the same time...? Have come across this clash before without following up - is it that different sources are focusing on different atmospheric levels?

It means it's weakening in theory.

The standardised value was +1.24.

[frederiksen90]

What an interesting change u vortex according to EC-ensemble.  A weakening on the way:

https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-2040/57/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-T8V3Hu.png

[Eskimo]

13 minutes ago, frederiksen90 said:

What an interesting change u vortex according to EC-ensemble.  A weakening on the way:

https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-2040/57/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-T8V3Hu.png

A weakening compared to where we are at, but huge spread and that spread is averaging around the long-term average, so not seeing much excitement just yet. 

Edited November 12, 2020 by PerfectStorm

[frederiksen90]

Men en svækkelse i forhold til mandagens ensemble-kørsel. Ret stor ændring: https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-0600/d7/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-7oWzWZ.png Fra noget, der udviklede sig til en stabil stærk PV, er det nu en større ændring. Måske en tendens mod en stor svækkelse, som bliver endnu tydeligere i næste kørsel på mandag?

[Griff]

5 minutes ago, frederiksen90 said:

Men en svækkelse i forhold til mandagens ensemble-kørsel. Ret stor ændring: https://stream.ecmwf.int/data/gorax-green-001/data/scratch/20201112-0600/d7/ps2png-gorax-green-001-6fe5cac1a363ec1525f54343b6cc9fd8-7oWzWZ.png Fra noget, der udviklede sig til en stabil stærk PV, er det nu en større ændring. Måske en tendens mod en stor svækkelse, som bliver endnu tydeligere i næste kørsel på mandag?

Google translate to the rescue, but I agree quite different charts