Stratosphere Temperature Watch 2013/2014

[Snowy L]

Yes, I think we are about to at least buy a ticket, I think these FI trop runs with the trough anchored to the WNW of us will verify though, Ian F and the met say strong signal for a WSW flow now so I think a little bit later before FI corkers start showing though, think that will be hard to shift, I will go about another 5 days before we see some great FI runs showing up Blocking mid feb, one thing bugging me is EP flux charts showing strong equator ward flow though, need that to change.

 

Don't be surprised to see the area in the North Atlantic suddenly free up in 300+ FI of the GFS in the next few days though, similar to how last years tropospheric models responded to last years SSW. Too early to get excited but if we get a good downwelling the positioning of the lobes looks brilliant for a Greenland high. That Baffin Bay lobe that has been troubling us all winter is being pushed way west into USA/Canada and more exciting the Siberian lobe is pushed ominously close to Scandi/UK. There's a good downwelling already in this 18z run with much lighter zonal winds at 100mb by the end of the run

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014012618&var=HGT&lev=100mb&hour=384

[Recretos]

I would have said that but I always seem to be out, very hard to tell unless you have some sort of measuring screen software, plus its hard to tell exactly what point in between the isobars identified as to where the Westerlies become Easterlies, great post from Recretos on this subject with that diagram last night, is he Einstein in disguise!!!

 

:lol: Thanks, but its just simple logic. :DOk, to make it official, the technical SSW occurs at T306.

[feb1991blizzard]

Thanks, but its just simple logic.

Ok, to make it official, the technical SSW occurs at T306.

 

Thanks for your input, and great to see it moving up the chain, hopefully we will see it on the ECM berlin charts in 3-4 days time.

[Interitus]

Latest GFS is far less progressive, no reverse at 10mb and would delay this by many days compared to the previous runs.

[bluearmy]

Latest GFS is far less progressive, no reverse at 10mb and would delay this by many days compared to the previous runs.

Doesn't look bad though with a decent split. Berlin zonal winds in latter stages look more plausible this morning. Less reverse flow than recent days but weak westerlies should allow for blocking where it wants to set up tropospherically.

[nick sussex]

The one thing thats surprised me this winter is just the inconsistency of the signal, last winter when we had that SSW the actual warming remained pretty much on track from the far reaches of FI. This year theres such wild swings in the temperatures shown especially at the 10hpa level.

[Interitus]

Doesn't look bad though with a decent split. Berlin zonal winds in latter stages look more plausible this morning. Less reverse flow than recent days but weak westerlies should allow for blocking where it wants to set up tropospherically.

 

Well the latest Berlin ECM supports a slower evolution. The shortest time in the MERRA dataset to SSW from the 10mb zonal wind of 26.6m/s on the t240 of 25/01 is about three days, while from the 37.3m/s on t240 of 26/01 it is between 5 and 6 days which makes it 3 or 4 days later, though not quite the best part of a week later as on the GFS 0z.

This presentation describes the possibly critical factor of anticyclonic potential vorticity tendency being poleward of the vortex -

https://ams.confex.com/ams/19Fluid17Middle/webprogram/Paper227033.html

Roughly speaking this chart from 25/01 shows the vorticity gradient and some anticyclonic pv between the vortex and the pole promoting an earlier SSW

But in the later run the low pv is struggling (to this point) to get over the pole

 

[UV-RAY]

The one thing thats surprised me this winter is just the inconsistency of the signal, last winter when we had that SSW the actual warming remained pretty much on track from the far reaches of FI. This year theres such wild swings in the temperatures shown especially at the 10hpa level.

A stab in the dark here Nick but I wonder if the uptick in solar output has been responsible for this?

[Gael_Force]

A stab in the dark here Nick but I wonder if the uptick in solar output has been responsible for this?

 

I think it was Lorenzo who posted a graphic from WeatherBell where they showed the analogue patterns for US and Atlantic during each combo of QBO and solar cycle stage. What we have seen so far was identical to the wQBO/solar max state as far as the States were concerned -  the Jet further south through our longitude may be a signal from here on.

[Ruben Amsterdam]

A stab in the dark here Nick but I wonder if the uptick in solar output has been responsible for this?

 

10.7cm solar flux has been stable the last two/three weeks around 135 and expected to rise slightly the next couple of days. 

 

I'm confident the 06z will boost moral again â€‹ 

Edited January 27, 2014 by Ruben Amsterdam

[lorenzo]

Here is the image mentioned by Polar Gael.

 

Keep being drawn back to the OPI image for their prediction of waves with respect to what lies just ahead, 2013 waves from MERRA and also a couple of images from the OPI posts on centrometeotoscanca The CONUS one is pretty striking, not withstanding the Feb. wave activity on the horizon.

z1n_10_2013_merra.pdfz2n_10_2013_merra.pdf

 

 

Another thought, when seeing some of the more progressive warmings on the 06z GFS runs over the last couple of days, was that the vortex looked in bits with what appeared to be irreversible warming. So much so, wondered if rather than MMW we might be about to see an early Final Warming.

 

Looking at the Berlin Data there are precedents for a couple of FWs in February, not a prediction of course just adding to the discussion of how February will play out.

