Stratosphere Temperature Watch 2014/2015

[karyo]

you speak of détermiste GFS? because the GFS // this is another story and very different. Do not look at the GFS détermiste soon to be replaced

I look at the GFS not the GFS p. It was showing another warming for early December which has now pretty much gone.

Edited November 24, 2014 by karyo

[Skin]

Wave 1 activity is forecast to back off, but its still strong even at that. 2200 m/s to 1600 m/s at the upper strats. but definitely Wave2 is going to take over.  Definitely reminds you of 2009 this time of year. 

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha1&lng=eng#fig1

[feb1991blizzard]

Wave 1 activity is forecast to back off, but its still strong even at that. 2200 m/s to 1600 m/s at the upper strats. but definitely Wave2 is going to take over.  Definitely reminds you of 2009 this time of year. 

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha1&lng=eng#fig1

 

you mean metres not metres / s

[KyleHenry]

GFS is a Match on wave 2 with temps in comparison with ECWMF at the 10 hPa level . But is not showing similar to ECWMF in regards to next wave inbound.

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

But look at ECWMF at the 1 hPa level at 240z dated 23rd Nov at the Greenland region

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

and there you see the possibilities of wave 3 or new wave 1 upwelling into Stratosphere at a position where the UK needs it to be.

10 days out but to see signals of the next warming is great.

386 z on ECMWF 10hPa forecasts no split of PV, but if this next phase at 1hPa level materialises and down wells there'll be smiles a plenty.

Greenland region 10 day count down plus the usual 3-4 weeks delay and Bobs your Uncle

[ukpaul]

I look at the GFS not the GFS p. It was showing another warming for early December which has now pretty much gone.

 

The GFSp is run at a higher resolution and is taking over from the GFS soon, it should, therefore, be more trustworthy and reliable. As such I've stopped looking at the GFS run, apart from for fun (or not)

[KyleHenry]

MJO phases are proving a lot more influential this year as apposed to last.

Bit of straw clutching here and going beyond current forecast but MJO could be going into phase 8 around 10th December.

The GEFS is picking up on a few colder runs for same time.

[karyo]

The GFSp is run at a higher resolution and is taking over from the GFS soon, it should, therefore, be more trustworthy and reliable. As such I've stopped looking at the GFS run, apart from for fun (or not)

But is the GFS p showing something more promising for December?

 

Either way it will have to show on both versions if it is going to happen.

[ukpaul]

But is the GFS p showing something more promising for December?

 

Either way it will have to show on both versions if it is going to happen.

 

If a model has better resolution it is the one to follow and the new GFS does, especially out to 240h. Seriously, the old GFS is for the bin, why else are they upgrading it?

[feb1991blizzard]

If a model has better resolution it is the one to follow and the new GFS does, especially out to 240h. Seriously, the old GFS is for the bin, why else are they upgrading it?

 

True but they have delayed its upgrade, its looking like the stats show it is indeed an upgrade but they cannot have been sure it would verify better else they wouldn't have run them side by side, they would have just binned the old one, always worth using all the data available.

[Recretos]

Well, yes. Tho the resolution is an important part of the model, its partially inferior to its physics. You see, you can have a global model with 5km resolution, but if its physics are a bit off, it wont do any better than some global model with 20km or 30km resolution with better physics.

Its not how many points you have, but how quality calculations can you make on each point. Tho of course in this day and age the physics are comparable, but in our situation with the GFS, it got a resolution increase together with some physics change (grid from Eulerian to semi-Lagrangian), so the verification is not that straight forward, and it takes more time.

 

As far as the strat goes, the para does seem to be generally less biased than GFS, at least at 240h. And later on, it is generally a bit better, but its hard to say without serious dynamics in the forecasted range. 

In summer time, the normal GFS was better for the strat, but in the winter time, at least last season and this year so far, it appears that para was a bit better. Tho I think the new (latest) cycle is PRX, not PRHW14, but its pretty much a similar thing.

 

 

 

We will see in time.

 

Regards

[neige57]

Increased WAVE2 this morning and WAVE1 still holds up, it has not changed compared to yesterday concerning

 

 

 

 

What is interesting is that we are not far from a reversal of zonal winds and it will be monitored. In any case, the strong QBO- is doing his work

 

 

Edited November 25, 2014 by neige57

[Skin]

[joggs]

Sorry,whats the above showing Skin?

Thanks in advance.

