Stratosphere Temperature Watch 2014/2015

[Duane S.]

I was going to big up yesterday's ECM strat charts but I can't follow those excellent summaries by Matt and Lorenzo!

Other than highlighting my 2 favourite charts of the run...

Not far off a technical SSW (day 7-9 actually closer but this is better in terms of the whole column reversing, albeit too far north for an SSW)

Strongest yet

I note today's 00z ECM op is interesting and whilst it has the distinct look of another attempted mid Atlantic ridge that will topple, I'm not so sure it will be that clear cut with what is going on up above, yet.

Edited December 28, 2014 by s4lancia

[Cloud 10]

The changes in the strat output have been well picked up on in the posts above,but just wanted to highlight the dramatic difference between the last two runs at 10 hpa for the 5th of January.

 

26th..  27th..

 

Not used to seeing that sort of change in the strat output.

[Severe Siberian icy blast]

I think it's only a matter of time now before we see some HLB Over our side of the pole , with the vortex taking such a battering over the next 10 days especially with the warmings forecast to develop more over the Greenland area really may well open the door to opportunities down the line for us.

I can't help feeling that Matt should of stuck to his original prediction of a SSW on the 5th jan ! Beofre he retracted this prediction that is !

[bluearmy]

just to say that the split at 30 and 10 hpa on the day 10 ecm 00z run closes up as gfs has consistently shown. whilst there remains a strong ridge from the north pacific at that time, it seems clear to me that the gfs strat modelling is quite reliable days 10/12.

 

we could really have done with another day or so of decent wave 2 strength and we would have cracked it. i guess the lesson will be the that next cycle will probably do the trick and we may not have to wait too long for it.

 

anyone else notice the very close relationship between trop and strat that currently exists ? barely a day or two between strat and trop showing the same pattern. the downwelling is clearly very efficient which is again, a good sign should we see a sustained reversal of zonal flow at a slightly lower latitude. maybe we wont have to wait for the standard potential quick response followed by a couple of weeks before the reversal downwells.

[Duane S.]

just to say that the split at 30 and 10 hpa on the day 10 ecm 00z run closes up as gfs has consistently shown. whilst there remains a strong ridge from the north pacific at that time, it seems clear to me that the gfs strat modelling is quite reliable days 10/12.

 

we could really have done with another day or so of decent wave 2 strength and we would have cracked it. i guess the lesson will be the that next cycle will probably do the trick and we may not have to wait too long for it.

 

anyone else notice the very close relationship between trop and strat that currently exists ? barely a day or two between strat and trop showing the same pattern. the downwelling is clearly very efficient which is again, a good sign should we see a sustained reversal of zonal flow at a slightly lower latitude. maybe we wont have to wait for the standard potential quick response followed by a couple of weeks before the reversal downwells.

Yes, I'd noticed there seems to be a relatively short lag, presumably having a strong E-QBO helps a bit in that respect.

Wave2 is interesting though. The forecasts are continually pepping it up in strength and whilst it does wane quite quickly, this may still change. And even if not you can't help but think a much bigger wave2 event is waiting in the wings to bulldoze in very shortly afterwards.

[Interitus]

We may be seeing two things at play. First the initial split feeds upwards from lower levels in response to the troposphere - here are some of the times the GFS 28/12 00z shows a split in geopotential heights -

100mb 99-216 hours

70mb 99-228

50mb 96-240

30mb 99-228

20mb 102-228

10mb 114-264

7mb 120-264

5mb 123-264

3mb 132-276

2mb 144-276

1mb 150-276

 

As alluded to in above posts, yesterday's ECM also hints at the vortex reforming at lower levels later on but is showing a greater split higher up. This is also shown in yesterday's GEOS plots from the same time, particularly interesting are the 1800K isentrope vorticity and 1mb temperature animations at the end of which may be indicative of an actual warming induced split which will work it's way down.

http://acdb-ext.gsfc.nasa.gov/Data_services/arctic/anim_EPV_1800.html

http://acdb-ext.gsfc.nasa.gov/Data_services/arctic/anim_T_0001.html

 

Today's charts may provide some clarity on this... or they may not (lol).

Edited December 28, 2014 by Interitus

[ItNeverSnowsInWindsor]

Is there any chance all this stratosphere warming could override the Westerly pattern were stuck in.

[Catacol]

Is there any chance all this stratosphere warming could override the Westerly pattern were stuck in.

 

Right now the pattern is relatively blocked. Mobility will return in a few days time. Yes a SSW can/will interrupt this but probably not until we get some of the warming centred over Greenland. The immediate wave 1 assault is driving vortex energy into the atlantic and the siberian high remains strangely muted.... hence why our current high is sinking. But warming over Greenland should help disrupt the flow and allow heights to rise to our north. For me I have a small bet on January week 2 seeing a return of higher pressure - though I must admit the latest JMA monthly anomaly charts are not encouraging. 

