Stratosphere and Polar Vortex Watch 2020

[SqueakheartLW]

That's one big disconnect showing up there on this chart. Those red positive raging stratospheric vortex anomalies against those blue weaker ones in the troposphere.

[damianslaw]

6 hours ago, Catacol said:

Yes - I think the 1995/96 analogue is our best analogue for chances of cold weather in the later stages of this winter. Nina continues to edge east, and there is much less evidence of a zonal February when Nina is east based. We will see. However one thing is for sure - the strong vortex is a substantial problem when looking for high latitude blocking, regardless of NAM charts illustrating a less connected state than might be the case.

Second half of winter 95-96 I think saw a strong PV but it had no impact. There was a long blocked spell and precipitation often of snow with some rain at times mid Feb. It was a great winter for easterlies.

[Catacol]

5 hours ago, damianslaw said:

Second half of winter 95-96 I think saw a strong PV but it had no impact. There was a long blocked spell and precipitation often of snow with some rain at times mid Feb. It was a great winter for easterlies.

The year of my second best ever snow week while living in England. March 2018 sneaks top spot, but Feb 96 in the south for me was awesome. Forecast of rain. Opened my curtains and my car was buried up over the number plate….and the snow stayed and repeated all week. Never forget it….and all from a very marginal slider setup.

[Don]

6 hours ago, SqueakheartLW said:

That's one big disconnect showing up there on this chart. Those red positive raging stratospheric vortex anomalies against those blue weaker ones in the troposphere.

We will just have to hope it remains disconnected then, otherwise the likelihood of any sustained cold this winter is off the table?

1 hour ago, Catacol said:

The year of my second best ever snow week while living in England. March 2018 sneaks top spot, but Feb 96 in the south for me was awesome. Forecast of rain. Opened my curtains and my car was buried up over the number plate….and the snow stayed and repeated all week. Never forget it….and all from a very marginal slider setup.

Just out of interest, where in the south were you as I saw very little snow in February 1996?

[damianslaw]

2 hours ago, Don said:

We will just have to hope it remains disconnected then, otherwise the likelihood of any sustained cold this winter is off the table?

Just out of interest, where in the south were you as I saw very little snow in February 1996?

Possibly from the NE flow around 18th-20th of the month from memory. Some eastern parts received heavy snow showers. 

 

[Mike Poole]

23 hours ago, Don said:

We will just have to hope it remains disconnected then, otherwise the likelihood of any sustained cold this winter is off the table?

Just out of interest, where in the south were you as I saw very little snow in February 1996?

Yes, Don, from where we are now that’s exactly what we must hope.  Since my joining netweather, the strat has always been a crucial part of the discussion around UK winter prospects, except for this year, where it just roars away overhead, with very limited effect on our weather down here:

On it goes…

But if it did couple now properly with the trop, there’s no time for the precursor mechanisms to a SSW to happen in time for any hypothetical SSW to affect winter or even early spring in terms of UK cold.  It has been interesting to watch something different this year, but my lack of posts in here is just because there is nothing of interest on the cards re the strat and never has been this winter.

[Don]

42 minutes ago, Mike Poole said:

Yes, Don, from where we are now that’s exactly what we must hope.  Since my joining netweather, the strat has always been a crucial part of the discussion around UK winter prospects, except for this year, where it just roars away overhead, with very limited effect on our weather down here

Just a shame we haven't benefitted really!

[bluearmy]

well we haven’t seen a chart like this for months - yes I know it’s an op day 16 

[Frostbite1980]

2 hours ago, bluearmy said:

well we haven’t seen a chart like this for months - yes I know it’s an op day 16 

Sorry Blue, what is this showing? 

[summer blizzard]

Could be wrong but it looks like positive heat transport albeit mainly to the mid latitudes. 

[bluearmy]

On 15/01/2022 at 10:56, Frostbite1980 said:

Sorry Blue, what is this showing? 

Sorry - missed that

 a large slowdown in zonal flow across the strat n of 50/60N. 

But it was an erroneous run so can be ignored 

[Peter H]

On 11/01/2022 at 13:43, damianslaw said:

Second half of winter 95-96 I think saw a strong PV but it had no impact. There was a long blocked spell and precipitation often of snow with some rain at times mid Feb. It was a great winter for easterlies.

We had a white Christmas that season here in Northern Ireland, at least over east Antrim and north Down. 
 

I remember taking the dog for a walk on Christmas Eve 1995 and it was snowing, which was very festive indeed. 

[SqueakheartLW]

Something we all know by now is how we have a strong stratospheric vortex this season that is showing no signs of slowing down anytime soon but how strong has it really been and can we really compare to a polar vortex of doom.

Today I present you the 60N zonal wind speeds and anomalies from average for 18th January 2022 and all other years on the same date and show how we compare with the average and all those years.

I was quite surprised to see our 47.00 m/s speed wasn't even in the top 10 for zonal wind speeds for this date and many years had much faster zonal winds and those top 3 figures look frightening to say the least.

