Stratosphere and Polar Vortex Watch

[chionomaniac]

4 minutes ago, Don said:

So, currently not great then?

No, as BA has suggested we then need to look at the tropospheric precursors to wave 2 activity and these are looking promising. I would be looking at initially week 3 ( end of)  and thereafter for potential, subject to wave 2 activity creating a significant strat event. Without this keep watching because I see a Scandi ridge being a theme this winter.

[Don]

3 minutes ago, chionomaniac said:

No, as BA has suggested we then need to look at the tropospheric precursors to wave 2 activity and these are looking promising. I would be looking at initially week 3 ( end of)  and thereafter for potential, subject to wave 2 activity creating a significant strat event. Without this keep watching because I see a Scandi ridge being a theme this winter.

Thanks for the reply

[Cheshire Freeze]

Displacement or not, it looks as though this warming may severely knacker the vortex

We've also had hints in the extended modelling that we will indeed see a wave 2 attack shortly after.

[ArHu3]

Judah Cohen has made a anomaly charts of the 2 months following a displacement type major ssw

Only 1 out of 7 displacement type ssw since the nineties saw colder than average temperatures in western Europe, all others saw warmer than average temperatures 

 

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

[stodge]

We know vortex displacement doesn't work in our favour in western Europe if the displacement comes from the Siberian side and sends the PV back to Canada/Greenland. Indeed, we can probably assume 7-10 days of mild positive NAO and AO conditions from any such displacement.

Yet the displacement does weaken the PV and renders it susceptible to further Wave 1 and Wave 2 assaults and getting the PV pushed further west opens the door to Scandinavian HP. The question for this winter is how long is it going to take before the PV is so sufficiently disorganised as to allow for blocking to develop - those who advocate a middle to back loaded winter probably have made a sensible call irrespective of whether we get any northerly outbreaks in the interim. 

[Singularity]

You know what, when I think about the knock on effects of models suddenly pushing things east day 5 or 6 onward, I’d not be surprised if the wave 1 warming was being overdone; in a sense, some of what should contribute to a wave 2 pattern instead is being aligned with wave 1... erroneously I figure/hope!

[Interitus]

22 hours ago, Yarmy said:

Shame you can't get the GEFS members archived anywhere (unless I'm mistaken?) as I'd really like to see that -30m/s member. 

181210 0z P17 10mb geop. and temp.

Zonal wind -30.8 m/s at 65°N, -20.3 m/s at 60°N

[snowking]

Some timely tweets from Ventrice - how is this for a 51-member ensemble MEAN warming - temperatures in the -15 to -10 range out at day 15 as an average. The reality could be much much warmer

 

EDIT: Just adding the anomaly view in, in case anyone missed just how significant a projected warming this really is

Edited December 11, 2018 by snowking

[Singularity]

Thanks SK.

Leads me to wonder how this stacks up historically; is it near or at record magnitude? 

Which in turn raises the question - can the usual limitations of a displacement possibly be overcome, at least on a regional extent? I expect that depends on whether there's any mechanism by which the anomalies can propagate downward when the vortex hasn't actually split. TIA

[Met4Cast]

Just wanted to share this from the day 7 ECM op

[MattStoke]

Interested that on the Met Office lunch time video they said they wouldn’t be surprised to see a SSW at the end of the year.

[ALL ABOARD]

1 minute ago, MattStoke said:

Interested that on the Met Office lunch time video they said they wouldn’t be surprised to see a SSW at the end of the year.

Any links would like to watch ? If possible,

[feb1991blizzard]

1 minute ago, MattStoke said:

Interested that on the Met Office lunch time video they said they wouldn’t be surprised to see a SSW at the end of the year.

Did they say say what type of SSW and whether it would affect the UK's weather?

[MattStoke]

Just now, ALL ABOARD said:

Any links would like to watch ? If possible,

Here you go. It’s a bit long but talks about this weekend and then how strat developments can affect our weather.

 

[MattStoke]

1 minute ago, feb1991blizzard said:

Did they say say what type of SSW and whether it would affect the UK's weather?

Not really. They just talked about the strat and strat warming in general and how it can affect us, and then said they wouldn’t be surprised to see a SSW as we end the year.

[northwestsnow]

1 hour ago, Daniel Smith said:

Just wanted to share this from the day 7 ECM op

I cant make out where the warming is on the chart? Looks like a warming is already underway?

[JeffC]

In fact you can just see it starting now...that pale blue bit upper right...where the green circle is..

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-6.43,89.52,327/loc=124.135,62.685

 

Edited December 11, 2018 by JeffC
link wouldn't work

[Met4Cast]

37 minutes ago, MattStoke said:

Here you go. It’s a bit long but talks about this weekend and then how strat developments can affect our weather.

 

The way he says “Stratosphere” really irks me

[bluearmy]

Which one is dec ??

 

[sundog]

 

21 minutes ago, northwestsnow said:

I cant make out where the warming is on the chart? Looks like a warming is already underway?

It's hard to see the continent's  on that chart but it looks like the warming is over Canada. I can make out Alaska and the Aleutian Islands.

[northwestsnow]

3 minutes ago, sundog said:

 

It's hard to see the continent's  on that chart but it looks like the warming is over Canada. I can make out Alaska and the Aleutian Islands.

Thanks Sundog, i thought as much, but wasn't sure..

[Met4Cast]

30 minutes ago, northwestsnow said:

I cant make out where the warming is on the chart? Looks like a warming is already underway?

Canada - Took me a little while too, the chart is from a US perspective rather than European 

[Yarmy]

27 minutes ago, northwestsnow said:

I cant make out where the warming is on the chart? Looks like a warming is already underway?

It's over Canada. The same time chart (albeit GFS rather than ECM) with absolute temps rather than anomalies is much clearer I think.

 

The anomaly version creates the impression that there's a split which obviously isn't the case.

[northwestsnow]

4 minutes ago, Yarmy said:

It's over Canada. The same time chart (albeit GFS rather than ECM) with absolute temps rather than anomalies is much clearer I think.

 

The anomaly version creates the impression that there's a split which obviously isn't the case.

Thanks mate , although its nice to know there isn't a deep PV setting up over that area

[JeffC]

The bit I was looking at shows the warming starting now over North East Russia?