Stratosphere Temperature Watch 2014/2015

[bluearmy]

ed, can you have a look at the momentum flux wave 2 charts from the latter part of yesterdays ecm run. i cant ever recall seeing a profile like that low down ?

 

also, that run introduced significant wave 2 effect right up to the mid strat (upwelling) and the wave 2 temp profile reflects that and does show some small wave 2 activity high up. it seems that the effects of this current warming and trop led wave breaking will show themselves in the upper strat in the 14-21 day period. given that the trop profile continues to look amplified, the vortex may not get much respite throughout november. will be interesting to see what transpires between 10 and 30hpa in the final third of november re temps, zonal flow and heights

[MattH]

Morning all, few features of interest this morning, clearly only 12 hours or so ago since yesterday evening's discussion but following on from the ECM ENS temp anom charts is yesterday's 12Z ECM data from the Berlin site and whilst not ignoring the continued wave 1 activity, which ties in nicely with the the deep low over near Alaska, there are potential signs of ridging and a split (wave 2 activity) near Greenland. By the way anyone wanting to try and get their head around wave 1 and wave 2 activity then definitely read the post above from Ed, a rather majestic way of describing it and, in a nutshell, it really is like 'water'...

 

Charts of interest this morning that stand out to me;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf70f216.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf70f240.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf50f240.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf30f240.gif

 

Signs of a split from bottom upwards. Clearly the vortex becomes increasingly elongted towards 192hrs or so and especially at the bottom end of the strat it splits with possible ridging near Greenland and this may well be tied in with the model attempting to pick up on wave 2 activity now. Even at 30hpa there has been a sudden increase in elongated shape to the vortex and it almost splits at 30hpa (on the last link above) by 240hrs. Interestingly there is cross-model agreement with the 00Z GFS also signalling this process...

 

https://max.nwstatic.co.uk/gfsimages/gfs.20141108/00/216/npst30.png

https://max.nwstatic.co.uk/gfsimages/gfs.20141108/00/288/npst30.png

 

The signal for wave 2 activity has definitely increased as well if you look at the ZMS charts in terms of wave 2. Whilst still not reaching any significant values, towards the end of the run the wave 2 signal does extend through a large portion of the strat...

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha2&lng=eng#fig11

 

The subsequent increase in wave 2 temps is in evidence as well;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta2_f240.gif

 

It's certainly interesting developments and again when combined with the ECM EPS charts that I posted last night begins to build up a bigger picture that maybe there is the threat of an upwelling event around Greenland within the 7 to 10 day time frame, with a possible split from the bottom up. Equally the signal for warming from the top down is still there as well, as per the following images.

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf5f240.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta1_f240.gif

 

A potentially bold statement coming up but even if the vortex splits this early in the season and attempts to reform in time, I think given the overal background state of the conditions this winter, as discussed many times now (-ve QBO, SAI etc etc) I think there would still be further opportunities down the line, through the winter, for further significant wave 1/2 events to take place as well.

 

Also of interest is the 00Z ECM - http://www.wetterzentrale.de/pics/Recm2401.gif - Now if that's not a tropospheric 'brick' in the water then I don't know what is!

 

Let the 'fun and games' continue to develop!

 

Matt.

[EML Network]

This thread has been absolutely great to review, read and learn from. 

 

My hats go off to the several regular posters on this thread for taking the time to explain things in such a manner that one can actually visualize it and make sense of it and to all those who take the time to explain what is happening right now and how that might effect the weather we see here on the ground. 

 

I for one think that we will be very unlucky to get to Xmas without having experienced at least one decent cold spell and I'm confident most of us will see snow falling before the year is out. 

 

A far cry from this time last year and I'm amazed that the seasonal models are doggedly sticking to their guns, indicating a repeat of last year.

 

A bit off topic, but I just wanted to voice my thanks to all the hard work that goes into this thread.  

Edited November 8, 2014 by EML Network

[feb1991blizzard]

If the ECM 0z day 10 chart is repeated on the 12z then tomorrows zonal wind chart will be interesting!!!.

 

Todays is none to shabby.

 

 

[lorenzo]

Running through the Berlin charts this morning is akin to watching a boxing match. The vortex getting a monster elongated uppercut from Alaska, wobbling onto it's back foot in Siberia, trying to regain balance (shape) then a few days later receiving another left and a right as Wave 1 moves to Wave 1 and 2. Pretty spectacular stuff. Missed the boat on the great charts already up for ECM so here are a few more to give another view.

 

Time series of sustained attack on vortex via JMA and also the GPH anomalies for OND to date.

