Stratosphere and Polar Vortex Watch

[knocker]

18 minutes ago, Singularity said:

I'm sure I've seen somewhere or other, perhaps on this forum or maybe the ASI forum, a proposition that greenhouse gases, by reflecting back down a significant proportion of the longwave radiation from the surface, are leading to stratospheric cooling. The past few winters sure seem to support that theory but 'a few cases does not a warehouse make' (or whatever the phrase is...).

In fact with the warmed troposphere I wonder if we may be locked into having a generally more variable vortex than in times past that often tends toward one extreme or the other, as a weaker lower vortex either interacts or remains disconnected from a stronger upper vortex?

Stratospheric Cooling and Tropospheric Warming - Revised

Edited January 11, 2018 by knocker

[Blessed Weather]

Interesting comparison between this year's SPV behaviour at 10hPa 60N and previous years with a similar pattern that resulted in a SSW. I note that 4 out of the 5 similar years were also e-QBO. Hopefully we can add 2017/18 to this analysis, making it 4 out of 6 years with a SSW!

 

[Singularity]

12 hours ago, knocker said:

Stratospheric Cooling and Tropospheric Warming - Revised

Thanks for this 

The implication of adding more molecules to collide with one another is not one that came up in my meteorological studies but then that didn't really cover the stratosphere (shocking isn't it? ). 

Another line on CO2's curriculum vitae of devious doings .

 

 

10 hPa warming launchpad is now at 9 day's range in the GFS output and it was very much evident in the ECM 12z of yesterday at day 10. If I'm recalling correctly, it's the first example in a good few years to have initiated in a region that extends across southern UK. Wouldn't it be nice if a major anomalous stratospheric ridge could set up just NE of us and encourage a tropospheric response along the same lines. Anyway - stratospheric ridge on the Pacific side still looking strong in the ECM so you'd think the vortex would end up seriously stretched at least for a time as the new warming builds on the W. Eurasian side. Depends, of course, on there being corresponding geopotential height rises.

[jules216]

59 minutes ago, Blessed Weather said:

Interesting comparison between this year's SPV behaviour at 10hPa 60N and previous years with a similar pattern that resulted in a SSW. I note that 4 out of the 5 similar years were also e-QBO. Hopefully we can add 2017/18 to this analysis, making it 4 out of 6 years with a SSW!

 

this is the geopotential height anomaly in Februaries for the years with SSW (1979,1980,2001)

[jules216]

1 minute ago, jules216 said:

this is the geopotential height anomaly in Februaries for the years with SSW (1979,1980,2001)

and the years with no SSW - 1982,1997

[karyo]

28 minutes ago, jules216 said:

and the years with no SSW - 1982,1997

So we really need this SSW to happen!

[ArHu3]

31 minutes ago, karyo said:

So we really need this SSW to happen!

1997 without a SSW was remarkably cold though (last year we had a 11 cities your  which only happens in the coldest of winters) but 1980 and 2001 with ssw were quite mild

Edited January 12, 2018 by ArHu3

[karyo]

4 minutes ago, ArHu3 said:

1997 without a SSW was remarkably cold though (last year we had a 11 cities your  which only happens in the coldest of winters) but 1980 and 2001 with ssw were quite mild

1997 was very mild here.

[Glacier Point]

42 minutes ago, karyo said:

So we really need this SSW to happen!

Nope.

Other likely forcing factors are at play.

Exceptional agreement between EPS, GEFS and balance of GFS ops right now on the placement and magnitude of warming.

No SSW forecast as yet, and mindful of the composites for IO forcing, we could maintain status quo for some time. Any official warming not likely until early Feb, when just as it happens the MJO may well be in favourable phases 7 and 8.

[Snowjokes92]

16 minutes ago, Glacier Point said:

Nope.

Other likely forcing factors are at play.

Exceptional agreement between EPS, GEFS and balance of GFS ops right now on the placement and magnitude of warming.

No SSW forecast as yet, and mindful of the composites for IO forcing, we could maintain status quo for some time. Any official warming not likely until early Feb, when just as it happens the MJO may well be in favourable phases 7 and 8.

Whats the usual pattern for phase 7 and 8 on our shores? I could be wrong but wasnt we in similar phases last month

[feb1991blizzard]

21 minutes ago, Snowjokes92 said:

Whats the usual pattern for phase 7 and 8 on our shores? I could be wrong but wasnt we in similar phases last month

Here are the Jan and Feb phase 7 & 8 composites - Feb probably more relevant given GP's post but the only problem is these aren't filtered for Nina - cant find those, ive only got the nino ones and the nina can sometimes mute the signal.

 

JAN

FEB

Edited January 12, 2018 by feb1991blizzard

[lorenzo]

5 hours ago, feb1991blizzard said:

Here are the Jan and Feb phase 7 & 8 composites - Feb probably more relevant given GP's post but the only problem is these aren't filtered for Nina - cant find those, ive only got the nino ones and the nina can sometimes mute the signal.

