Stratosphere temperature watch - 2016/17

[bluearmy]

as would be expected, vortex at the very top ramping up to 60m/s by day10 but with it displaced at around 40N, will be interesting to see what follows. some wave 2 activity would be nice............

[Nouska]

24 minutes ago, lorenzo said:

Final third of November an intriguing watch

Following on from posts in the snow and ice thread, I was doing a bit of looking back. Striking similarities in the stratosphere forecast to what transpired in November 1976 - the top year, in the record we have, for Eurasian snow cover.

   

The November Canadian warming evident there.

The archived month in continuous, mouse-over format - some shades of what we are seeing in the current modelling. It led on to a cold December and January in that winter - any pointers there for this winter - probably not, but something to watch.

http://www.meteociel.fr/modeles/archives/archives.php?day=1&month=11&hour=0&year=1976&map=4&region=&mode=2&type=ncep

 

[northwestsnow]

28 minutes ago, bluearmy said:

as would be expected, vortex at the very top ramping up to 60m/s by day10 but with it displaced at around 40N, will be interesting to see what follows. some wave 2 activity would be nice............

Indeed, im watching for displacement blue  - interesting few days coming up!

[ArHu3]

6 hours ago, lorenzo said:

Little bit of an uptick and attempt to get in gear, still refusing to commit..

 

I'm a bit rusy with my maths and Fourier but it seems there is decelerating wave.

[bluearmy]

ECM 12z op develops a split vortex (n Siberian master and smaller centre  e of Greenland) by day 9 up to 30 hpa

 

[Singularity]

22 minutes ago, bluearmy said:

ECM 12z op develops a split vortex (n Siberian master and smaller centre  e of Greenland) by day 9 up to 30 hpa

 

I jumped out of my chair and shouted 'Aha!' when that uploaded; I've lately been quite entranced by the idea of the N. Eurasian blocking being able to hold firm as the vortex falls apart around it. ECM hinted at this a couple of days ago but then produced a couple of runs with a deep low powering through Svalbard and flattening the N. Eurasian ridge.

[Glacier Point]

.. Think we may be talking about wave 2 in the coming weeks. Latest run of modelling builds mid tropospheric heights over Eastern Europe / western Russia in the week 2 and 3 period. That's a near perfect amplitude for wave flux into the polar stratosphere.

latest op gfs probably jumping the gun a bit, but you can appreciate where it's getting its signal from.

[Dennis]

10Hpa  - 

[Paul_1978]

What is this showing us then @Dennis? 

[Singularity]

20 hours ago, Glacier Point said:

.. Think we may be talking about wave 2 in the coming weeks. Latest run of modelling builds mid tropospheric heights over Eastern Europe / western Russia in the week 2 and 3 period. That's a near perfect amplitude for wave flux into the polar stratosphere.

latest op gfs probably jumping the gun a bit, but you can appreciate where it's getting its signal from.

With the changes in the atmospheric arrangement marked by GLAAM rising fully into positive territory (right in the face of the oceanic setup), it seems we're making a short term cold weather sacrifice for a long-term gain. Given the positioning that we're at in time, I've no quarrel with that 

[Dennis]

4 hours ago, Paul_1978 said:

What is this showing us then @Dennis? 

Hi i think new round for PV split is near to come @Paul_1978

Edited November 8, 2016 by Dennis

[northwestsnow]

Definite signs of a drop in temps now -

Still above the norm but perhaps reflected in the NWP outputs showing a stronger PV over Greenland...

[Dennis]

zonal winds more down

Edited November 10, 2016 by Dennis

[bluearmy]

Can't be far from a reversal in the 12z op at the end of the run

 

at t

 

[Blessed Weather]

Cohen tweet with a forecast of increased poleward heat flux around 18/19th Nov, hopefully further weakening the polar vortex:

[Allseasons-Si]

On 09/11/2016 at 18:03, northwestsnow said:

Definite signs of a drop in temps now -

Still above the norm but perhaps reflected in the NWP outputs showing a stronger PV over Greenland...

There is an uptick on the 10 hpa though northwestsnow,will see tomorrow if this gains further.

Edited November 10, 2016 by Allseasons-si

[Singularity]

18 hours ago, Blessed Weather said:

Cohen tweet with a forecast of increased poleward heat flux around 18/19th Nov, hopefully further weakening the polar vortex:

Good signs indeed. I wonder if that plot is taken from an ensemble mean or just the det. run?

The models really do have their work cut out for them; it's one thing figuring out how an organised vortex might displace or split in response to heat fluxes, but to figure out how an already highly disorganised vortex will move about... I suppose it could be like trying to resolve several vortexes at once!

Despite the differences in situation, we seem to be witnessing the usual model behaviour in terms of how they treat blocking signals i.e. "it's there, I know it, but I've only the vaguest idea when it will actually manifest!"

[Weather-history]

 

[Summer Sun]

 

[bluearmy]

Anyone have any verification stats for the upper strat 

just dug out some screenshots for day 10 ECM forecast for Nov 2 and they really were spot on for 10,30 and 50 hpa

[feb1991blizzard]

4 hours ago, bluearmy said:

Anyone have any verification stats for the upper strat 

just dug out some screenshots for day 10 ECM forecast for Nov 2 and they really were spot on for 10,30 and 50 hpa

Not sure if you might find something in amongst this lot.

http://www.ecmwf.int/sites/default/files/elibrary/2015/15275-evaluation-ecmwf-forecasts-including-2014-2015-upgrades.pdf

 

[sebastiaan1973]

http://m.uploadedit.com/ba3s/1478101037778.pdf yet another forecast for a double sided winter. First part more chance for cold, negative NAO, second part probably warmer with postive NAO.

[karyo]

20 minutes ago, sebastiaan1973 said:

http://m.uploadedit.com/ba3s/1478101037778.pdf yet another forecast for a double sided winter. First part more chance for cold, negative NAO, second part probably warmer with postive NAO.

Is he a meteorologist?

Looking at this, it wouldn't take a huge shift in the pattern to make Jan and Feb more promising as it seems to keep low pressure to the South and high over Scandinavia.

[bluearmy]

Not sure this the right thread for winter forecasts?

(looks good to me though - If Europe maintains low anomolys then tough for us not have a wintry season)

[karyo]

Both the 0z and 6z gfs look similar in the final stages with the main vortex in Siberia. Unfortunately, a secondary one is left around Greenland which we could do without.