Stratosphere Temperature Watch 2014/2015

[phil nw.]

Later GFS frames suggesting wave 1 vortex displacement towards the Atlantic side.

https://max.nwstatic.co.uk/gfsimages/gfs.20141113/12/360/npst30.png

It looks like we have a period of westerlies to get through before any further wave 2 activity could change things.

[Banbury]

'If' a SSW does occur what are peoples opinion of timescale of any cold hitting the UK?? I have heard different timescales mentioned .

 

Not sure then ?

[Mark Neal.]

Not sure then ?

Isn't there a lag of a few weeks generally from what I have gathered before the zonal winds change?! Could be wrong, I'm sure the knowledgable folk could help with this one.

Edited November 13, 2014 by Mark N

[shaky]

No updates this morning regarding the strat? Hmmm something might be afoot!! Hopefully continue with a strong warming and wave 2 attack when matt and the other guys update us! !

[kimb]

No updates this morning regarding the strat? Hmmm something might be afoot!! Hopefully continue with a strong warming and wave 2 attack when matt and the other guys update us! !

 

I think it was looking from the runs last night that a warming was less likely ?

[bluearmy]

Yesterday's run similar to the previous day.

[shaky]

Yesterday's run similar to the previous day.

well well thats a relief! !! Ecm not too bad aswell this morning! !

[Severe Siberian icy blast]

Guys without wanting to sound out of line here iv just read through the best part of a page of one liners and daft questions been asked taking Eds comments out of context a little bit . The strat thread is globally respected and used by people all over the world , so to protect its reputation can we not limit the updates to the ones who have made this topic so hot ? For me I look forward every morning to waking up and checking the update , and this morning woke up to clutter .

Sorry to sound a miserble git I'm not , I just don't want the good nature of the thread ruined .

Mods delete if feel the need

[picog]

Isn't there a lag of a few weeks generally from what I have gathered before the zonal winds change?! Could be wrong, I'm sure the knowledgable folk could help with this one.

I think the lag time is around 6 weeks.

[starstream]

Have to agree with SSI, and agree enough that I too will comment and not just 'like' the post. This is almost sacred ground,and there are question areas within the forum,and I doubt any of our members are precious enough to not answer,just keep the strat thread for Serious stuff.Even the Mod thread,as its quiet is getting silly one liners and opinions with no charts to back them up.

Edited as auto correct dislikes strat!

Edited November 14, 2014 by starstream

[snowking]

Well I'm not entirely sure why this place is as worried as it seems.

As BA points out the output is much the same as yesterday's, so concurrent Wave 1 and Wave 2 activity, wave two showing signs of waning just a little as we edge towards day 10.

In terms of the questions regarding a 'failure' etc etc - it depends what angle you are coming at it from. If you were expecting a full SSW then yes this impending warming phase will be a failure, and was always expected to be. I can't comment for others but my own expectations are of a far stronger warming occurring during December, timing of this is open to question right now. But to look at this from another point of view we should not view each warming that doesn't produce a cold spell as a failure. Each spell of warming, or wave activity, should be viewed as a little victory. Keep thinking along the lines of the boxing analogies that are plentiful within this thread. Unless it's a very big hit you are not likely to knock your opponent out straight away. So a bit like a boxing match between me and Mike Tyson, the only way I would beat him (and obviously I would beat him...) would be to wear him down over time, throw a few punches to the torso whenever possible. So each little warming and wave break we see, at this stage, is helping to tame the beast, it prevents the vortex from strengthening too much.

Will we see it strengthen any more than is is now? In the troposphere at least, almost undoubtedly, and this is well in line with expectations - think of it as Mike trying to take a bite out of my ear through the mid rounds. But this is expected and well in line with the work from Cohen et al.

The reason for Ed's comments were the same as everyone else's - the currently modelled split this time leaves too much energy around the Greenland area. That does not entirely prevent cold, but it does make it a lot less likely.

But I think the main issue so far has been everyone has been getting themselves a little too excited too early. I think everyone needs to take a step back, embrace the idea that from a stratospheric point of view this upcoming warming is fascinating for those of us who have frequented the thread over the years, but it is not likely to lead to a cold spell for the UK this time around.

The story after any potential december warming, should it occur and with the vortex leant against the ropes in the 12th round, may be very different.

SK

[Paul_1978]

Certainly a reality check there SK.

[bluearmy]

Great analogies there kris ( I think you would beat mike aswell. Corals have you at 6/4). I am interested by the persistance of the scandi ridge and it's feeding of trop waves into the lower strat. tbh, I just don't see it going anywhere anytime soon (that's a cue for it to suddenly disappear). I wouldn't discount a scandi high establishing in week 2 in tandem with a sharpening Atlantic trough.

