Stratosphere temperature watch - 2016/17

[Man With Beard]

51 minutes ago, Summer Sun said:

 

Can someone clever help me here. Sometimes I get the feeling in this strat thread that it's all or nothing. I.E. If we get a reversal of -1m/s, we could get a huge hemispherical change. But if the 10hpa 60N zonal wind stays just above e.g. +1m/s, nothing will get achieved.

That's just the way it comes across sometimes. Is that really black and white like that? Or are the consequences more proportional in line with the speed? (In which case, who would be bothered whether the wind speed is +1 or -1?)

Edited January 27, 2017 by Man With Beard

[danthetan]

15 minutes ago, Man With Beard said:

Can someone clever help me here. Sometimes I get the feeling in this strat thread that it's all or nothing. I.E. If we get a reversal of -1m/s, we could get a huge hemispherical change. But if the 10hpa 60N zonal wind stays just above e.g. +1m/s, nothing will get achieved.

That's just the way it comes across sometimes. Is that really black and white like that? Or are the consequences more proportional in line with the speed? (In which case, who would be bothered whether the wind speed is +1C or -1C?)

Just to point out that tweet was from yesterday so things may have changed by today's update. 

[chris55]

4 minutes ago, Man With Beard said:

Can someone clever help me here. Sometimes I get the feeling in this strat thread that it's all or nothing. I.E. If we get a reversal of -1m/s, we could get a huge hemispherical change. But if the 10hpa 60N zonal wind stays just above e.g. +1m/s, nothing will get achieved.

That's just the way it comes across sometimes. Is that really black and white like that? Or are the consequences more proportional in line with the speed? (In which case, who would be bothered whether the wind speed is +1C or -1C?)

I thinks its just terminology to be honest +1/-1doesnt really make any difference to the Strat pattern as a whole

 

5 minutes ago, danthetan said:

Just to point out that tweet was from yesterday so things may have changed by today's update. 

Strat zonal winds are marginally slower in today's update, also the additional warming signal is still there.

[danthetan]

6 minutes ago, chris55 said:

I thinks its just terminology to be honest +1/-1doesnt really make any difference to the Strat pattern as a whole

 

Strat zonal winds are marginally slower in today's update, also the additional warming signal is still there.

Looking at the date are  those yesterdays charts Chris? 

[chris55]

2 minutes ago, danthetan said:

Looking at the date are  those yesterdays charts Chris? 

Yes these chart update the following day on the Berlin site.

[feb1991blizzard]

Its more important where the Ridge / vortex or vortices position themselves after the warming, On that 192 chart, if there wasn't another warming immanent, the vortex would quickly move back over the pole, I'm guessing here but probably with negligible effect on the troposphere.

[bluearmy]

I have been saying that a weak reversal isn't any much better than a weak strat 

and how far down does any strong reversal get and at what latitude is it ??

And then you get to propogation 

far too complicated to say A + B = C but twitter doesn't allow for deep and detailed  discussion 

[Nouska]

55 minutes ago, feb1991blizzard said:

Its more important where the Ridge / vortex or vortices position themselves after the warming, On that 192 chart, if there wasn't another warming immanent, the vortex would quickly move back over the pole, I'm guessing here but probably with negligible effect on the troposphere.

Agreed - just as an example, I'll include the SSW reanalysis charts for 2006 that I posted in the winter thread.

pre 2006 SSW - almost identical to the current displacement.

Afterwards the vortex moved over the Eurasian land mass and led to a colder pattern for the UK. This is the type of response Cohen is looking for in his recent report and what @Singularity was describing, either here or in the model thread.

I'm not seeing that yet as the tendency this time is to want to move back polewards after each wave of warming. The QBO was east phase back in 2006 - the fact we are in a strongly west phase may be what is preventing the final push.

2 minutes ago, booferking said:

Does the 06z get us any closer to 2006?

Looking at the temperature chart does not help here - need to look at the geopotential heights charts that go with it.

http://www.instantweathermaps.com/GFS-php/strat.php

Edited January 27, 2017 by Nouska

[feb1991blizzard]

3 minutes ago, Nouska said:

 

I'm not seeing that yet as the tendency this time is to want to move back polewards after each wave of warming. The QBO was east phase back in 2006 - the fact we are in a strongly west phase may be what is preventing the final push.

I thought at the time that QBO anomaly happening a good few months back could be the one thing that scuppers a cold winter, people said it wasn't important but there was a chart with solar / qbo combinations somewhere on last years thread and it does reduce the chances, the other thing I overlooked with my early thoughts on winter, is that although we have low solar activity, it is not technically a solar minimum, Not sure if theres a lag effect with that as I don't really know anything about solar activity but I get the feeling if we had hit solar minimum and that QBO would have been East, coupled with the fact that regardless of those 2 factors we have still been close with some MLB blocks - ( 'the nearly pattern', ), then we would have been looking at a fairly spectacular and protracted winter.

[booferking]

12 minutes ago, Nouska said:

Agreed - just as an example, I'll include the SSW reanalysis charts for 2006 that I posted in the winter thread.

pre 2006 SSW - almost identical to the current displacement.