 

JAN

FEB

Here is a link with some Nina / Nino / Nada Composites   http://www.meteonetwork.it/models/mjo/

 

Jan 7 /8

Feb 7 / 8

Let's hope for some really cool timing and the vortex getting fluxed in tandem with MJO going into the holy grail phase simultaneously... now what would that look like

[lorenzo]

7 hours ago, Glacier Point said:

Nope.

Other likely forcing factors are at play.

Exceptional agreement between EPS, GEFS and balance of GFS ops right now on the placement and magnitude of warming.

No SSW forecast as yet, and mindful of the composites for IO forcing, we could maintain status quo for some time. Any official warming not likely until early Feb, when just as it happens the MJO may well be in favourable phases 7 and 8.

Have you rolled forward any composites yet Stewart...

[comet]

Still no sign as yet of the forecasted warming having much of an impact. The warming at present just seem to be skirting the surf zone. Of course this could soon change, hopefully.

[karyo]

4 hours ago, comet said:

Still no sign as yet of the forecasted warming having much of an impact. The warming at present just seem to be skirting the surf zone. Of course this could soon change, hopefully.

Looking at the 30hpa level it seems that the warming has been downgraded in recent runs.

[Weather-history]

Can we say that the stratosphere has had any impact of what we've seen this winter thus far? 

[Singularity]

I am off the impression that a SSW is dependent on AAM rising sufficiently in GWO phase 3 - something not yet depicted by GFS/GEFS, be that rightly or wrongly so.

[Blessed Weather]

Encouraging tweet from Amy Butler, holding out some remaining hope of a possible SSW by end January. GEFS with 5 out of 21 members showing a reversal of Zonal Wind at 10hPa 60N. Although it should be noted that the overnight 0z GEFS (15/01/18) run also has 8 out of 21 members showing the SPV Zonal Winds stronger than the ERA interim long term average for 30th January.

Continuing the good news, the GEFS show an almost constant disturbance to the SPV from Wave 1 activity during January. Charts for 16th, 18th and 29th Jan:

Some Wave 2 activity but to my eye not quite the strength we would wish for. Charts for 16th, 24th and 29th:

But at least the overall effect is to keep up the disturbances on the SPV so that by end January it is under duress and stretched. Charts for 15th (48 m/s), 19th (27 m/s) and 30th (34 m/s):

Later today I hope to get the time to copy this post over to the excellent new Learning Thread started by @Bring Back1962-63 where I would like to continue discussions and ask questions about the above. Of course input on this thread from our Strat experts very welcome!

[Snowy Hibbo]

On 14/01/2018 at 07:11, Singularity said:

I am off the impression that a SSW is dependent on AAM rising sufficiently in GWO phase 3 - something not yet depicted by GFS/GEFS, be that rightly or wrongly so.

Do you really believe GEFS on this, given its -AAM bias? I think a movement to GWO Phases 3&4 is certainly plausible, and could become more and more likely, as we move into February.

[Singularity]

3 minutes ago, Snowy Hibbo said:

Do you really believe GEFS on this, given its -AAM bias? I think a movement to GWO Phases 3&4 is certainly plausible, and could become more and more likely, as we move into February.

Yes, that move to 3-4 is the favoured outcome by the majority of expert minds as far as I can see and I have little reason to disagree with that; just keeping my options open is all.

ECM supporting the wave-2 forcing, similar strength to GFS. Just needs a bit more oomph and again the 3-4 GWO plays into that. Feasible that the models are overlooking first the tropospheric response to this and then the increased stratospheric impacts that would result.

[JeffC]

Not sure how relevant this is but see below https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-20.19,89.15,327/loc=107.194,59.469 showing an area significantly warmer than surroundings at 10 Hpa....

 

 

[Singularity]

@JeffC I believe what's shown there is derived from GFS although I could be wrong. It matches up well with GFS 12z initialisation temperatures.

[JeffC]

2 minutes ago, Singularity said:

@JeffC I believe what's shown there is derived from GFS although I could be wrong. It matches up well with GFS 12z initialisation temperatures.

yes it does match well, might this be the first showing of some form of warming event, sudden or otherwise?

[mountain shadow]

11 minutes ago, Singularity said:

@JeffC I believe what's shown there is derived from GFS although I could be wrong. It matches up well with GFS 12z initialisation temperatures.

It can't be wrong if its an initialisation can it? And it does show a warming in place?

Very confusing.

[Blessed Weather]

Disappointing. Whilst the Ural ridging/blocking with downstream troughing near the Aleutians is this week providing the strongest pulse of Wave energy into the stratosphere so far this season, it's not looking like providing the knock out blow to the Vortex required for a SSW. The Wave activity graph ticks down for the remainder of the month, so I guess it's onwards into February for another opportunity.

Wave amplitude at 10hPa - graph to Jan 30th:

http://weatheriscool.com/index.php/stratospheric-forecast-wave-series/