[Recretos]

The story after any potential December warming, should it occur and with the vortex leant against the ropes in the 12th round, may be very different.

 

Something like that.

This current wave2 is welcome by all means. Any disruption no matter how small, is welcome. You cannot really expect an SSW split from the upcoming wave 2, it just doesn't work that way. But it has its role in whole picture.

 

Now what I expect in a relatively mid range:

As the W2 wanes, the W1 will remain present. I dont really expect it ever to completely back off this season (that would be a surprise). The vortex will reform some if not almost all of its composure, but the wave1 will hold it in a "not full strength" position, slightly dispositioned. With the natural flow of events i expect the vortex to eventually get back to disposition more over Scandi area or perhaps Siberia, which would be in time for  "wave's" 2 to to re-emerge as we head into December. So much for now.

[chionomaniac]

Well I'm not entirely sure why this place is as worried as it seems.

As BA points out the output is much the same as yesterday's, so concurrent Wave 1 and Wave 2 activity, wave two showing signs of waning just a little as we edge towards day 10.

In terms of the questions regarding a 'failure' etc etc - it depends what angle you are coming at it from. If you were expecting a full SSW then yes this impending warming phase will be a failure, and was always expected to be. I can't comment for others but my own expectations are of a far stronger warming occurring during December, timing of this is open to question right now. But to look at this from another point of view we should not view each warming that doesn't produce a cold spell as a failure. Each spell of warming, or wave activity, should be viewed as a little victory. Keep thinking along the lines of the boxing analogies that are plentiful within this thread. Unless it's a very big hit you are not likely to knock your opponent out straight away. So a bit like a boxing match between me and Mike Tyson, the only way I would beat him (and obviously I would beat him...) would be to wear him down over time, throw a few punches to the torso whenever possible. So each little warming and wave break we see, at this stage, is helping to tame the beast, it prevents the vortex from strengthening too much.

Will we see it strengthen any more than is is now? In the troposphere at least, almost undoubtedly, and this is well in line with expectations - think of it as Mike trying to take a bite out of my ear through the mid rounds. But this is expected and well in line with the work from Cohen et al.

The reason for Ed's comments were the same as everyone else's - the currently modelled split this time leaves too much energy around the Greenland area. That does not entirely prevent cold, but it does make it a lot less likely.

But I think the main issue so far has been everyone has been getting themselves a little too excited too early. I think everyone needs to take a step back, embrace the idea that from a stratospheric point of view this upcoming warming is fascinating for those of us who have frequented the thread over the years, but it is not likely to lead to a cold spell for the UK this time around.

The story after any potential december warming, should it occur and with the vortex leant against the ropes in the 12th round, may be very different.

SK

My thoughts exactly Kris. We needed the wave 2 to break from Greenland not Scandi to reap maximum benefits. Plenty of chances further down the line especially when we are in winter when benefits will be greater!

[sebastiaan1973]

http://web.mit.edu/jlcohen/www/papers/Cohenetal_GRL10.pdf

 

Has someone the SLP and WAFz, so we can compare 2009 with 2014. Thanks!

[Nouska]

http://web.mit.edu/jlcohen/www/papers/Cohenetal_GRL10.pdf

 

Has someone the SLP and WAFz, so we can compare 2009 with 2014. Thanks!

 

The SLP was a good match in October but has gone out of step in the first trimester of November. You can do a quick compare of other levels on the JMA link where I've used the ten day increments.

 

 

 

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/figures/db_hist_jun_tcc.html

[Recretos]

Too bad I dont have enough time to make full plots of the Para GFS 12z, but it is enough to just say that despite it looking horrible for the trop, in the upper parts of the strat it starts a wave 3 assault on the vortex in the final FI parts.  Pacific W1, Atlantic W2 and Indian W3.

 

Edit:

Oh what the hell,... Dont have the time to edit text stuff, so just for the record until the new run removes it (or not). This is 10mb 384h forecast of the parallel 12 GFS. This could be a start of a good story if it would be to materialise. Oh well, the darn FI,... Pretty much the most defined wave 3 pattern example you can find far around.

 

Edited November 14, 2014 by Recretos

[KyleHenry]

Too bad I dont have enough time to make full plots of the Para GFS 12z, but it is enough to just say that despite it looking horrible for the trop, in the upper parts of the strat it starts a wave 3 assault on the vortex in the final FI parts. Pacific W1, Atlantic W2 and Indian W3.

Edit:

Oh what the hell,... Dont have the time to edit text stuff, so just for the record until the new run removes it (or not). This is 10mb 384h forecast of the parallel 12 GFS. This could be a start of a good story if it would be to materialise. Oh well, the darn FI,... Pretty much the most defined wave 3 pattern example you can find far around.

When the time comes regarding wave 3, how much fun are you going to have working out the displacements.

