Autumn & Winter 2023---2024 Stratospheric Polar Vortex. Events, Analysis, Discussions AND Outlooks

[blizzard81]

34 minutes ago, bluearmy said:

Possible Canadian warming would usually be positive for nw European cold 

Cool. Was it 1962 that is notorious for the Canadian warming?

[Don]

1 hour ago, blizzard81 said:

Cool. Was it 1962 that is notorious for the Canadian warming?

Another potential positive is that the sun seems to be rather sleepy at the moment, too?

[summer blizzard]

11 minutes ago, Don said:

Another potential positive is that the sun seems to be rather sleepy at the moment, too?

No, near solar maxima. 

https://spaceweather.com/

[Redbull165]

43 minutes ago, Don said:

Another potential positive is that the sun seems to be rather sleepy at the moment, too?

Indeed. The number of sunspots have gradually decreased in the last 15 days.

 

 

[Don]

13 hours ago, summer blizzard said:

No, near solar maxima. 

https://spaceweather.com/

We may be nearing solar maximum, but activity has been relatively quiet recently.  However, it will pick up again at some point.

[Dorsetbred]

1 hour ago, Don said:

We may be nearing solar maximum, but activity has been relatively quiet recently.  However, it will pick up again at some point.

It's at its 11 year point this year...

Edited October 30, 2023 by Dorsetbred

[blizzard81]

16 hours ago, Don said:

Another potential positive is that the sun seems to be rather sleepy at the moment, too?

I bet that changes over the next few weeks lol.

[Don]

1 hour ago, blizzard81 said:

I bet that changes over the next few weeks lol.

More than likely as being this close to maximum means the chances are, any quieter spells will be short lived!

[blizzard81]

2 hours ago, Don said:

More than likely as being this close to maximum means the chances are, any quieter spells will be short lived!

Exactly Don. We just know it. 

[Don]

3 hours ago, blizzard81 said:

Exactly Don. We just know it. 

I wouldn't worry, as even if the sun remains quiet, something else will scupper the chance of cold!

[blizzard81]

10 hours ago, Don said:

I wouldn't worry, as even if the sun remains quiet, something else will scupper the chance of cold!

You probably aren't wrong there. We've been scolded too many times lol. 

[MattH]

Bringing this back on topic, but keep tabs on the daily updates from the EC Ext looking ahead. The anomalies continue to favour blocking over W Russia and the Urals, to what extent any wave breaking and activity takes place in disrupting the strat or creating some sort of warming event is, clearly, uncertain, but as we can see since the middle of last week the signal is increasing through late Nov and early Dec period.

Any sort of early winter warming event is often rare, but such a strong +ve temp anom at 10hPa simply can't be ignored, despite the long lead time, especially when you investigate further and acknowledge there are some tropospheric links as well, given expected broader blocking patterns.

27th Nov to 4th Dec

4th to 11th Dec

With the MJO set to remain in phase 8/1, more like phase 8 IMO, then if reanalysis of this phase, in Nov, in a Nino year is anywhere near correct then the two broader anomalies stand out like a sore thumb and those being the Ural/W Russian blocking and the likely progression towards an Aluetian trough.

Just one piece of the jigsaw of course, but as we all know Nov and into Dec (forget the rest of the winter for now) is the key period, annually, for the RI of the sPV, if that suddenly organises and strengthens and down wells with an increased W'ly connection between the strat and trop then, usually, the first half or 2/3 of Dec is a right off for any winter synoptics. (Out of interest, I don't expect that to happen this year anyway, but you know what I mean...)

Regards, Matt.

[summer blizzard]

Creddit to Twitter.

[bluearmy]

Ec46 offers its first view of 11/18 dec at 10hpa - highest anomoly extends towards the Canadian sector 

[Mike Poole]

25 minutes ago, bluearmy said:

Ec46 offers its first view of 11/18 dec at 10hpa - highest anomoly extends towards the Canadian sector 

Overall I thought today’s run looked a slightly more muted signal than the last few days runs.  

[blizzard81]

29 minutes ago, bluearmy said:

Ec46 offers its first view of 11/18 dec at 10hpa - highest anomoly extends towards the Canadian sector 

Indeed. Chart posted for all to see. I wonder if this is a factor with regards some of the seasonal models showing favourable winter synoptics in January. 

 

3 minutes ago, Mike Poole said:

Overall I thought today’s run looked a slightly more muted signal than the last few days runs.  

I agree with regards to the height anomalies (less/no blocking to our north west) but the warming up top doesn't look to have downgraded. 

[Mike Poole]

8 minutes ago, blizzard81 said:

I agree with regards to the height anomalies (less/no blocking to our north west) but the warming up top doesn't look to have downgraded. 

It has downgraded a little, if you compare week 4-11 Dec with previous runs:

(Maybe as a result of less blocking earlier in the run.) Still trying to get an idea of how much random run to run variability there is with plots like this, now we see a run a day.

Edited November 2, 2023 by Mike Poole

[blizzard81]

4 minutes ago, Mike Poole said:

It has downgraded a little, if you compare week 4-11 Dec with previous runs:

(Maybe as a result of less blocking earlier in the run.) Still trying to get an idea of how much random run to run variability there is with plots like this, now we see a run a day.

You are correct there. Let's hope that it doesn't carry on in that vain in subsequent runs. 

[bluearmy]

22 minutes ago, Mike Poole said:

Overall I thought today’s run looked a slightly more muted signal than the last few days runs.  

The zonal slowdown at 10hpa is perhaps a little less enthusiastic but it will swing a little at this range

today is the first look at 11/18 dec which is the basis of my post - where is the anomoly headed over time 

[Don]

1 hour ago, blizzard81 said:

You are correct there. Let's hope that it doesn't carry on in that vain in subsequent runs. 

It had better bloody not, or else!! 

[Catacol]

For anyone wondering what the thinking behind the Ural High, Aleutian Low pattern that several of us bang on about - this is a good read. 

What’s that coming over the hill, is it a weak vortex? – Simon H. Lee

SIMONLEEWX.COM

---

Only a few years ago, ECMWF's then-twice-weekly 51-member extended-range forecasts were not publicly available -- something that is almost hard to...

 

[bluearmy]

Ec46 has recovered more of the high 10hpa anomalies today backend November 

looking at the ec clusters, there are two larger ones - one with a Russian ridge and one with a Russian trough week 2

The Russian ridge is obvs better for wave breaking into the strat 

[Rain All Night]

We seem to have a likelihood of above-average (and perhaps significantly above-average) vortex strength throughout November:

Is that likely to be why the EC46 then starts showing low height anomalies around Greenland in late November and early December?

[bluearmy]

Institute of Meteorology - Working Group Atmospheric Dynamics - Stratosphere Diagnostics

USERS.MET.FU-BERLIN.DE

We have Berlin data back !

I have a query about the 10hpa charts though - the mean zonal wind at 10hpa seems way too low (on both the heights chart and also the zonal flow cross section ) 

gfs has it pretty much double the Berlin figure as does the ec46 zonal flow chart 

am I missing something?

[DavidS]

GFS is consistently showing a warming of sorts at the back end of its run

Thus nicely matches the anomaly on the EC extended for week commencing 20th Nov.