Stratosphere Temperature Watch 2011/2012

[chionomaniac]

No warming forecast in the stratosphere as of yet but an interesting split is forecast to develop over the coming days. This does not look like one that will see the disintergration of the vortex but I can only guess that this is in response to some kind of wave break without the warming?

The split is not in a favourable position for Greenland blocking but certainly areas to the NE could be affected bu height rises. Interestingly this is not a lower tropospheric split but is forecast throughout the whole height of the stratosphere.

[Eugene]

What do the stratospheric experts feel will occur later next week, do you feel we will have a big HP cell over central europe like GFS 06Z OP - http://www.wetterzentrale.de/pics/Rtavn2041.png

Or do you think we'll see the models trending to move the HP cell further north to sit to our NE like GEM 00Z does?

http://www.wetterzentrale.de/pics/Rgem2041.gif

[Weather-history]

Gone very quiet this thread.

A warming of the higher levels of the stratosphere is still being forecast

[summer blizzard]

The 10hpa is still below what it was this time last year.

While the vortex may well weaken a little i think that it will largely continue to produce the current pattern until warming is stron enough to down-well fully.

[phil nw.]

Gone very quiet this thread.

A warming of the higher levels of the stratosphere is still being forecast

Yes a good warming is forecast at the higher 1hPa level that`s for sure and is pretty much underway now.

here at T72hrs for instance

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf1f72.gif

and by T240hrs.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf1f240.gif

However as SB says this is not yet forecasted to get much lower, so at mid-levels and down still the status quo with no sign yet of a final warming.

[damianslaw]

Yes a good warming is forecast at the higher 1hPa level that`s for sure and is pretty much underway now.

here at T72hrs for instance

http://wekuw.met.fu-...1/ecmwf1f72.gif

and by T240hrs.

http://wekuw.met.fu-.../ecmwf1f240.gif

However as SB says this is not yet forecasted to get much lower, so at mid-levels and down still the status quo with no sign yet of a final warming.

We seem to have been stuck in a status quo situ for ages.. will the vortex ever break up or move? Its persistance is very notable - how normal is it to remain locked in the same position for such a long time. It is maintaining the azores high influence and the prime reason for why it has been dry for so long - could do with it clearing off for a while to allow some much welcome rain for southern and eastern parts.

Waiting for propogation of warming from the strat down to lower levels has been like waiting for paint to dry.

[Alex]

We seem to have been stuck in a status quo situ for ages.. will the vortex ever break up or move? Its persistance is very notable - how normal is it to remain locked in the same position for such a long time. It is maintaining the azores high influence and the prime reason for why it has been dry for so long - could do with it clearing off for a while to allow some much welcome rain for southern and eastern parts.

Waiting for propogation of warming from the strat down to lower levels has been like waiting for paint to dry.

Question I have is will it definitely happen, ie are any years clear of a warming at lower levels?

[karyo]

The cold stratosphere has been a treat for the Arctic ice, keeping the cold locked there. As a result, the ice extend is much greater this year compared to the last few years. I hope we don't see a significant warming so that spring melt will be slow.

Karyo

[Eugene]

So does anybody think any strat warming might be on the cards later this March into April?

Looking like a blocked pattern developing on GFS 12Z and some ensembles are pushing HP further north and east so a nice bit of strat warming might help down the line.

[chionomaniac]

So does anybody think any strat warming might be on the cards later this March into April?

Looking like a blocked pattern developing on GFS 12Z and some ensembles are pushing HP further north and east so a nice bit of strat warming might help down the line.

The stratosphere will be warming any way at this time of year, Eugene. There are no indications that any dramatic events are likely to occur now and even if they were, any tropospheric effects would be very limited.

[Eugene]

Ok thanks chionomaniac, so any blocking occuring is just natural seasonal changes.

[Don]

Ok thanks chionomaniac, so any blocking occuring is just natural seasonal changes.

I think that's it now for stratosphere temperature watching until October/November. Hopefully things will be more promising earlier for next Winter!

Edited March 14, 2012 by Don

[picog]

It's all gone a bit cold again recently.

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

[492]

GFS FI has been indicating a marked warming at 10hpa which looks as dramatic as the warming that occurred during January. This predicted warming looks more dramatic than what I would have expected for normal seasonal warming. If it verifies are we likely to end up with a Greeland high later in April with deepish cold air over the UK.