It's a nice three step walloping, what the end result is for the location and form of the PV/ lobes of PV will be, is the best part

Edited November 14, 2014 by KyleHenry

[USWX23]

Hey all, first post from across the pond... The tropospheric pattern causing a split in the short term is sending plenty of early season cold over here the next 10 days. Thanks once again to our -EPO regime..The Plains had some record shattering cold the last few days. Denver, CO just east of the Rocky mountain line dropped to -14F, the 2nd coldest November reading on record to -18F on Novy 29th, 1877.  Astounding stat there given climo...Seems like you folks will have to wait until the bigger shakeup of the vortex occurs as it seems to want to settle over Greenland. The wave activity is fantastic though early on.

 

Here are some strat images for you courtesy of the EPS from last night.

 

 

Looks like secondary warming forming out of Europe late in the 11-15 day

Edited November 14, 2014 by USWX23

[chionomaniac]

Hey all, first post from across the pond... The tropospheric pattern causing a split in the short term is sending plenty of early season cold over here the next 10 days. Thanks once again to our -EPO regime..The Plains had some record shattering cold the last few days. Denver, CO just east of the Rocky mountain line dropped to -14F, the 2nd coldest November reading on record to -18F on Novy 29th, 1877.  Astounding stat there given climo...Seems like you folks will have to wait until the bigger shakeup of the vortex occurs as it seems to want to settle over Greenland. The wave activity is fantastic though early on.

 

Here are some strat images for you courtesy of the EPS from last night.

 

11-14 strat forecasts.PNG

 

Looks like secondary warming forming out of Europe late in the 11-15 day

Hi USWX23 and welcome to the forum. Always great to have input from overseas mets.

 

Thanks for the ECM strat ens images

Interesting that the wave 2 warming is so pronounced post day 10 - it was suggested by the Berlin charts this morning. Strange that I looked at quite a few GFS runs earlier today and no significant dual warming seemed to be modeled post day 10.

 

If the wave 2 is prolonged enough then we may benefit this side of the Atlantic - but by that time the US may be sick of a cold pattern, 'cos it would have to hang around  for a very long time!

[chionomaniac]

http://web.mit.edu/jlcohen/www/papers/CohenandJones_JC12.pdf

 

Well SWesterlies is just what we see 14-7 days before a SSW, according to this research by Judah Cohen. It all suits right well. High pressure in eastern Europe, low pressure near Alaska. So tropospherically  we can expect a slowly retreating Russian high to the east and  from a negative AO to a positive AO.

Hi sebastiaan. I meant to say but forgot after seeing this post that we would see a positive NAO following the increase in WAF and a similar trop pattern regardless of whether we achieved an SSW or not, it was just that this time I thought that the forecast warming and split would not lead to an early SSW. I still favour that later in the season.

[chionomaniac]

Just to add that it appears that the Wave Activity Flux is forecast to drop off again by the end of the month. The Siberian high will need to reform over a more favourable location for this to increase again.

 

One can see that looking at the 11-15 day NAEFS that the negative height anomaly over Siberia precludes any favourable WAF.

 

 

The latest AER blog reduces the likelihood of an early SSW as a result.

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

[bluearmy]

As you were on the Berlin update. The upper reaches of the strat are not a welcoming place for the vortex over the next two weeks. wave 1 continues and wave 2 strengthens. Zonal flow at the top drops - at the moment, the flow > 50m/s covers 38 degrees of lattitude. In ten days, that is below 10%!!!!

Polar strat temps beginning to show their uptick on the graph, though temps in the displaced vortex remain typical for the time of year. The point as made by the knowledgable on here is that once there is a recovery in the strat vortex (as surely there must be in December), it will have lost almost a month of favourable conditions to establish itself and if we do see the expected onslaught of wave activity in December, it will not be the monster that stood up to any barrage last year and failed to fall. It should give way quite quickly. Then, it becomes a roll of the dice to see where the residual chunks of trop vortex settle.

Edited November 15, 2014 by bluearmy

[Duane S.]

BA describes the net effect of these moderate warnings and wave breaks very well ^^^

This is the time of year when the stratosphere is naturally cooling and a single vortex grows in intensity and becomes more compact. To me these moderate warming etc are as important (maybe even more so) as a full on SSW type later on in the winter. Stopping the vortex getting to its dominant and inpenitrable stage through its natural maturity period leaves it weaker at the core and far more suscepitible thereafter.

Of course there always lies the possibility of deep Strat cooling period later on but with us in a strong easterly QBO phase I would fancy our chances of having a winter full of "guess where the pieces of vortex/energy are going to end up". This is what makes winter 14/15 a completely different entity to 13/14.

I did notice yesterday's ECM had the lowest zonal wind speed forecast yet at 10mb/60n, still a way off reversing and probably unlikely to but as above, it all helps!