Stratosphere Temperature Watch 2014/2015

[MattH]

Goes without question really given the variety of charts we have all been looking at, but still worth posting these two images of wave 1 and wave 2 activity at 10hPa at 60°N...

 

Recently, for the time of year, wave 1 activity is clearly knocking on the door of the highest recorded really and compared with this time last year it's clearly increasing compared with decreasing and essentially in an opposite state. Equally and in contrast wave 2 activity is generally 'below average' for the time of year and as I mentioned this morning, it is there in the 'background' but not really doing anything at the moment. It's wave 1 that continues to keep the vortex under wraps, to an extent for now and no doubt that'll keep the main vortex displaced away from the pole for the time being. We all know what wave 2 can do, but for now we need to keep hoping for the wave 1 activity to continue, as no rapid increase in wave 2 is likely. I'm struggling with the mountain torque images/web page as well as the images seem persistently corrupted of late and it's difficult to read them in terms of getting an idea of whether a mountain torque event is possible for example - http://www.esrl.noaa.gov/psd/map/images/reanalysis/aam_total/gltaum.90day.png

 

Cheers, Matt.

 

NB: Images for this brilliant site for observing actual conditions rather than forecast data... http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

[karlos1983]

liking that site a lot. Cheers Matt.

[lorenzo]

Sadly, the PSD maintenance of the page on GLAAM is under review 'due to retirement.'  Really ? When someone retires, the science retires? Very strange.

 

Nick Schiraldi site is a good one for GWO, also includes phase composites, indicates falling momentum. . http://www.esrl.noaa.gov/psd/map/clim/test_maproom.html

 

http://www.atmos.albany.edu/student/nschiral/gwo.html

 

The MERRA dataset is excellent, especially for comparing the projected Wave heights on each Berlin run against what actually verifies, the data as always bang up to date.

Edited November 6, 2014 by lorenzo

[Interitus]

 

 

The MERRA dataset is excellent, especially for comparing the projected Wave heights on each Berlin run against what actually verifies, the data as always bang up to date.

 

Just another quick mention for the ozonewatch site which is also part of the NASA MERRA set-up - as well as ozone (obviously) and some duplicated data there are some other metrics such as vorticity, vortex area and 45-75°N mean zonal wind which for some reason aren't included in the main MERRA link -

http://ozonewatch.gsfc.nasa.gov/meteorology/NH.html

[lorenzo]

The Canadian Warming thing still remains for me one of these long overdue mysteries. Am still not comfortable with my understanding of how they are classed among other displacement, split events, or even 'when' they get labelled a Canadian warming versus a displacement. Still from the archive found this analog of November CW years based on the Berlin data table, which looks like we are heading to Canada this November.

 

 

Good further tweet action Matt on the GWO and caveats for use of the site linked earlier beyond day 7 re: ensemble smoothing.

 

Edited November 6, 2014 by lorenzo

[Gael_Force]

I see the GFS is forecasting a split vortex at the end of the run - nothing dull this year - whatever the correct terminology, I'll just say it looks like the 'kitchen sink' is included this year. It's all happening up there and very early in the season too.

 

[Duane S.]

Wave 1 forecast looking healthy this morning...

Wave 2 quiet but maintaining a sustained 'bottom up' profile. Could have more impact than the intensity of the wave itself would imply?

Zonal wind speeds on the whole are about to peak and then start to wane across most levels. 30mb level is where I tend to keep an eye on as this seems to be influential, this year so far, very quiet. E-QBO keeping things nicely in check.

[karyo]

I see the GFS is forecasting a split vortex at the end of the run - nothing dull this year - whatever the correct terminology, I'll just say it looks like the 'kitchen sink' is included this year. It's all happening up there and very early in the season too.

 

The 0z GFS has taken a step back with a more organised vortex.

[feb1991blizzard]

Parallel looks good although cannot see vortex although Recretos will probably post it in his graphics later.

 

 

 

 

 

 

Warming continues to come into range of ECM though, we will have to wait and see whether it disrupts the vortex or not.

 

 

 

 

Saw that wave one chart and was going to post it at 5.45am but my connection was rubbish and fell asleep again!

[MattH]

The 0z GFS has taken a step back with a more organised vortex.

 

Indeed. Must admit despite the strat being a more 'stable' environment than the trop, I still put more faith in the ECMWF charts and output than these GFS charts which are out to 14 days or so. I think I mentioned the other day anything beyond 240hrs, to me, is speculative at best and can quickly change from one run to the next.

 

Yesterday's 12Z ECM continues it's development and whilst the 'better charts' still remain towards the end of the forecast period, the overal trend is for a more significant warming and a more significant amount of wave 1 activity as per the following images;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf10f240.gif

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

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ha1_f240.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_vt1_f240.gif

 

The USA are already seeing the influence, or will do, of an increasingly meridional pattern in the coming days but it's 'patience is a virtue' over here. That being said with charts like the below and how things are developing within the stratosphere, IMO, we are a 100 times better off than this time last year so far...

 

http://www.wetterzentrale.de/pics/Rtavn2401.gif

http://www.wetterzentrale.de/pics/Rgem2401.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

 

Regards, Matt.

[MattH]

Will it, won't it...

 

It's a bit nearer to present day but still a long way away time frame wise, but what it is interesting is clearly there is consistency over this significant warming from the ECM EPS within the next 10 to 14 days. It seems such a strong signal from an ensemble than compared with a Deterministic model and again there is consistency too. Clearly still time for a change, but IF this did come about it would surely have some significant implications towards the end of the month and beyond and at a minimum continue to put the strat vortex under some significant 'pressure' early in the season.

