Stratosphere Temperature Watch 2015/2016

[bluearmy]

The axis of the stretched displaced vortex in two weeks time beginning to give a cross polar flow down the meridian.  This is interesting as it fits in with recent trop modelling at the end of the month where low heights appear to drain away from Canada in general.  That a long way off in NWP terms but it begins to tie in with what GLOSEA must be seeing re Ian's hints and the meto 30 dayer as we head through feb. 

[northwestsnow]

1 hour ago, bluearmy said:

The axis of the stretched displaced vortex in two weeks time beginning to give a cross polar flow down the meridian.  This is interesting as it fits in with recent trop modelling at the end of the month where low heights appear to drain away from Canada in general.  That a long way off in NWP terms but it begins to tie in with what GLOSEA must be seeing re Ian's hints and the meto 30 dayer as we head through feb. 

The low heights over canada were a constant pain last year and this year blue.

Its been another winter with a rampant PV

[karyo]

1 hour ago, bluearmy said:

The axis of the stretched displaced vortex in two weeks time beginning to give a cross polar flow down the meridian.  This is interesting as it fits in with recent trop modelling at the end of the month where low heights appear to drain away from Canada in general.  That a long way off in NWP terms but it begins to tie in with what GLOSEA must be seeing re Ian's hints and the meto 30 dayer as we head through feb. 

Sadly the meto 30 dayer has changed to day to something a lot less interesting.

The main positive I see in the models so far today is the stratospheric warming causing a vortex displacement towards Asia but this is still too far away (300 hours).

[blitzen]

Not sure if any of you folks in here have heard the Joe B Saturday summary?   He talks about an expected strat warming and I definitely heard Netweather get a mention.   Don't shoot the messenger!  Around the 6min mark.

[bluearmy]

Just now, Blitzen said:

Not sure if any of you folks in here have heard the Joe B Saturday summary?   He talks about an expected strat warming and I definitely heard Netweather get a mention.   Don't shoot the messenger!  Around the 6min mark.

My experience of joe b' and weatherbell is that his appreciation of the strat is rather lower than that displayed on here by ed , Andrej et all. 

he does use NW 30hpa charts to illustrate warmings . Up until yesterday, he usually referred to them as being 'UKMET' charts. At least he now references correctly re NW. 

[Weather-history]

Dr Cohen 

@nj_strong_wx I think we could be looking at a fairly robust SSW even major. But I am surprised how much the GFS is all over the map.

2:28pm - 17 Jan 16

[Singularity]

An entertaining 06z GFS(P) at 10 hPa for example:

Kind of like a trial run, this bout of warming peaks on 28th at -12*C. Enough to bother the strat at that level quite a bit in the space of 2 days:

...but then comes the second effort that the operational model keeps toying with... and the parallel takes it to the top of the scale:

I gather this experimental version is a bit over the top with temp rises in the strat (I seem to recall it suggesting an early Jan SSW at some point in Dec), but even so, it's nice to see such dramatic charts and speculate over what it would achieve down the line...

This seems to be a large displacement event driven from the Eurasian side, which have a habit of not displacing the PV far enough to do us much good... but the above is such a large, fast shove that I imagine the vortex would have a job holding together. 

 

 

I wonder, though, whether the manifestation of warming might be significantly altered should the Kara high prove more resilient that currently modelled, as has been a trend of recent times?

Watching the 12z GFS det. at 10 hPa now... out to 210 h and up to -20*C, a little behind the 06z det. but of course we kind of expect to see that.

 

[lorenzo]

ECM taking us out until nearly the end of Jan now and the dilution of the rampant vortex continues.

u wind reducing significantly, albeit not to technical SSW more MMW event or one of the other categories.

W1 strongest have seen this season, I think, fits in with the ever so gradual displacement.

And fluxes, we 'nearly' have a poleward EP Flux, more vertical on this plot vs. equatorward.

Real interest now things are within ECM range to see how it models things toward end of Jan, can events appreciate or is this as good as it gets versus the monster vortex this season. 

[Recretos]

GFS parallel going over the top again. 

   

[Interitus]

There is repeated mention of mountain torques in this thread. Where are these being seen and what have they got to do with stratosphere warming?

[chionomaniac]

They are classic SSW precursors with wave deflection into the strat following +ve EAMT

 

see post here from Ant Massiello which gives an excellent description of current pattern 

 

[ALL ABOARD]

Wont let me post charts from GFS 12z but from T324 onwards can that be classed as a major strat warming?

 

Edited January 18, 2016 by ALL ABOARD

[KyleHenry]

1 hour ago, ALL ABOARD said:

Wont let me post charts from GFS 12z but from T324 onwards can that be classed as a major strat warming?

 

In short yes, but the exact details of Temperatures/energy are not confirmed. 

What makes this a possible major SSW is longevity of the strong PV and the combination of wave 1 followed by Mountain torque event.

Very exciting to observe.