 

 

Link to time series is here  http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/  You now have to manually edit the dates to see some of the historic ones, this year is live on main page.

 

 

ECM and what will it do next, one of the peak AO runs of the season so far, given the previous 50hPa split near end of October, posted last night, and that mean set up, come to the conclusion that I am loving this eQBO so far this season !

 

Re - momentum flux chart BA, not seen anything like this one either, sorry, can't help further, I need guidance reading these. Could do with some annotation.

 

Exciting times, and a complete pleasure to look through output this year versus last years bleary eyed, relentlessly frustrating output!

Edited November 8, 2014 by lorenzo

[Frozen Britain]

Any wave 2 forecast activity at present is weak and limited to the troposphere. Just to recap, in an uninhibited system the polar vortex would form over the north pole every winter and be perfectly cylindrical every winter from the troposphere to the top of the stratosphere. In reality this is not the case and near the tropospheric surface slight undulations occur at the boundary of the vortex. However for a wave pattern to form these undulations have to be of a significant size and amplitude.

 

Imagine having a circular bath with a plug in the middle. Once this plug is pulled out the water will flow out in a circular motion with the plug hole being the centre of the vortex. If I was then to insert a brick into the bath towards the edge of the vortex then the flow would be disrupted significantly and diverted around the brick - we would have created a situation where a wave is created around the flow. If we were then to insert another brick in the bath then we would create two waves disrupting the flow. The first scenario we call a wave number 1 and the second a wave number 2. The size and position of the brick(s) would significantly detemine how the vortex would flow. And so we can consider the same with the stratospheric/tropospheric vortices. 

 

So back to the original question, currently we are seeing strong wave 1 activity at the top of the stratosphere ( explanation of how this occurs is in the first post - external upwelling around the surf zone of the vortex, then downwelling from the top of the strat). If this wave activity is strong enough the whole vortex can be weakened. Sometimes and more critically the already weakened vortex is prone to an internal upwelling wave break - but the position and timing and strength of this wave break is critical. If everything is timed perfectly then the wave can break into the centre of the vortex from below and split it - a rare upwelling - but the nirvana situation if everything falls in place.

 

And here is a classic example of a wavenumber 2 tropospheric led internal upwelling wave break right into the heart of the middle stratosphere creating a split vortex towards the upper strat. Waves are highlighted.

 

 

archivesnh-2009-12-13-0-0.png

 

I think that there is a very small chance that we could see something similar this year for late autumn/early winter, but I favour a more traditional over the top type of Canadian warming being forecast from the top of the strat downwards. Both are not mutually exclusive. Last year I would say there was no chance of this type of split, so a small chance is better than none.

Excellent post. So it is a case of watch and wait then? And at the moment, that scenario seems unlikely soon?

[Cloud 10]

Some great posts in here this morning.

 

Loving all these split vortex shenanigans.

 

[Duane S.]

Not much to post after Matt's and Lorenzo's excellent summings up above!

 

The wave2 forecast charts have an interesting look to them, still fairly low in strength but predominately trop led. I can only see this becoming more amplified over the coming days/weeks

 

The AO scale had to be altered back in winter 09/10 (from -4 down to -6), I get the distinct impression that extended scale will be needed again this winter!

 

Last year it was all about grasping at straws, this year I think it will be case of when, not if...

[ITSY]

Just to say thanks to chino for that response. Understand most of it and I looks like we could be on the cusp of something. Super thread this is - I wonder if the pros use it!

[Catacol]

Met Office long rang up to 30 day still ignoring any sense of a change in the pattern. Strikes me as a bit odd as these strat forecasts are starting to show up on the trop models for the second half of the month. Little bit surprising that the text of their forecast doesnt even suggest the possibility of more northern blocking and a shift in the pattern direction.

[bluearmy]

Met Office long rang up to 30 day still ignoring any sense of a change in the pattern. Strikes me as a bit odd as these strat forecasts are starting to show up on the trop models for the second half of the month. Little bit surprising that the text of their forecast doesnt even suggest the possibility of more northern blocking and a shift in the pattern direction.

 

if their strat model isnt showing anything that will have ramifications for nw europe then they wont mention any caveats.

[feb1991blizzard]

if their strat model isnt showing anything that will have ramifications for nw europe then they wont mention any caveats.

 

I cant believe there wouldn't at least be some cold long range solutions amongst the ensemble spread of solutions on offer, the GLOSEA5 run is due in the next week I think anyway, mind you they didn't mention anything cold for Nov 2010 until 5th Nov, I cant think that it didn't even warrant consideration before that date.

