Stratosphere Temperature Watch 2012/2013

[MattH]

General update from me but the GFS Det once again looks interesting long term and manages to split the vortex but also continues to introduce an area of warming over Asia;

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121116/00/348/npst30.png

It does consolidate at the end of the run, but clearly that area of 'warmth' remains quite noteworthy;

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121116/00/384/npst30.png

The 12Z (15Nov12) ECMWF changes little. The wave 2 activity peaks near day 5/6 now before then waning somewhat, otherwise the charts from the ECMWF, that I can see, remain very similar to previous days with nothing really to get excited about;

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ha2_f144.gif

Signs of the strat becoming quite elongated on the ECM as well out to 240hrs, but clearly could be a lot better given the temperatures still forecast 'up there';

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

Finally the overnight update of the ECMWF 32 day maintains a strong meridional pattern to become established by late November and into early December across the North Atlantic. It still, yes still, implies that blocking will become noteworthy to the north or north-west of the UK with a +ve pressure anom expected to develop. With pressure lowering across southern areas of Europe, this maintains the trend for temperatures across the UK to drop below average into early December either from a N or NE'ly source.

Clearly the consistency of the model can't be faltered, but even at this stage I do find some of the synoptics it is showing for early December hard to believe. Again though, forecast model consistency is what interests me as a forecast model, particularly at length, so as part of my own blog today, that's the side I'll be leaning towards for early December. Something colder, but something generally drier. I can't wait to see if the ECMWF actually becomes reality now to be honest after it showing this same signal for well over a week or more.

It's a case of almost sitting back and waiting and seeing what happens now with the strat and more upper level conditions during the second half of November.

Regards to all, have a good weekend.

M.

[Ice BIast]

Is the signal for blocking on the 32 dayer strong Matt?

[chionomaniac]

Is the signal for blocking on the 32 dayer strong Matt?

When Matt says that 'a strong meridional pattern to become established' I would read that as the signal for blocking is strong and is continued to the end of the ECM 32 day run.

I suspect that we will have another strong burst of wave 2 activity in the 10-15 day timeframe that will help trigger that.

[chionomaniac]

The JMA have a strat monitoring section - here's their winter forecast fresh 'off the presses' today.

http://ds.data.jma.g...map1/pztmap.php

I have explored that link a little more, GF. So thanks for it.

I have found through it another forecast that is supporting blocking for early February, and another link that we can use.

Here are the H500 anomaly forecasts for weeks 3/4 (first 2 weeks Dec) released 15/11/12.

This shows a positive anomaly over the North Atlantic extending towards Greenland - so more support fo a possible northerly airflow during the first few weeks of December. This fits in well with the ECM 32 day update.

The JMA is also suggesting an easterly Feb

http://ds.data.jma.g...odel/index.html

Edited November 16, 2012 by chionomaniac

[Catacol]

January looks to be a NW month on that prediction with low pressure to the south implying a lot of southerly tracking in the atlantic pattern. While Easterlies and Northerlies are sought after by all coldies (Dec and Feb look good) I must admit I have wondered for a while what a very southerly tracking jet might do to us in January. Since I have been following the weather closely on this forum and on TWO I have yet to experience or see what might happen if systems spin their way down over France/Spain dragging colder air onto the northern flank in a high precipitation type of scenario such as is painted in the Jan chart. I could see some serious snow fall for certain favoured areas in that scenario, provided the cold to our East is embedded strongly enough. What encourages me a lot on that chart is the fact that the low pressure anomaly as forecast is strong only over the southern tip of greenland and quickly fades to close to average over and to the east of the UK. That does not imply a dominant zonal express.

Interesting indeed.

EDIT: mind you, backtracking to their previous run their anomaly forecast for December was totally different a month ago to what it is now. Another forecast model then that, at long range, doesnt have a clue. I have a lot more faith in GP's handling of the combined state of affairs - at least in Winter time anyway. :-)

Edited November 16, 2012 by Catacol_Highlander

[chionomaniac]

Signs of warming forecast at 1 hPa (top of strat) on the GFS as well as ECM.

Sometimes these warmings make there way down to lower levels (mid strat), so worth watching. I am expecting this to work it's way down following the increased wave activity, but I am unsure how strong this will be.

[summer blizzard]

Signs of warming forecast at 1 hPa (top of strat) on the GFS as well as ECM.

Sometimes these warmings make there way down to lower levels (mid strat), so worth watching. I am expecting this to work it's way down following the increased wave activity, but I am unsure how strong this will be.

I recall reading somewhere that the placement of a warming is important and that Atlantic warmings are generally less good.

[chionomaniac]

I recall reading somewhere that the placement of a warming is important and that Atlantic warmings are generally less good.

I think that very much depends on whether the warming breaks the surf zone and becomes intergrated into the vortex. The warming areas tend to be in the same positions - downwind of the continental mountains.

[chionomaniac]

Another good FI stratospheric run from the 12Z GFS.

I am liking the end which shows the best warming yet, with a distorted vortex at 30 hPa.

[phil nw.]

Another good FI stratospheric run from the 12Z GFS.

I am liking the end which shows the best warming yet, with a distorted vortex at 30 hPa.

Yes Ed the 2 main centres pulled east and west leaving that gap for some Greenland height building.