[Cloud 10]

GFS FI has been indicating a marked warming at 10hpa which looks as dramatic as the warming that occurred during January. This predicted warming looks more dramatic than what I would have expected for normal seasonal warming. If it verifies are we likely to end up with a Greeland high later in April with deepish cold air over the UK.

Quite a sharp warming showing up at 30hpa as well,albeit at day 10.

Perhaps more model output like the chart below to come over the next week or so.

[492]

The continued predicted warming at 10hpa on GFS results in the PV that has been resident to the east of Greenland for most of the winter being entirely replaced by a significant warm area albeit deep in FI. If it verifies It will facinating to see how much this affects the troposphere during the second half of April.

[Glacier Point]

Want to try something here. Based upon the projection of the tropical waves, mountain torques and warming of the stratosphere, to attempt to predict either a strong warming event of potentially early final warming.

As the MJO wave moves through the Indian Ocean, it can trigger strong posiitve mountain torques over the Himalayas. Currently very negative, these mountain torques reversing could potentially trigger remote wave breaking and disruption of the polar vortex.

So key timelines to watch for:

- MJO moving through phase 3/4 and developing high amplitude - - 1st March

- Strong positive mountain torques and rapid increase in tendency in relative angular momentum -- 1st - 10th March

- Rapid increase in high and middle stratosphere temperatures -- 12th through 22nd March

- Blocking signatures in the troposphere developing -- 22nd March through 11th April.

- MJO moving through phase 3/4 and developing high amplitude - - 1st March

.. moved through several days later on, 5th-6th March

- Strong positive mountain torques and rapid increase in tendency in relative angular momentum -- 1st - 10th March

.. first mountain torque on 10th March and second on 20th March, not overly impressive but a very impressive spike in tendency in angular momentum centred on 12th March (I suspect this is causal to current modelling indicating blocking structures in high latitudes).

- Rapid increase in high and middle stratosphere temperatures -- 12th through 22nd March

No rapid increase seen as yet, although 30 mb temperatures have gone above normal and 10 mb forecast to rise above normal today (was the lack of a strong Asian Mountain torque the issue here?)

- Blocking signatures in the troposphere developing -- 22nd March through 11th April.

Tropospherically, definate signs of this, more Gulf of Alaska and Pacific side - probably more related to tropospheric influence rather than stratospheric ?

Edited March 28, 2012 by Glacier Point

[phil nw.]

As expected warming out of the vortex is forecasted at all levels as we go into April.

10 day temp. and zonal wind reduction forecasts at high latitudes show up here.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_t_f240.gif

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_u_f240.gif

The pressure forecasts from CPC suggest as the vortex wanes and fragments the main core of low heights transfer towards N.Siberia via Scandinavia.

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/n16_amsu_z70_nh_asc.gif

supporting current trophospheric modelling of a cooler north westerly flow in early April and the prospect of heights in the N.Atlantic.

[Alex]

I'm assuming no change and we are heading into the final warming phase?

[summer blizzard]

Warming has only propogated own to 10hpa so far, so no final warming just yet.

[Weather-history]

This thread seems to have died.

Here's the temperature graphs for the 2011-12 season

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ts.php?plot=temps&alert=1&lng=eng

[492]

This thread seems to have died.

Here's the temperature graphs for the 2011-12 season

http://wekuw.met.fu-...alert=1&lng=eng

This is fascinating as the marked warming in early to mid January appeared to link directly to western moving block over northern Siberia later in the month. The Siberian high migrated westwards at around 60 to 65 N maintaining a central pressure of 1060HPA over a period of a week or more. The result was a very unusual outbreak of Siberian air over the southeast of the UK and intense cold over much of Europe. I would think that actual Siberian air reaching the UK is a very rare event indeed and has probably only occurred on one or two occasions in the last 100 years.

[AWD]

Around what time can we start looking at the Stratosphere for clues about winter 2012?

[chionomaniac]

I normally start a thread in November for the forthcoming winter but generally the extent ozone levels and cooling seen from October onwards can help determine the early season pattern. The QBO phase is a little more predictable now.

[summer blizzard]

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

Whilst the stratosphere will have very little effect until November it is perhaps interesting to note that it may have peaked for the year in the last few days.