Stratosphere and Polar Vortex Watch

[Don]

5 minutes ago, Mike Poole said:

Yes, quite! There's quite a few things I want put out of action next winter, starting with the +IOD, west QBO (should be guaranteed that one), and adverse SSTs in the N Atlantic - that ones the worry for me.  But we have to have better luck next year, Don, surely!

Well, it's unlikely to be any worse and if it's similar, that would be awful!  I think the PDO and N Atlantic SST's are the main concerns for next year, although the PDO has recently showed signs of cooling down.  However, we need to see that continue and watch for the development of a tripole in May.

Edited February 8, 2020 by Don

[DavidS]

GFS has been playing with this idea over the last few runs. Yes it is deepest FI, but perhaps something to keep an eye on.

[mb018538]

6 hours ago, DavidS said:

GFS has been playing with this idea over the last few runs. Yes it is deepest FI, but perhaps something to keep an eye on.

Not really - that’s the end of winter anyway. There’s been pulses of wave 1 warming this winter, but the monster PV has gobbled them up and spat them out.

[mb018538]

Zonal winds forecast to be the strongest on record into next week, and staying strong right out until the end of the month. Seeing speeds up around 60m/s is quite something for mid-late Feb.

CFS has 4 members going for a SSW into March, but the mean still stays above average right into late March:

[Kirkcaldy Weather]

 

[DavidS]

The GFS is still toying with the idea of a warming. The 00z run shows a nice progression from 288hrs to the end of the run, however the PV still looks rock solid and the warming probably not significant.

 

 

[summer blizzard]

March 13th-April 10th are the years that fit us.

If we don’t get one in that period then April 19th-May 8th.

[joggs]

So it could be a summer buster?

 

[mushymanrob]

3 hours ago, joggs said:

So it could be a summer buster?

 

no...... theres no correlation that i can see between a late ssw and a good/bad summer...  good summer with a late ssw - 84,89,06,13.  bad summers with a late ssw 04,07,08,

[stodge]

Evening all

While I gladly acknowledge Amy Butler's wisdom in all this, the TPV at the moment puts us in uncharted waters. The question for me is whether it will effectively spin itself out in a strong early final warming or gradually dissipate over a long period.

IF we get a rapid and powerful final warming in March I would expect an extended period of northern blocking through April and May.

If the dissipation is longer and slower I'd expect more "typical" weather patterns (which would still mean HLB to the north as that's not atypical of spring).

Some of the CFS longer range charts continue to play with the idea of a much weakened and distorted TPV decamping to Siberia and beyond in mid March - well, perhaps but that's a very long way off.

[stodge]

No hint of any warming as we move into March with 10 HPA temperatures still at or below -68c at the core.

I suspect, contrary to what I thought earlier, March will be a continuation of February in terms of it being a broadly westerly regime with little or no HLB.

Cold Easter anyone?

 

[Interitus]

A review of the 2018/9 stratosphere by Simon Lee and Amy Butler (free access) -

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3643?hootPostID=e556789f8449e0151927809065bece99

 

[stodge]

29 minutes ago, Interitus said:

A review of the 2018/9 stratosphere by Simon Lee and Amy Butler (free access) -

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3643?hootPostID=e556789f8449e0151927809065bece99

 

Thank you, my friend. How soon we forget some things.

I'd forgotten how strongly the SPV responded to the SSW of January 2019 and it recorded a record wind speed in March let alone February.

I wonder if the fall away via the FW will be similar this season but perhaps a little earlier with an FW in early April - we'll see.

[bluearmy]

Date record today ?.

broke 1988 number 

[knocker]

A very cold and symmetrical vortex at the moment as shown by the 10 and 50mb plots. Difficult to illustrate this with a sounding but Danmarkshavn in NE Greenland does show the difference between the two levels as well as the cold at 50mb, -85C

[snowblizzard]

2 minutes ago, knocker said:

A very cold and symmetrical vortex at the moment as shown by the 10 and 50mb plots. Difficult to illustrate this with a sounding but Danmarkshavn in NE Greenland does show the difference between the two levels as well as the cold at 50mb, -85C

Wow, that's intense!

What temperature would you expect from that at 2 metre level?

[Interitus]

2 minutes ago, snowblizzard said:

Wow, that's intense!

What temperature would you expect from that at 2 metre level?

-26.7°C

[joggs]

4 hours ago, Interitus said:

-26.7°C

Great news for the arctic ice then one would think.

[bluearmy]

On 17/02/2020 at 07:26, bluearmy said:

Date record today ?.

broke 1988 number 

And again today .....

[Weather-history]

I wonder if the polar vortex was as intense as this 30 years ago? Late January to start of March 1990 was stormy at times,  a very active period of weather. 

[mb018538]

1 hour ago, Weather-history said:

I wonder if the polar vortex was as intense as this 30 years ago? Late January to start of March 1990 was stormy at times,  a very active period of weather. 

Vortex was pretty strong in that period - well above average through January, before a bit of a roller-coaster in Feb!

[Weather-history]

2 minutes ago, mb018538 said:

Vortex was pretty strong in that period - well above average through January, before a bit of a roller-coaster in Feb!

Thanks, not as strong as I thought it would be at least the stratospheric polar vortex.

NAO for Feb 1990 was 1.41 and AO was 3.4

 

[knocker]

Not to forget that the tpv has also been a fairly tightly knit affair which resulted in 'locking' up the cold air whilst at the same time turning the western Atlantic into a very active baroclinic zone. This not only resulted in some very intense cyclogeneisis but also. from time to time, the transport of very moist air over the UK leading to copious amounts of rain

[karyo]

23 hours ago, joggs said:

Great news for the arctic ice then one would think.

I was thinking that too but once again it is well below average. I guess the problem is that even with the cold bottled up there, the warmer ocean water puts a stop on the ice extending.

Charctic Interactive Sea Ice Graph | Arctic Sea Ice News and Analysis

NSIDC.ORG

 

[bluearmy]

16 hours ago, bluearmy said:

And again today .....

And for a third day ......