Afterwards the vortex moved over the Eurasian land mass and led to a colder pattern for the UK. This is the type of response Cohen is looking for in his recent report and what @Singularity was describing, either here or in the model thread.

I'm not seeing that yet as the tendency this time is to want to move back polewards after each wave of warming. The QBO was east phase back in 2006 - the fact we are in a strongly west phase may be what is preventing the final push.

Does the 06z get us any closer to 2006?

[bluearmy]

3 minutes ago, booferking said:

Does the 06z get us any closer to 2006?

Be careful using just temps I/o heights and temp anomolies  - they don't generally correlate 

i would be looking for a trop wave 2 pattern (sceuro and aleutian ridges) which could work up and split the vortex that remains. Without that I think it's a struggle to see anything significant resulting from this displacement 

Edited January 27, 2017 by bluearmy

[booferking]

Just now, bluearmy said:

Be careful using just temps I/o heights and temp anomolies  - they don't generally correlate 

Ok thanks  got it i take take it heights anomolies charts are not free are accessible for gfs?

[chris55]

23 minutes ago, booferking said:

Ok thanks  got it i take take it heights anomolies charts are not free are accessible for gfs?

 GFS strat data here http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/

[booferking]

13 minutes ago, chris55 said:

 GFS strat data here http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/

Cheers.

[Singularity]

There are signs of Aleutian height rises in the longer-range output, but at the same time the models keep eroding the Sceuro heights. 

The tendency for the latter not to give way so easily may cause frustrations in terms of keeping storms more to the W/NW but it would perhaps raise the scope for a wave-2 warming. What's the chances that early-mid Feb is the first fortnight this season in which this tendency does not materialise? 

It may come down to the MJO after all, as a 4-5-6 via kicking GLAAM upward etc. could potentially help both the Aleutian and Sceuro height rises out - hence I will continue to chase after it, as it seems like our only true hope now. ECM is not yet definitive enough with the signal to raise expectations, as the most recent EC42 made all too clear (but I wonder what the spread of outcomes contained).

[Summer Sun]

 

[mountain shadow]

14 minutes ago, Summer Sun said:

 

So the clock is ticking to when we see a Trop response, the outer range of the GFS may now start to show some interest.

[Ruben Amsterdam]

First nacreous clouds spotted near Tromsø, Norway. Very spectacular sunset here in Oslo yesterday, also due to the cold stratosphere (although I personally did not observe any "classic" pearly clouds). All signs that the vortex is indeed displaced. 

Picture source is the twitter account of Yr.no, a collaboration between the Meteorlogical Institute and state broadcast NRK. 

 

Edit: picture I took from the sunset here yesterday

Edited January 27, 2017 by Ruben Amsterdam

[Nouska]

1 minute ago, Ruben Amsterdam said:

First nacreous clouds spotted near Tromsø, Norway. Very spectacular sunset here in Oslo, also due to the cold stratosphere (allthough I personally did not observe any "classic" pearly clouds. All signs that the vortex is indeed displaced.

Thanks Ruben.

The forecast penetration of a very cold strat over the UK was overdone on the first phase but looking better for the weekend with -84C overhead - should verify at such close range. Question - will there be clear enough skies to view and are there other missing factors to consider in the formation of nacreous clouds?

[JeffC]

here it is again - really easy to visualise on this what's going on at 10 hPa, especially if you click on a point and get the spot temp.

warmest I could find was -8.9 against -80 at coldest.

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-13.19,93.29,255/loc=69.726,57.984

fascinating stuff

[chris55]

47 minutes ago, JeffC said:

here it is again - really easy to visualise on this what's going on at 10 hPa, especially if you click on a point and get the spot temp.

warmest I could find was -8.9 against -80 at coldest.

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-13.19,93.29,255/loc=69.726,57.984

fascinating stuff

That's mesmerising, its a cool little tool to help picture the atmosphere in action. 

[JeffC]

3 hours ago, chris55 said:

That's mesmerising, its a cool little tool to help picture the atmosphere in action. 

yes, brilliant for folk like me who struggle to visualise some of the model outputs, there it is all simple like!

[ArHu3]

5 hours ago, JeffC said:

here it is again - really easy to visualise on this what's going on at 10 hPa, especially if you click on a point and get the spot temp.

warmest I could find was -8.9 against -80 at coldest.

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-13.19,93.29,255/loc=69.726,57.984

fascinating stuff

how did the southern hemisphere end up with all easterlies!?

[JeffC]

1 hour ago, ArHu3 said:

how did the southern hemisphere end up with all easterlies!?

only at 10 hPa, lower down is more conventional flow... click on "earth" and you can alter the parameters and metrics.

assume it's something to do with it being southern hemisphere ?

 

 

[JeffC]

14 minutes ago, JeffC said:

only at 10 hPa, lower down is more conventional flow... click on "earth" and you can alter the parameters and metrics.

assume it's something to do with it being southern hemisphere ?

 

 

in fact see this link - shows how it works... look at the flow in the different hemispheres - it reverses on the equator!

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-34.68,-1.31,255/loc=-26.717,-0.805

 

 

Edited January 27, 2017 by JeffC