 

Cheers, Matt.

[bluearmy]

compared to the chart from 36 hours ago, i`'d say the anomoly was, if anything, strengthening slightly matt.

[chionomaniac]

Happy with that, thanks Matt. Is there any indication that the lower vortex is put under any wave 2 stress at any time? That looks like classic wave 1 Canadian type warming - one that is severe enough to pressure the vortex, but not displace totally (so no mean wind reversal at 10hPa)

 

Oh and to edit the scale needs increasing as the warming could be a lot better than the present scale shows!

Edited November 7, 2014 by chionomaniac

[MattH]

Ed...

Let me know what specific charts would highlight that and I'll see what I can find.

Matt.

[chionomaniac]

Ed...

Let me know what specific charts would highlight that and I'll see what I can find.

Matt.

Cheers. Ensemble options for lower strat from 100 to possibly 30hpa to see if trop wave 2 activity is penetrating into lower strat and creating split especially Greenland Plateau based. 

 

(Edit  from T+240 onwards)

Edited November 7, 2014 by chionomaniac

[Frozen Britain]

Yes we should - my discussion always contains a lot of self caution, but the evidence is strong that we will see that disrupted trop vortex -  I would term the November outlook as a modified high SAI November outlook. Note that the forecast anomaly charts have 3 of the requirements: - Atlantic trough towards the UK, Aleutian trough and Scandi/Russian positive anomaly.

So what northern hemispheric pattern would we have ideally like to have seen this month as opposed to the 3 requirements you point out that we have now?

What setup would give us an Atlantic/Pacific rather than Canada/Russia northern hemisphere pattern?

What do we need to see in the modelling to increase wave 2?

Edited November 7, 2014 by Frozen Britain

[chionomaniac]

So what northern hemispheric pattern would we have ideally like to have seen this month as opposed to the 3 requirements you point out that we have now?

What setup would give us an Atlantic/Pacific rather than Canada/Russia northern hemisphere pattern?

What do we need to see in the modelling to increase wave 2?

No I want this set up - because of the implications in the heart of winter.

 

The other set up, the amber nectar, is the wave 2 trop led wave break into the strat from the Greenland plateau, but I would still rather wait for that until at least December, when the benefits will be greater.

[Frozen Britain]

No I want this set up - because of the implications in the heart of winter.

 

The other set up, the amber nectar, is the wave 2 trop led wave break into the strat from the Greenland plateau, but I would still rather wait for that until at least December, when the benefits will be greater.

So the troughs and ridges are in the right place?

 

Why do you say about Atlantic/Pacific for Greenland blocking as opposed to the Canada/Russia set up that is in the modelling now?

[MattH]

Ed,

Find attached 294hr at 50hpa. There's possible signs of a split there near to Greenland. I think all eyes need to be on the ECMWF wave 2 charts next few days from Berlin. I'm with you though, the holy grail can wait until into December but beggers can't be choosers!

Cheers. Matt.

Edited November 7, 2014 by MattHugo

[mcweather]

No I want this set up - because of the implications in the heart of winter.

 

The other set up, the amber nectar, is the wave 2 trop led wave break into the strat from the Greenland plateau, but I would still rather wait for that until at least December, when the benefits will be greater.

 

I,m with you Chiono there is no point getting the' holy grail' now We just need to keep sseing the vortex under attack and weakening so that we can then decimate it with wave 2 trop led wave breaking during december that way we could get a really cold winter overall instead of just an early spell and not much else like 2010/11.

[feb1991blizzard]

No I want this set up - because of the implications in the heart of winter.

 

The other set up, the amber nectar, is the wave 2 trop led wave break into the strat from the Greenland plateau, but I would still rather wait for that until at least December, when the benefits will be greater.

 

Is that because of what you said in the MOD thread earlier about wasting time wrt the vortex re-strengthening and could you forsee a 96-97 type winter if what you mentioned happened too early?

[chionomaniac]

Ed,

Find attached 294hr at 50hpa. There's possible signs of a split there near to Greenland. I think all eyes need to be on the ECMWF wave 2 charts next few days from Berlin. I'm with you though, the holy grail can wait until into December but beggers can't be choosers!

Cheers. Matt.

Thanks Matt.

 

 

The problem that I have at the moment is that we are seeing trop height rises spreading from Scandi towards Greenland, the wave 2 spreading west. What would be better ( and I know beggers can't be choosers) is an amplified trop flow that creates a wave 2 scenario based with the classic Greenland tip split flow with associated WAA across west Greenland. This wave activity deflects perfectly (across that wonderful isotrope of delight!) right into the strat as compared to the westward movement of Scandi raised anomalies. Because of the plateau affect, the Greenland based upwelling split is severe enough to be long lasting and no transient feature and can repeat. 

 

Hints from that mean 50hPa chart suggest that we can't rule that out, so promising!

[lorenzo]

Just lost myself in the loops on this site for the last 20 minutes, the 100hPa waves first of all then the temp ones, then the PV ones.. ! 

 

Amazing watch.

 

50hPa from 26 October image attached.

 

 

Loop here 

 

http://www.pa.op.dlr.de/arctic/ecmwf.php?im=3

 

After that click on the 20hPa one and check that wave fire round. Ouch !

[ITSY]

In layman terms can someone explain the potential trophespheric impacts of the much mooted "wave 2" activity soon to take place? I've barely scratched the surface of what this means - and where we want it to occur!

[chionomaniac]

In layman terms can someone explain the potential trophespheric impacts of the much mooted "wave 2" activity soon to take place? I've barely scratched the surface of what this means - and where we want it to occur!

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.

 

 

 

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.