 

What has surprised me a lot this winter so far has been the weakness of the siberian high especially given the early boost it must have been given by snow cover. I have not seen anyone explain this yet - even Cohen wrote as though he was puzzled by the siberian pattern - and the impact of this has been to promote atlantic mobility even though the vortex was given a good bashing in November. Frustrating.

[MattH]

Right now the pattern is relatively blocked. Mobility will return in a few days time. Yes a SSW can/will interrupt this but probably not until we get some of the warming centred over Greenland. The immediate wave 1 assault is driving vortex energy into the atlantic and the siberian high remains strangely muted.... hence why our current high is sinking. But warming over Greenland should help disrupt the flow and allow heights to rise to our north. For me I have a small bet on January week 2 seeing a return of higher pressure - though I must admit the latest JMA monthly anomaly charts are not encouraging. 

 

What has surprised me a lot this winter so far has been the weakness of the siberian high especially given the early boost it must have been given by snow cover. I have not seen anyone explain this yet - even Cohen wrote as though he was puzzled by the siberian pattern - and the impact of this has been to promote atlantic mobility even though the vortex was given a good bashing in November. Frustrating.

 

Just touching on this, perhaps not directly strat related as such, but whilst there is a lot of winter left (and under the right synoptics at least the first half of March) the background 'signs and signals' have yet to come good. I think many people on internet forums, away from the professional side of things, have been bombared earlier this autumn and into early winter with the likes of the OPI which, despite various disclaimers from some, may well have left a lot of people thinking the majority of the winter would end up blocked and the UK to be bombared with E or NE'lies for weeks at a time, for example. The OPI, whilst for another discussion, is just one variable amongst many but it may well have been taken on board too much I feel in previous months now that a significant 'spot light' has been shone on to it, even though it has been there for a good number of years 'behind the scenes'.

 

I still believe, with time, the synoptic patterns will favour a more blocked pattern, but everything this winter and quoting the above post "frustrating" does come to mind. Such an incredible start to the stratospheric winter season with all that wave 1 activity was, essentially, pointless (within reason of course) given how much the vortex then strengthened into early December. Clearly compared with last year we have and still continue to be in a much better scenario, but wherever there was positives at the beginning of the winter, equally "negatives" have appeared to balance things out in a very frustrating way. Take, for example, that low pressure over E Siberia which really scuppered the continued wave attacks by late November and also the complete lack of ability to get the MJO into more favourable phases, which, at other times of year it seems to just wonder into without any problems.

 

Still no change from me though in terms of the next 7 to 10 days, if not 14 days being zonal, overall. There's too many looking for something which won't appear on model threads and likes, everything is stacked against a quick return to significant northern blocking into early January and, once again, it is a waiting game. If we have to wait until late January or into February for a week to two weeks of deep cold and widespread snow, then I am certainly willing to wait. The UK's weather is never straightforward and never will be, it is only straightforward, to an extent, when an event or synoptic pattern has become established, just like the cold weather now for example, or like when the major Greenland blocking setup back in 09/10 etc etc.

 

Cheers, Matt.

[MattH]

Keep the faith...

 

 

Major warming over Greenland/NW of the UK still there, if not stronger from the 12Z ECMWF. Berlin charts tomorrow will be interesting viewing.

 

Matt.

[Catacol]

Keep the faith...

 

modelanalysis.PNGmodelanalysis1.pngmodelanalysis3.PNG

 

Major warming over Greenland/NW of the UK still there, if not stronger from the 12Z ECMWF. Berlin charts tomorrow will be interesting viewing.

 

Matt.

 

Yep - a very favourable setup from the 6th onwards provided it downwells efficiently. I'm very much a novice in understanding the mechanisms by which downwelling of a top down warming occur - but with a negative QBO and a vortex that is certainly weakened overall perhaps we can get a swift downwelling to occur. I've posted somewhere else that 6th Jan might be the point at which we see a chance for change: until then frost and then a return to mobility for a week or more.

[Catacol]

I think many people on internet forums, away from the professional side of things, have been bombared earlier this autumn and into early winter with the likes of the OPI which, despite various disclaimers from some, may well have left a lot of people thinking the majority of the winter would end up blocked and the UK to be bombared with E or NE'lies for weeks at a time, for example. The OPI, whilst for another discussion, is just one variable amongst many but it may well have been taken on board too much I feel in previous months now that a significant 'spot light' has been shone on to it, even though it has been there for a good number of years 'behind the scenes'.