 

1978/79

Zonal Wind / Wave 1 / Wave 2 & Feb composites

u60n_10_1978_merra.pdfz1n_10_1978_merra.pdfz2n_10_1978_merra.pdf

 

Composites for Feb 1979

 

1988/89

As Above

u60n_10_1988_merra.pdfz1n_10_1988_merra.pdfz2n_10_1988_merra.pdf

 

What is clear at present is that NWP output is jittery, usually there is a smooth transition between the development then reverse of trends, seems we are getting lots of cross model variance at shorter time periods than usual. Still a fair bit of Winter to go, evidently due to being in Scotland this idea applies further for my locale, and appreciate the frustration felt by many on the main model thread with respect to time not being our friend.

 

Massive interest though in how February pans out, whilst run to run peaks and troughs exist , the existing wave activity will have continued impact and provide opportunity for further insight.  I think we are going to be damn unlucky not to get atleast decent 7-10 day cold spell during February to give some respite to what has been a frustrating but ultimately interesting winter so far.

 

Edit - add EP - 6th day in a row of poleward EP Flux.

Strat / Trop

 

 

Edited January 27, 2014 by lorenzo

[summer blizzard]

Out of interest do you relative experts expect the stratosphere to stay warm for some time or fall back below average like 2009.

[karyo]

After last night's epic 18z, all of today's GFS run have downgraded the warming.

Karyo

[Guest I'm a superstar]

After last night's epic 18z, all of today's GFS run have downgraded the warming.Karyo

UK already has cold weather now, snowy and about - 10 everyday so why do you want an stratospheric warming?

[Severe Siberian icy blast]

UK already has cold weather now, snowy and about - 10 everyday so why do you want an stratospheric warming?

Sorry but your getting confused with your own country we have barley seen a snow flake all winter and are still waiting .

[bluearmy]

UK already has cold weather now, snowy and about - 10 everyday so why do you want an stratospheric warming?

 

are you the daily express headline writer?

 

below 5hpa, the split remains but there is not going to be a reversal of zonal winds judging by the way the pattern pushes back poleward. above 5hpa, it looks like it would probably reverse in time or at least be almost neutral.

[summer blizzard]

UKMO view appears to be that the best chance of warming was the one forecast to occur in a few days time and that the current signal is less likely to stand the test of time as things stand.

 

 

I think a cautionary note on the strat warming.... it's something UKMO's M-R folk have been watching closely all winter (as you'd imagine). I just asked about this, i.e. re their views on the NCEP signals of late. They tell me: "GLOSEA5, the UKMO seasonal model, doesn't seem to support this event all that much and since it hasn't been working so far this season in terms of getting the warmer air down in reality, this signal isn't being used in relation to forecasting a change to colder periods." 

There was a much more pronounced signal emerging back in earlier Jan (modelled for later Jan and into early Feb, as some on this forum are aware), but that was lost.

 

[DAVID SNOW]

I wonder if Snowballz or fergieweather can now tell us a little more about what Glosea5 was seeing mid January?

 Ian F from the METO has just answered this question over on the MOD thread, its not good news.

[Interitus]

Well the pressure on the vortex has just eased off a little allowing it to recover to an extent, with temperatures tumbling quite noticeably in the last couple of days which may have had an affect on the runs today. Assuming the latest MERRA data to 26/01 is correct, the 10mb temperature at 90° and 80° are now back lower than they've been for the past 25 days.

In the heart of the vortex, the 90° 50mb and 30mb temperatures are where they were 14 and 21 days ago, and are at levels which haven't seen SSW within 16 and 19 days in the MERRA dataset (started Jan 79).

 

Don't need Glosea to work this stuff out! They may a bit premature ruling out an SSW, although it may not be what people want to hear we are still on the early side for an SSW with the current QBO, with the average date nearly a month away.

Edited January 27, 2014 by Interitus

[AWD]

The GFS Operationals continue with the FI split teases, the latest from the 12z;

EC, within it's 10 day timeframe forecasting a notable wave 2 increase;

Whether -

A). This verifies

B ). Has any positive impacts upon the polar patterns

remains to be seen.

[feb1991blizzard]

The GFS Operationals continue with the FI split teases, the latest from the 12z;

image.jpg

EC, within it's 10 day timeframe forecasting a notable wave 2 increase;

image.jpg

Whether -

A). This verifies

B ). Has any positive impacts upon the polar patterns

remains to be seen.

 

 

Problem is though the wave 2 starts to recede by day 10 maybe not strong enough again, I wonder if chiono still thinks we have a chance of an Easterly in Feb after Fergie and interius's latest posts.

Edited January 27, 2014 by feb1991blizzard

[aginob]

good evening

sorry my question

what does mean FI ?

 

thanks

[Yarmy]

good evening

sorry my question

what does mean FI ?

 

thanks

 

It stands for Fantasy Island. It is netweather slang for model output that is too far in the future to have any confidence in its prediction. See here:

 

http://forum.netweather.tv/topic/78022-the-model-dictionary/

[weatherjunkie]

Was looking optimistic over the last few days but less so today.

 

Can't complain though since the E US has been quite cold and snowy. We wouldn't need a full SSW to keep it that way the rest of the winter. The PV has been entrenched into Canada for a while and another lower stratosphere split at some point in the next two weeks would most likely keep things cold. I like the wavebreaking we're seeing in the N. Atlantic. GFS showing warming events coming from that region and hopefully it'll be enough to knock the PV down some more. I've already convinced myself not to pay attention to the 6z forecasts...too much hope that gets dashed away in subsequent runs.

[aginob]

hi everyone

for user yarmy

 

http://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/?p=2910664

 

thanks for link and answer