It helps to show why we continue to see the trophosphere models favour some form of ridging towards that area from as early as next weekend.

We just need the knockout blow from a stronger wave break to split the pv apart.

[VillagePlank]

Does anyone have any links to a historic daily strat temperature series. I've had a quick look and I can't find anything ....

[chionomaniac]

Does anyone have any links to a historic daily strat temperature series. I've had a quick look and I can't find anything ....

I have never come across a daily dataset, BW.

[Relativistic]

Does anyone have any links to a historic daily strat temperature series. I've had a quick look and I can't find anything ....

This page may be of use:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/

Look at past years data and you can see temperature graphics of each year back to 1979 for all levels of the stratosphere and the troposphere.

[Duane S.]

Looking mid strat wise:

The cooling continues, this must be close to record temperature for this time year. Not good, but not good if only taken at face value.

Still no signs that +30 m/s zonal winds really wanting to propogate down to that level. e-QBO possibly the culprit from keeping them at bay and keeping our options firmly open. One thing that I have noticed is that the slow transition from equatiorial negative wind anamoly to positive seems to be being delayed? Obviously it will switch but it has tapered off at the top of the strat for now, that appears to my eyes to be quite unusual and I would imagine can only work in our favour.

In just a couple of weeks the top end of the strat will have passed its winter low point and we would expect temps to be on the up again. The impact of that on other factors that influence the troposphere more directly may be tenuous, I'll leave that for the experts.

[AWD]

With charts like the above, we are going to need a relatively big warming just to get the 30hpa temps back up to average, let alone anything warmer.

[Cloud 10]

Things can change very quickly in the stratosphere as can be seen by last winter's temperature

graph.

Temperatures at 30hpa for this year are pretty much identical to this time last year,

last year..

[chionomaniac]

Just a quick one.

30 hPA Split and warming GFS 6Z FI - nice!

[EML Network]

Things can change very quickly in the stratosphere as can be seen by last winter's temperature

graph.

Temperatures at 30hpa for this year are pretty much identical to this time last year,

last year..

Is there any evidence to suggest that the lower the temperature goes, the more extreme any following SSW event is ?? ..it's just that chart screams ''coiled spring'' and I am wondering if there is any correlation between SSW events being more pronounced or extreme when the preceeding temperature is so very low ?

Edited November 17, 2012 by EML Network

[summer blizzard]

Just a quick one.

30 hPA Split and warming GFS 6Z FI - nice!

Sadly, nothing shown before Dec 2nd.

[bluearmy]

As long as the wave 2 stuff keeps going we could keep the strongest zonal winds away from the trop. Evidence this morning that as the current wave 2 stuff begins to wane, the winds begin to downwell slowly again.

[summer blizzard]

A split at day 11 from the 12z before a reformation at day 13.

[Cloud 10]

Is there any evidence to suggest that the lower the temperature goes, the more extreme any following SSW event is ?? ..it's just that chart screams ''coiled spring'' and I am wondering if there is any correlation between SSW events being more pronounced or extreme when the preceeding temperature is so very low ?

Only looked through 10 years but doesn't seem to be the case.

Feel free to have a butcher's though.

Climate Prediction Center - Global Temperature Time Series

[bluearmy]

Even clearer on the ecm update that the wave 2 activity supresses the zonal wind strength over the next week. Thereafter, the activity drops off and the wind begins to downell again. Some wave 1 showing up to follow the wave 2. the vortex still appears deformed on the forecasts but not as much as it did a few days ago. temps are no longer dropping in the mid strat but thats more likley because they are about as low as they can go!

[MattH]

Even clearer on the ecm update that the wave 2 activity supresses the zonal wind strength over the next week. Thereafter, the activity drops off and the wind begins to downell again. Some wave 1 showing up to follow the wave 2. the vortex still appears deformed on the forecasts but not as much as it did a few days ago. temps are no longer dropping in the mid strat but thats more likley because they are about as low as they can go!

I think this sums it up well to date. The wave 2 activity looks set to wane, but the 12Z ECMWF from yesterday clearly shows wave 1 potentially on the up now. The 00Z GFS continues to show the vortex becoming very elongated by early December, if not still splitting and also with the pronounced region of warmth developing over Asia at the 30hPa as well. As ever this is clearly a long way off, but the more consistency then in theory the greater the risk of things developing like that.

Must admit given that the deterministic models are now coming into alignment (of sorts) with the ECMWF 32 day, I still find it hard to believe we are likely to progress towards a more meridional/blocked pattern by late November given the state of the strat. I guess it shows that despite a very active and cold strat, if other variables are counterbalancing it, then blocking and potentially colder weather is still possible.

M.

Edited November 18, 2012 by MattHugo

[Duane S.]

Good to see Wave 1 forecast to take over where wave 2 leaves off.

Be interesting to monitor its strength of the next week or so. Presumably this will put a different form of pressure on the vortex than wave 2. With one trying to split and one trying to displace it, hopefully like a disorientated boxer it will eventually throw in the towel but there is some mighty cooling going on in there.

Does make you wonder. How BAD would it likely be if we didn't have the opposing forces to the cooling strat? Conversely, how GOOD could it have been without the cooling strat!?