 

Yes - but the OPI is an attempt to provide a forecast basis for NW Europe. That's fine - the experimental nature of it is well known - but it is still the case that siberian snow cover did not produce a substantial Siberian High when this was expected to occur, regardless of whether this led to cold air advected westwards. This is the bit that has surprised me: I thought the correlation between siberian snow and siberian high pressure was quite strong, and that the siberian high was a semi permanent feature in winter. I dont have the energy to trawl over past charts right now - so I'm posting without data to back up this feeling - but we do seem to have seen a lot of lowish pressure over the northern Asia continent this season.

[bluearmy]

The ECM 12z at 10 hpa is a big change from the 00z re temps and the vortex being squeezed by the Atlantic and pacific ridges.

The Berlin charts in the morning will indeed make interesting reading (especially the temp graph). Something certainly changed on thus run although the split does relent by day 10 as before. That renewed warming bound to have consequences but can we trust this run? (Huge differences between ECM and gfs strat on that run)

Edited December 28, 2014 by bluearmy

[Catacol]

Actually I've just done a quick trawal of the NCEP archives and my gut feeling would appear to be right - we have a really very low pressure profile over Asia/Siberia this year compared to previous years. The current top surface pressure of 1025Mb is way down on the usual for this time of year - at least as far back as 2004 when I stopped trawling...

 

Any thoughts on why?

[MPG]

The ECM 12z at 10 hpa is a big change from the 00z re temps and the vortex being squeezed by the Atlantic and pacific ridges.

The Berlin charts in the morning will indeed make interesting reading (especially the temp graph). Something certainly changed on thus run although the split does relent by day 10 as before. That renewed warming bound to have consequences but can we trust this run? (Huge differences between ECM and gfs strat on that run)

Do the stratosphere charts work in the same way as the model output? I mean, it seems when a favourable chart comes out people here seem to think it will come to fruition only to be disappointed when the next run down grades it? And also most of the time it's for a period in la la land.

Also, it's hard to understand if people are just discussing the stratosphere, or whether this is a hunt for uk cold 'stratosphere' thread.

Edited December 28, 2014 by MPG

[tcc]

Just touching on this, perhaps not directly strat related as such, but whilst there is a lot of winter left (and under the right synoptics at least the first half of March) the background 'signs and signals' have yet to come good. I think many people on internet forums, away from the professional side of things, have been bombared earlier this autumn and into early winter with the likes of the OPI which, despite various disclaimers from some, may well have left a lot of people thinking the majority of the winter would end up blocked and the UK to be bombared with E or NE'lies for weeks at a time, for example. The OPI, whilst for another discussion, is just one variable amongst many but it may well have been taken on board too much I feel in previous months now that a significant 'spot light' has been shone on to it, even though it has been there for a good number of years 'behind the scenes'.

 

I still believe, with time, the synoptic patterns will favour a more blocked pattern, but everything this winter and quoting the above post "frustrating" does come to mind. Such an incredible start to the stratospheric winter season with all that wave 1 activity was, essentially, pointless (within reason of course) given how much the vortex then strengthened into early December. Clearly compared with last year we have and still continue to be in a much better scenario, but wherever there was positives at the beginning of the winter, equally "negatives" have appeared to balance things out in a very frustrating way. Take, for example, that low pressure over E Siberia which really scuppered the continued wave attacks by late November and also the complete lack of ability to get the MJO into more favourable phases, which, at other times of year it seems to just wonder into without any problems.

 

Still no change from me though in terms of the next 7 to 10 days, if not 14 days being zonal, overall. There's too many looking for something which won't appear on model threads and likes, everything is stacked against a quick return to significant northern blocking into early January and, once again, it is a waiting game. If we have to wait until late January or into February for a week to two weeks of deep cold and widespread snow, then I am certainly willing to wait. The UK's weather is never straightforward and never will be, it is only straightforward, to an extent, when an event or synoptic pattern has become established, just like the cold weather now for example, or like when the major Greenland blocking setup back in 09/10 etc etc.

 

Cheers, Matt.

 

Easy for you to say Matt...you've seen some snow!   

[snowking]

Further support to a certain extent elsewhere for tonight's ECMWF 10mb explosion, most notably from JMA:

 

 

And to a slightly lesser extent, the NAVGEM:

 

 

It should be noted that whilst the GFS det. remains rather muted with this, the parallel run does still have some hints at an Atlantic sector warming:

 

 

So the signal for some sort of Atlantic warming is very much there, it's just the intensity which is open to question - let's hope for more of the ECMWF trend.

 

Would be interesting if Andrej is around to see what the extended JMA looks like

 

SK

[MPG]

Further support to a certain extent elsewhere for tonight's ECMWF 10mb explosion, most notably from JMA:

 

And to a slightly lesser extent, the NAVGEM:

 

 

It should be noted that whilst the GFS det. remains rather muted with this, the parallel run does still have some hints at an Atlantic sector warming:

 

 

So the signal for some sort of Atlantic warming is very much there, it's just the intensity which is open to question - let's hope for more of the ECMWF trend.