Edited November 25, 2014 by joggs

[MattH]

The wait for that killer blow continues and will do for a number of weeks yet, it would seem, but this is what was expected overall and is no real surprise. There are some concerning charts longer term from the GFS and the GFS(P) in terms of the vortex getting some organisation as we move into early December. Clearly nothing on the scale of last year, but given a reasonable split within the short term charts like the following aren't really all that great;

 

 

 

 

 

Clearly a long way to go but for the time being attention is turned towards the troposphere to see what happens 'down there' with regards to any high pressure into December. Clearly it isn't all about the stratosphere and developments within the troposphere will no doubt have some influence on the strat at some point this winter. But it's a case of 'steady away' within the stratosphere, wave 1 activity has certainly done some damage early in the season and wave 2 activity is set to increase somewhat, but still remain below 'significant levels'.

 

Be interesting to see how things pan out during the first half of December and whether the above organisation does actually come off. I still but can't help think that at some point a more zonal spell will dominate in December before we do end up with the 'proper' winter synoptics late in December and into January, but once again it's not all about the stratosphere and some cold synoptics could still materialise without the aid of a SSW just yet. After last winter an anticyclonic spell, as being signalled for next week for example is still a heck of a lot of better. This time last year we were struggling to get temporary ridging let alone the potential for pressure over 1020mb for a number of days, so the wait goes on...

 

Cheers, Matt.

Edited November 25, 2014 by MattHugo

[Skin]

Sorry,whats the above showing Skin?

Thanks in advance.

 

 

warm Temp anomalies already appearing on several levels of the Strat. Will it be strong enough? thats the kicker.

[bluearmy]

Some mixed messages this morning

EPV heads south at the end of the run. anomoly or trend.?

zonal flow increases at the top of the strat as wave 1 relaxes somewhat. That ties in with gfs fi.

Some impressive zonal reversal above 70N before then, both high up and low down.

I suspect we will see an increase in the upper vortex strength along with an uptick in zonal flow up there. That could well tie in with the AO going positive down here. However, the AO is then predicted to go neg again and the renewed trop forcing from WAA pumped into the lower strat in various points of the NH should induce an episode of renewed strong wave activity which this time, could deal the vortex a bigger blow and potentially bring about an SSW. timescale on that is beyond mid dec.

[snowking]

One positive from me today. Take a look at the following sequences:

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ecpv.php?alert=1&level=1000&forecast=all&lng=eng

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ecpv.php?alert=1&level=850&forecast=all&lng=eng

Note the tendency for much of the vortex 'energy' to transfer towards the Siberian sector. We should of course bear in mind that this is only taking place at two of the higher isentropic levels and right towards the end of the run, but this is certainly a trend we would like to see downwelling as we head through December.

SK

Edited November 26, 2014 by snowking

[feb1991blizzard]

Another round of warming possibly, starting at the top, more pronounced on ECM than GFS.

 

Edited November 26, 2014 by feb1991blizzard

[Recretos]

One positive from me today. Take a look at the following sequences:

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ecpv.php?alert=1&level=1000&forecast=all&lng=eng

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ecpv.php?alert=1&level=850&forecast=all&lng=eng

Note the tendency for much of the vortex 'energy' to transfer towards the Siberian sector. We should of course bear in mind that this is only taking place at two of the higher isentropic levels and right towards the end of the run, but this is certainly a trend we would like to see downwelling as we head through December.

SK

 

Yes, I was kinda expecting something like this, as I was trying to say in my "mysterious" posts, as we move into December, for the vortex to try and re organize and start moving, but not achieving its full potential, and the wave 1 kinda present at all times, tho not as strong as in the current days.  This is just another step on the road. If this transfer will slowly complete, (perhaps not so fast as ECM has it, but still), I expect new waves to slowly re-emerge, as I was saying then. I would also expect the Atlantic wave to slowly start emerging from its long slumber.

 

Regards

[Skin]

By definition, are we seeing a Canadian warming? Only seen a few papers talking about it. Guess it depends on who's definition you use. Lol!

http://birner.atmos.colostate.edu/papers/Butleretal_BAMS2014_submit.pdf

 

Canadian warmings (early winter warmings marked by a poleward shift of the Aleutian high) 

 

But different studies implement these classifications in different ways. For example, some studies (e.g., Charlton and Polvani 2007) classify Canadian warmings as major warmings if a circulation reversal occurs, while others (Labitzke 1977) argue  against this based on differences in synoptic development.