However one thing I have seen from CET data is how 1988/1989 winter was mild, no surprise to see a fast zonal wind there. 2004/2005 had also been mild up to this point too and 2015/2016 certainly had been.

We are certainly well ahead of last year when we were in a slight reversal on this day at -3.20 m/s.

Rolling mean zonal wind speeds

I shall present you another set of data which shows the average zonal wind speeds from 1st November up to 18th January this year as well as all others on the record.

Again I was quite surprised to find this 2021/2022 season wasn't even a top 10 overall either. One thing of note is how we are quite a way ahead of polar vortex of doom year 2019/2020 at this stage but it was only really getting going at this stage.

2015/2016 was overall the strongest vortex year up to this point whilst 1998/1999 had been weakest overall.

[Don]

1 hour ago, SqueakheartLW said:

2015/2016 was overall the strongest vortex year up to this point whilst 1998/1999 had been weakest overall.

Interesting that 1998/99 was a mild winter too.

Edited January 19, 2022 by Don

[SqueakheartLW]

1 hour ago, Don said:

Interesting that 1998/99 was a mild winter too.

Could have been a colder winter based on the average vortex speed but I think the strong CP La Nina that year was the defining factor of that winter.

Edited January 19, 2022 by SqueakheartLW

[SqueakheartLW]

These charts keep showing this freakishly strong vortex towards the end of the forecast. Looking like this is going to come off. We could be breaking some 10hpa 60N daily zonal wind speed records if this prediction is correct.

Many of the GEFS are going well above the yellow region so very likely we'll be in polar vortex of doom mode soon if this is correct.

Even bias corrected CFS sees near or actual record strong zonal winds until April at least and very likely not seeing the end of the vortex until well into the spring, maybe even May.

If that happens don't expect anything decent weather wise in late spring or the early part of the summer.

Edited January 20, 2022 by SqueakheartLW

[Don]

1 hour ago, SqueakheartLW said:

These charts keep showing this freakishly strong vortex towards the end of the forecast. Looking like this is going to come off. We could be breaking some 10hpa 60N daily zonal wind speed records if this prediction is correct.

Many of the GEFS are going well above the yellow region so very likely we'll be in polar vortex of doom mode soon if this is correct.

Even bias corrected CFS sees near or actual record strong zonal winds until April at least and very likely not seeing the end of the vortex until well into the spring, maybe even May.

If that happens don't expect anything decent weather wise in late spring or the early part of the summer.

Absolutely ridiculous those charts.  So, it sounds like the first half of 2022 is not only looking poor for cold weather lovers but also potentially for those wanting a nice spring and early summer, too!?

[SqueakheartLW]

Seeing these charts showing how strong the zonal winds are and how they are predicted to get even worse

Makes me cast my mind back to last autumn when the main models were all going for weaker than average zonal winds to dominate the winter period.

I bet the people who made those models will be looking rather stupid now and will be eating a bit of humble pie

[SqueakheartLW]

Looks like ECM has other ideas for the polar vortex compared with GEFS and CFS

Lets hope ECM has called this correctly. We could possibly be saved from a polar vortex of doom if ECM has this right.

[summer blizzard]

2 hours ago, SqueakheartLW said:

Seeing these charts showing how strong the zonal winds are and how they are predicted to get even worse

Makes me cast my mind back to last autumn when the main models were all going for weaker than average zonal winds to dominate the winter period.

I bet the people who made those models will be looking rather stupid now and will be eating a bit of humble pie

Fairly sure the Met office has been gung ho on the vortex since very early on so not all good models.

[Don]

5 hours ago, SqueakheartLW said:

Looks like ECM has other ideas for the polar vortex compared with GEFS and CFS

Lets hope ECM has called this correctly. We could possibly be saved from a polar vortex of doom if ECM has this right.

Too late for winter though!

[stodge]

Just a question - looking at the GFS wind speeds, we still see a sudden and dramatic slowing of those speeds in early spring rather than a more gradual lessening.

Wouldn't a sudden slowdown put a lot of pressure on the PV?

I'm still putting in my order of Northern Blocking for April and May.

[SqueakheartLW]

After such boredom with the 10hpa stratospheric charts it's suddenly looking more interesting again. Maybe too late to salvage winter for us unless these come off and we get a very quick tropospheric response to them

GFS 12z warmest warming charts

Op                                                            Control                                                     P4

P8                                                              P16

P8 is my favourite for warmest value but I think the Op one has the best chance of splitting the vortex.

GEM 12z

P4

GEM less keen for the warming but does have this one on P4

 

Maybe if this comes off we can see a quick response and mid to late February could get more interesting if the cards fall right for us.

[Don]

2 hours ago, stodge said:

I'm still putting in my order of Northern Blocking for April and May.

Too bloody late as usual! 

[Cloud 10]

On 15/01/2022 at 08:37, bluearmy said:

well we haven’t seen a chart like this for months - yes I know it’s an op day 16 

 

Why am i thinking of Monty Python?

 

Certainly a beastly PV this winter and set to continue by the look of it,although it will come to the point where it is to strong for its own good....