 

Would be interesting if Andrej is around to see what the extended JMA looks like

 

SK

Is that warming in the right location to increase UK cold chances? Also those charts are mega FI?

[LomondSnowstorm]

Is that warming in the right location to increase UK cold chances? Also those charts are mega FI?

In short, yes, you want as much warming towards Greenland as possible to give you the best possible chance of blocking setting up in a more favourable location for us. And actually it's far from FI in strat terms on the JMA and ECM at least, although given there's still a fair bit of divergence with the GFS at that range it's far from guaranteed. However, given almost all of the warming so far this winter has taken place over the other side of the pole this is certainly a positive trend.

[snowking]

Is that warming in the right location to increase UK cold chances? Also those charts are mega FI?

It's a question that is far too vast to answer in great detail.

 

UK cold chances - almost impossible to say at this juncture. I think people need to be able to make a distinction between the kind of talk that goes on in the model thread (far more specific and focussed) and the discussion that takes place here. Where as in the model thread we can look at charts showing the effects directly on the ground, what we are dealing with here is conditions spread across the entirety the Northern Hemisphere, and with a greater depth to forecast too (when we forecast at the surface we tend to look 2 dimensionally much of the time, where as in the stratosphere we are having to think about things in a more 3 dimensional manner). No two stratospheric warming events produce absolutely identical results. However, some of the better (and more instant responses to) stratospheric warming events have occurred when the warming takes place around the Atlantic/Greenland vicinity. Again, just to repeat, Nothing is guaranteed, and it is important for everyone to remember this when viewing this thread, to prevent it spiralling in to the chaos we see over in the model thread at times. But the reason for the desire for a Greenland warming this year is the stratospheric activity up until now has been largely Wave 1 based from the Pacific sector, and this has had the net effect of pushing much of the vortex energy (note: not a solid vortex, but still there nonetheless) over towards the Atlantic and Greenland - so a warming here could help to significantly reduce the influence of the polar vortex in this particular area.

 

In terms of are these charts FI, well whilst conditions are a little easier to predict in the stratosphere (due to the lack of surface effects, such as mountain ranges and oceans etc.) than in the troposphere, no model is infallible. The definition of FI for the stratosphere is a liquid one, and tends to depend upon intra-model (and indeed intra-run) differences. At the moment, with a strong disagreement with the GFS and ECMWF suites, I would recommend viewing current output as FI-type output. If by this time tomorrow the ECMWF (with greater stratospheric modelling overall vs GFS) is showing something similar to today's 12z run then a few in here may start to get excited.

 

Of course then the next stage is to decipher what the effects in the troposphere will be...

 

SK

Edited December 28, 2014 by snowking

[bluearmy]

18z gfsp picks out some n Atlantic warming in support of the ECM though not as toasty as the ECM

[mezzacyclone]

18z gfsp picks out some n Atlantic warming in support of the ECM though not as toasty as the ECM

Unless i'm encountering "excessive crimbo tipple wobble syndrome"? Then can you please edit your post BA? (Sorry but "ecm" & "ecm" dont compute at this hour for me after a fair few leffe blonde beers )

& also in relation to "SK"'s valued input, then what increased possibilities regarding ridges and/or location specific events etc, (away from the 'G Spot' of Greenland & should this increased union of Atlantic strat warming occur?) determine? (More apols for one too many commas? but i'm sure us "old skool" get the gist?)

Edited December 29, 2014 by mezzacyclone

[Skin]

Don't know whether this is stratosphere related, but are there signs of the QBO trending westerly by the middle of next year?

Yeah qbo data on Berlin shows. Westerly qbo starting at upper stratosphere. Now. Would take several months to peak at 20mb level.

[MattH]

Absolutely loving the 00z ECMWF at 10hPa!...

 

 

The signalled warming continues and not only that is even stronger than previous runs by 240hrs to the point that the structure of the 10hPa level, to me, looks to be on the verge of a SSW event. Not just as impressive down at 30hPa, but still the warming is signaled and split could well follow on further runs...

 

 

[ihatejam]

The signal from today's EC00z op run was pretty impressive and there is some decent ensemble support for it. In my mind there isn't much doubt about this warming anymore but the main question for me (and I'm sure everyone else) is how this will impact the lower atmosphere. What are your thoughts on this? From my memory, in the past the models have not done a good job of picking up on the response from the troposphere to a stratospheric warming. As an example, 2 years ago the EC model showed a strong warming signal which was correct but it was very slow to show the cold weather pattern that would develop over Europe. Does anyone have a good feeling for how the troposphere will respond to the stratosphere warming?

 

Thanks to all the regular posters on this forum. Whilst I have only just created an account I have been reading this forum for many years now.