[karyo]

Both the GFS and the GFS p continue to show an intensification of the polar vortex as we progress into December. The current warming fades away. The 90 degrees N graph shows the temperatures back to average after a couple of days slightly above and heading down.

 

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra/t90n_50_2014_merra.pdf

 

It will be a shame if the warmings we have experienced through November just get wiped out in December.

 

Karyo

[MattH]

Both the GFS and the GFS p continue to show an intensification of the polar vortex as we progress into December. The current warming fades away. The 90 degrees N graph shows the temperatures back to average after a couple of days slightly above and heading down.

 

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra/t90n_50_2014_merra.pdf

 

It will be a shame if the warmings we have experienced through November just get wiped out in December.

 

Karyo

 

Compared with the autumn up to present the outlook does look like being relatively quiet now with regards to wave 1 and 2 activity and this, as you highlight, does allow some consolidation of the vortex into a more uniform feature after being pretty much two seperate vortex's at present. However, it is just a matter of time before wave 1 and hopefully and more importantly wave 2 activity returns the deeper we progress into December. I don't believe there is much chance of things "getting wiped out in December" as you mention simply because the vortex still remains in a weakened state and is nothing like last year. The -QBO will help, at least, to continue to keep the vortex under it's "thumb" until we get something significant (wave 1 or 2 activity) further down the line.

 

The signal for potential ridging towards Greenland into early December is, something which I think will really help the cause. Clearly like just any other synoptic development it may or may not happen, but getting that meridional flow and potential warmth pumping northwards will help the wave activity further down the line. No-one ever said that a SSW would happen in November, the concensus has always been mid to late December onwards as a prime period and clearly a heck of a lot can and will happen no doubt between the 27th of November and the 27th of December in the next month.

 

As I mentioned the other day, for the time being at least, it's a case of 'eyes down' to see what's going on in the troposphere for now, hence the lack of posts in here within the last 24 to 48hrs...

 

Regards, Matt.

[karyo]

Hi Matt, thank you for the response. A SSW in November was not what was expected but I was hoping for small warnings to continue in December like the Gfs was showing up to a week ago.

Karyo

[Recretos]

Matt has beaten me to it again, but I will finish this quick analysis nonetheless, since I was already mostly done.

 

Despite the activity waning, which was to be expected, the damage has been done, and the full vortex power like last year, was denied or rejected or prevented, for the time being. As I have said a few times so far, the troposphere has the more dominant role this year, as the general stratospheric state is for now disorganized and not compact and "columnised". Due to all the wave activity, QBO phasing and strong tropospheric forcing, the vortex has a much lover angular momentum than last year and a weaker core. It has (had) more meridional momentum component and lower zonal momentum component. Due to weaker core in general and the pressure gradient force, the polar jet is weaker along with the pretty much entire vortex (or vice-versa, as you wish). With the vortex in such a state, the strong tropospheric forcing comes to more importance and basically dominates the lower strat in a ratio around 70-30 for the troposphere. Higher up, there is this "surf zone" in the mid strat, while the upper strat has had its own dynamics which never down-welled quite far. And that was what even the normal GFS was signalling in the mid range. Unlike last year with a very organised and complex vortex with great angular momentum and strong core, which downright dominated the entire atmospheric column, and we know what the outcome was. 

 

Ok, enough plain text for now. These are height and temperature anomalies for last year, for the 7/12, which is the date of current 240h forecasts. We wont go beyond that for known reasons. Very organised and focused anomalies, and this is only one level in the mid strat. 

 

 

 

Now if we look at the entire column comparison to last year. 

It is getting clear how the re-organisation of the vortex is more limited to mid strat in the first phase, as it takes a bit longer for the wave activity to back off in the higher levels. And it is more bound to the core region. So pretty much a normal mid strat reorganisation in this phase. The height and zonal wind comparisons speak the loudest how disorganized the vortex column is compared to last year. And the temperature of course. 

 

  

 

Nothing too wild in the strat for now, and neither to be expected in a reasonable range. I wont go beyond 240h, because that is where the model biases come more into play and that is a problem when doing day-to-day or year-to-year comparisons. 240h is a generally good range. 

 

So much for now. 

 

Regards. 

 

Edit: 
 

Adding the full vertical profile reanalysis from last year, from MERRA.

 

Edited November 27, 2014 by Recretos

[MattH]

Just wanted to post the following in here as a reference for further down the line....

 

 

Matt.