Stratosphere and Polar Vortex Watch

[Weather-history]

 

[JeffC]

14 hours ago, JeffC said:

Apologies, I'm struggling to post pics from my PC...but if you follow the link it should set it all up for you!

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=5.87,90.25,327/loc=109.790,44.598

What I'm seeing here is that the LP Polar Vortex has already been shoved off "Pole Position" by the HP which is warmer than the LP PV.

Then if you look where I've placed the marker, there's an area that's much warmer than the surroundings - OK -29C isn't warm but comparatively it is against -72C.

Is this wave 2 starting already or is a little knowledge a dangerous thing?

 

 

This is what I was meaning... A tad warmer this morning 

Edited December 21, 2018 by JeffC

[Summer Sun]

 

[BlueHedgehog074]

Some absolutely devine posts in here from the likes of @Singularity , @Catacol, @Interitus and many others. Keep up the sound work guys. Can learn a lot of handy information regarding the Stratosphere and its warming and cooling events in here. 

(Edit: sorry about the ‘’ in the post after @Singularity - not sure what happened there. ) 

Edited December 21, 2018 by DiagonalRedLine

[Man With Beard]

FV3 tonight - weakest vortex ever going into January!

[JeffC]

26 minutes ago, Man With Beard said:

FV3 tonight - weakest vortex ever going into January!

Works for me!

[JeffC]

Temps rising at 10 Hpa see marker refs

[phil nw.]

49 minutes ago, Man With Beard said:

FV3 tonight - weakest vortex ever going into January!

30 and 100 hPa levels from nwextra

the SV being stretched almost to splitting at mid-level with the effects being felt at the lower level by day 15 on this run.

The 100hPa pattern pretty much reflected in the gefs mean 500hPa chart which should see further ridging in the Atlantic getting further north towards Greenland as the main pv transfers towards the Siberian side.

[Allseasons-Si]

At 30hpa

yesterday v today.

[JeffC]

Now is this the warming event the models were predicting because it's getting going at a pace now, - 10C @ 10hpa... 

This is over Russia, so is this as a result of an Asian Mountain Torque event? 

Edited December 22, 2018 by JeffC
Asking a question

[Interitus]

10 hours ago, Man With Beard said:

FV3 tonight - weakest vortex ever going into January!

Missed grabbing the data for this run unfortunately but subsequent run minimum u1060 were -2.1 and +4.6 m/s with the vortex reforming to +12 and +24.2 m/s by t384.

[Interitus]

1 hour ago, JeffC said:

Now is this the warming event the models were predicting because it's getting going at a pace now, - 10C @ 10hpa... 

This is over Russia, so is this as a result of an Asian Mountain Torque event? 

 

No 

[JeffC]

53 minutes ago, Interitus said:

No 

OK, what is the driver then?  

[Interitus]

16 minutes ago, JeffC said:

OK, what is the driver then?  

Differential planetary wave 1 forcing causing a westward tilt of the vortex with height creating a baroclinic region with descending air resulting in adiabatic warming (closer observation of the charts will also show that the area of lowest temperatures become cooler at the same time where air is ascending).

Edited December 22, 2018 by Interitus

[karyo]

The gfs operational doesn't look as good as yesterday with the split underwhelming and brief. The parallel is also underwhelming.

[ArHu3]

7 minutes ago, karyo said:

The gfs operational doesn't look as good as yesterday with the split underwhelming and brief. The parallel is also underwhelming.

EC ensemble mean was pretty confident of a split yesterday 

 

GEFS mean trending more towards a split too

 

Edited December 22, 2018 by ArHu3

[MattStoke]

I’d be more worried if it was the ECM backing off and being inconsistent with the strat warming. Supposedly it models these things better than the GFS.

[karyo]

I can't remember of another time that GFS and ECM were in so much disagreement at day 10. Tropospherically yes but not stratospherically. We need the GFS to come back on board.

[northwestsnow]

1 minute ago, karyo said:

I can't remember of another time that GFS and ECM were in so much disagreement at day 10. Tropospherically yes but not stratospherically. We need the GFS to come back on board.

Agreed K..

Always feel uneasy when there are conflicting signals..

Tis a shame we cant see Glosea5.

[ArHu3]

6 minutes ago, karyo said:

I can't remember of another time that GFS and ECM were in so much disagreement at day 10. Tropospherically yes but not stratospherically. We need the GFS to come back on board.

It's because we can only see the operationals, not the ensemble but look at Ventrice' tweets the splits are there

[karyo]

2 minutes ago, ArHu3 said:

It's because we can only see the operationals, not the ensemble but look at Ventrice' tweets the splits are there

True but those tweets are from yesterday when even the gfs operationals looked better. I hope the ensembles are still interested in the split.

[northwestsnow]

1 minute ago, karyo said:

True but those tweets are from yesterday when even the gfs operationals looked better. I hope the ensembles are still interested in the split.

Every run now takes on more importance , certainly as far as GFS is concerned.. i was dissappointed with the 00Z GFS runs strat wise..

Which model will blink 1st i wonder..

[JeffC]

1 hour ago, Interitus said:

Differential planetary wave 1 forcing causing a westward tilt of the vortex with height creating a baroclinic region with descending air resulting in adiabatic warming (closer observation of the charts will also show that the area of lowest temperatures become cooler at the same time where air is ascending).

Thanks, so is this the start of the SSW event then?

[phil nw.]

Latest(yesterday's)ECM data still with the reversal at the top around Christmas-in fact Christmas eve-at 1 hPa.

then it's a case of waiting for this to downwell to the lower levels.Currently we have a forecasted reversal at 10 hPa-60N properly underway around the 30th December

so a slight delay from the forecast a few days ago of around 3 days.

A look at the graph

 

shows the fall off in zonal winds down to almost 20 hPa level by year end.

As ever with these warmings there isn't a set timescale for the speed of the downwelling to the lowest levels of theStrat.and the subsequent effects to kick in at 500hPa .

It really is just a case of monitoring progress on these forecasts and hopefully get a quick tropospheric response.

[lorenzo]

Hopefully some PSC pics incoming in the next 24-48 hrs looking at the above temp profiles.

FV3 this morning not as progressive on the split as last evening's 12z.. Always caveat the GFS 06z run, i.e. don't trust it. Wonder if the FV3 will be subject to the same 'randomness'..

Couple of other plots below - Temp vs Pressure, the u wind profile and also Heat Flux progression.

Then from the excellent link shared earlier by I, a few from the NASA site.

GMAO still advertising a split vortex, GFS thinking not, GFS FV3 flipping between spilt / no split, ECM retaining the split vortex. A proper model conundrum here...

Over to Zacs site to see the latest view there from around 15:00 today. Updates circa 1000 Eastern which is 1500 for us in the UK.

 

Edited December 22, 2018 by lorenzo