[DAVID SNOW]

8 hours ago, chionomaniac said:

They are classic SSW precursors with wave deflection into the strat following +ve EAMT

 

see post here from Ant Massiello which gives an excellent description of current pattern 

 

Quick  question, do mountain torques have similarities to WAA?  If its a daft question please ignore. Higher up  but producing similar things?

Edited January 18, 2016 by DAVID SNOW

[chionomaniac]

Just now, DAVID SNOW said:

Quick  question, do mountain torques have similarities to WAA?  If its a daft question please ignore.

It's not a daft question. The mountain torques don't - that is essentially to do with gain and loss of earths momentum through position of pressure cells. However, in the case of WAA say into Greenland then we see Rossby wave breaking into latitudes further north or south. Gravitational MT induced wave breaks are upwards and height based into the stratosphere and the compression of the wave creates the majority of the warming, as opposed to warm air being advected in Rossby wave breaks.

 

https://www.jstage.jst.go.jp/article/jmsj/86/5/86_5_613/_pdf

[DAVID SNOW]

9 minutes ago, chionomaniac said:

It's not a daft question. The mountain torques don't - that is essentially to do with gain and loss of earths momentum through position of pressure cells. However, in the case of WAA say into Greenland then we see Rossby wave breaking into latitudes further north or south. Gravitational MT induced wave breaks are upwards and height based into the stratosphere and the compression of the wave creates the majority of the warming, as opposed to warm air being advected in Rossby wave breaks.

 

https://www.jstage.jst.go.jp/article/jmsj/86/5/86_5_613/_pdf

Thank you for the reply! will now  go away and read up on this( that's a first)

[Weather-history]

I notice Dr Cohen has updated his weekly analysis. Makes interesting reading.

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

 

Edited January 18, 2016 by Weather-history
.

[damianslaw]

A lot of warm air advection is projected to enter the arctic over the foreseeable , a similar scenario to what occurred on Boxing Day - with tropical maritime air heading north from the azores region as well. This is likely to hit the PV hard I imagine.

[snefnug]

I have just read the report and I am not seeing anything but ''mild' or 'warmer' for Northern Europe (this including UK).  Am I mistaken in this?

[ukpaul]

1 minute ago, snefnug said:

I have just read the report and I am not seeing anything but ''mild' or 'warmer' for Northern Europe (this including UK).  Am I mistaken in this?

Look at the map (small I know) and it shows the UK in blues (cooler) as per Europe, with our surrounding water pink (warmer). Northern Europe refers to Scandinavia and Northern Russia.

[feb1991blizzard]

Reversal (or near to) at 1mb on the 18z GFS run.

[Gazza H]

2 minutes ago, feb1991blizzard said:

Reversal (or near to) at 1mb on the 18z GFS run.

Whats meant by reversal Blizzard?

[Snowman.]

14 minutes ago, Gazza H said:

Whats meant by reversal Blizzard?

West → East is the standard wind trade a reversal is East → West usually followed by a breakdown of the Polar Vortex which promotes blocking. This is at 10hpa at 60N.

 

Edited January 18, 2016 by SN0WM4N

[feb1991blizzard]

Just now, Gazza H said:

Whats meant by reversal Blizzard?

I should have said zonal mean reversal at 60N tbh, its the average wind speed all the way around the globe at a given latitude, it has nearly gone Easterly (reversal) on the 18z right at the very top of the stratosphere, if that was to be repeated further down (10mb), that would be a technical SSW, I don't know if this chart may help.

 

This doesn't show anything like a reversal at this stage because this only goes out to 240 hours, it may (hopefully) show a reversal within the next week or so, down the left hand side is the height in the atmosphere (1mb is about 150000ft very roughly, this depends on longitude and temperature I think), 1000mb is obviously near the surface), the x axis represents the latitude, the colour code is red for westerly winds and blue for Easterly, so as and when the blue colours show at 10mb, that is classed as an SSW, it doesn't mean that its Easterly all the way around the globe at 60n, its averaged out.

[Chris1986]

6 minutes ago, feb1991blizzard said:

I should have said zonal mean reversal at 60N tbh, its the average wind speed all the way around the globe at a given latitude, it has nearly gone Easterly (reversal) on the 18z right at the very top of the stratosphere, if that was to be repeated further down (10mb), that would be a technical SSW, I don't know if this chart may help.

 

This doesn't show anything like a reversal at this stage because this only goes out to 240 hours, it may (hopefully) show a reversal within the next week or so, down the left hand side is the height in the atmosphere (1mb is about 150000ft very roughly, this depends on longitude and temperature I think), 1000mb is obviously near the surface), the x axis represents the latitude, the colour code is red for westerly winds and blue for Easterly, so as and when the blue colours show at 10mb, that is classed as an SSW, it doesn't mean that its Easterly all the way around the globe at 60n, its averaged out.

Dunno if this helps, is from 12z experimental though.