[karyo]

Both the 0z GFS and the 6z have upgraded the warming and they split the vortex. The 6z is probably the best of the season so far with some oranges appearing at the 30hpa level.

 

As for the Met Office, I wouldn't worry. They are usually the last to mention anything in their updates and they are happier when the weather comes from the Atlantic which doesn't test their forecasting skills.

 

Karyo

[Don]

I cant believe there wouldn't at least be some cold long range solutions amongst the ensemble spread of solutions on offer, the GLOSEA5 run is due in the next week I think anyway, mind you they didn't mention anything cold for Nov 2010 until 5th Nov, I cant think that it didn't even warrant consideration before that date.

 

They probably are considering some colder options, but at this stage, they probably don't have enough confidence to see them as the most likely outcome, so won't mention anything just yet?

Edited November 8, 2014 by Don

[feb1991blizzard]

They probably are considering some colder options, but at this stage, they probably don't have enough confidence to see them as the most likely outcome, so won't mention anything just yet?

 

Yes because there are no doubts these stratospheric conditions (and trop interactions) will be showing up on all models to varying degrees for sure, as pointed out, its a matter of if we end up with trop conditions favourable for a continental feed into Britain and whether any cold pooling is potent enough.

[bluearmy]

The 06z is the most progressive run I've seen in week 2 and splits the vortex way up to 5mb

Note that the Alaskan ridge becomes an Aleutian one in tandem with wave 2 via this and the ridge from our side of the pole.

[Chris K]

Both the 0z GFS and the 6z have upgraded the warming and they split the vortex. The 6z is probably the best of the season so far with some oranges appearing at the 30hpa level.

 

As for the Met Office, I wouldn't worry. They are usually the last to mention anything in their updates and they are happier when the weather comes from the Atlantic which doesn't test their forecasting skills.

 

Karyo

 

Atlantic weather still tests any forecaster, even if it is where our prevailing weather comes from. The bands of today's rain were still causing some headaches just last night, with regards to the timing of arrival for certain areas.

 

Anyway - I would have thought they would prefer to talk about the current, more reliable output rather than base it on some signals of cold which may or may not come to fruition. They may indeed be seeing some signals and internally discussing that, but in all honesty, even though the NH profile is looking great for a potential cold pattern down the line, the UK is still stuck in a cool, unsettled regime for the foreseeable.

Edited November 8, 2014 by Chris K

[chionomaniac]

Please keep this thread on topic and don't be surprised if the off topic comments go missing. Thanks

[Cakie]

Guys, try to think before posting. We don't need to get personal, thanks

[summer blizzard]

Met Office long rang up to 30 day still ignoring any sense of a change in the pattern. Strikes me as a bit odd as these strat forecasts are starting to show up on the trop models for the second half of the month. Little bit surprising that the text of their forecast doesnt even suggest the possibility of more northern blocking and a shift in the pattern direction.

 

32 day Met Office forecasts are largely based from the 32 day ECWMF run.

[Bullseye]

I have bookmarked this topic on phone and reading daily, must admit has helped me gather some understanding and importance to winter so thank you to everyone for that! One question I have been meaning to ask and that is, with wave 2 activity now being forecasted which by my gathering is good thing for us (W.Europe) but isn't there a fear of this activity being forecasted so early in winter a fear for rest of winter like PV being able to gather formation again few months down the line? Cheers and sorry if its not explained well.

[phil nw.]

Come on people many of the last few posts have nothing to do with the Stratosphere!

Let's get back on topic now please.

Ta.

[snowking]

Just seen this posted by Michael Ventrice over on twitter from the 0z ECM ensemble mean:

 

 

Split up to 50mb with a ridge around the Greenland vicinity, apparently elongated as far up as 10mb but no split above this level just yet. Bear in mind that chart is an ensemble mean, and things start to look positive. And that's before the strongest of the warming towards Asia has appeared...

 

SK

[MattH]

Eerrrrrr.... Bank! http://www.wetterzentrale.de/pics/Recm2161.gif - implications not only in the troposphere but the stratosphere too. Surely an outlier though.

Have a feeling we are on the cusp of something or nothing for the time being. Very early in the season so even if this doesn't come off there is plenty of time this winter. If it does come off and this pattern aids a wave 2 split then some early/very early cold weather is increasingly likely.

Those Berlin charts will be interesting later!

Matt

[Cloud 10]

I look forward to tomorrows ECM strat charts.

 

 

^^^^^^

lol,Matt.

Edited November 8, 2014 by Cloud 10