Stratosphere Temperature Watch 2012/2013

[Gavin Hannah]

Lag time of 4-6 weeks from a ssw not from a little bit of warming. We have not had a ssw, so far too early to set the egg timer for 6 weeks...

I'll keep it on standby just incase.

[Suburban Streamer]

Some great posts and links over the past couple pages - thanks to everyone.

Unfortunately the lag time between me reading and me understanding is about 150 years!

[greybing]

to 'iBringTheHammer',I like the poem.

[chionomaniac]

Latest MJO analysis show we are now entering phase 1 and the forecasts still stick with a large amplitude event.

http://www.cpc.ncep....clivar_wh.shtml

So we would expect to see some kind of warming 10 days hence as part of the feedback cycle.

Latest 11 day 12Z 30 hPa forecast courtesy of NW extra:

OOH whats that there?

[A Winter's Tale]

Latest MJO analysis show we are now entering phase 1 and the forecasts still stick with a large amplitude event.

http://www.cpc.ncep....clivar_wh.shtml

So we would expect to see some kind of warming 10 days hence as part of the feedback cycle.

Latest 11 day 12Z 30 hPa forecast courtesy of NW extra:

OOH whats that there?

Hi C, I'm wondering what effect would a warming have on the pressure patterns for the NH at this early stage in the season.

[chionomaniac]

Hi C, I'm wondering what effect would a warming have on the pressure patterns for the NH at this early stage in the season.

The pressure patterns in the NH would in some way be responsible for this in the first place.

It is far too early to do anything other than monitor presently, after all this could all change in the next run and I wouldn't want to give the wrong impression out.....

[lutfishah]

South Pole 30 hpa warming.

[feb1991blizzard]

South Pole 30 hpa warming.

Probably a final warming.

[Gavin Hannah]

to 'iBringTheHammer',I like the poem.

A community effort created by several members.

[ZONE 51]

Found something interesting here:

In January 2009 and 2010, two major stratospheric warmings (MSWs) took place in the boreal polar stratosphere. Both MSWs were preceded by nearly the strongest injection of tropospheric wave activity on record since 1958 and their central date was almost coincident. However, the typical external factors that influence the occurrence of MSWs (the Quasi-Biennial Oscillation, sunspot cycle, or El Niño) were dissimilar in the two midwinters: favorable in 2010 but unfavorable in 2009. In this study, the driving mechanisms of these two different MSWs were investigated focusing on the amplification of upward wave activity injection into the stratosphere before the MSW onset. By decomposing the total wave flux injection into contributions from the climatological planetary waves and from deviations from the latter we found clear differences in this amplification between both MSWs. The pre-MSW period in 2009 was characterized by a peak in the 100 hPa eddy heat flux with a predominance of wave number 2 activity. This was due to strong anomalies associated with Rossby wave packets originating from a deep ridge over the eastern Pacific. In contrast, the amplification of the upward wave propagation prior to the 2010 MSW was equally due to Rossby wave packets and to the interaction between the latter and the climatological waves. This amplification enhanced wave number 1 stationary waves in January 2010, which seemed at least partially due to the 2009/2010 El Niño event. Our results show the relevance of the internal tropospheric variability in generating MSWs, particularly when the external factors do not play any role.

http://www.agu.org/pubs/crossref/2011/2010JD015023.shtml

[Mark Neal.]

Am not experienced, bold, crazy* enough (delete as applicable) to make any kind of public prediction for Winter Mark, will leave that to the folks with much better expertise who can provide a more qualified analysis and explanation.. Matt, Chiono, GP, S Murr to name a few.

I enjoy crunching through data and papers for clues and learning - cannot deny the excitement and the potential for this Winter to deliver some exceptional weather. As for when who knows !!

Okay. Thanks for replying, I have enjoyed reading the posts in here and it is interesting with all these charts and Analysis you learn new stuff each day. Keep up the great work Chio,GP,Lorenzo Etc.. I will be glued over coming weeks and months ahead for sure!

[MattH]

Just a quick one and to continue to wet the appetite, but the monthly update of the EUROSIP (some info on it here - http://t3projects.zmaw.de/uploads/media/TStockdale.pdf) seasonal model for October which combines the ECMWF, Met Office and MeteoFrance data, does signal higher pressure to the N and NW of the UK as a +ve pressure anom throughout D/J/F. It isn't a strong signal, but compared with the ECMWF seasonal it is totally different and supports a far more blocked pattern to the N and NW of the UK in particular throughout the winter. The average temperature for the UK is approx 0.5C to 1C below average according to this model as well, but I would take that with a decent pinch of salt.

The broader importance is the signal for higher pressure in the 'right' areas...

Interesting times.

M.

[Gavin Hannah]

Just a quick one and to continue to wet the appetite, but the monthly update of the EUROSIP (some info on it here - http://t3projects.zm.../TStockdale.pdf) seasonal model for October which combines the ECMWF, Met Office and MeteoFrance data, does signal higher pressure to the N and NW of the UK as a +ve pressure anom throughout D/J/F. It isn't a strong signal, but compared with the ECMWF seasonal it is totally different and supports a far more blocked pattern to the N and NW of the UK in particular throughout the winter. The average temperature for the UK is approx 0.5C to 1C below average according to this model as well, but I would take that with a decent pinch of salt.

The broader importance is the signal for higher pressure in the 'right' areas...

Interesting times.

M.

Clearly illustrated on the 00Z GFS run this morning, albeit, in deep FI.

[bluearmy]

Clearly illustrated on the 00Z GFS run this morning, albeit, in deep FI.

Deep fi on gfs 00z is end october and more than four weeks away from december which is the commencement of the anomoly charts matt speaks about. the only relevance of current NWP modelling to this thread is what effect it may have on the strat going forward which then may have a consequential effect on the trop. we shouldnt get ahead of ourselves on this thread re currrent modelling of the trop.

notice a gfs op fi tendency to raise 10 hpa temps somewhat over central siberia. Beyond 10 days so not cross checkable with ecm yet.

[Glacier Point]

Indeed Nick, this has been a recurrent theme.

Also cropping up as a trend is for 30hPa temps to warm a touch around Canada and lop-sided appearance to the polar temperature profile with coldest temps (around seasonal average) to be located over NE Atlantic / eastern Greenland. What that gives us is an interesting prospect across 90N with relatively warmer temperatures just to the west.

Zonal winds still very weak across 70N, although a marginal (brief?) increase forecast through days 8-10.

[shedhead]

Deep fi on gfs 00z is end october and more than four weeks away from december which is the commencement of the anomoly charts matt speaks about. the only relevance of current NWP modelling to this thread is what effect it may have on the strat going forward which then may have a consequential effect on the trop. we shouldnt get ahead of ourselves on this thread re currrent modelling of the trop.

notice a gfs op fi tendency to raise 10 hpa temps somewhat over central siberia. Beyond 10 days so not cross checkable with ecm yet.

Spot on ba... one or two on here could already do with drawing breath and resist the temptation to get to far ahead of themselves. Encouraging signs yes, but nothing more at this stage, with still a very long way to go before anything becomes even remotely backable regarding this small island.

Edited October 16, 2012 by shedhead

[sebastiaan1973]

I found this piece about the SAI.

Mid-month October update on Eurasia snow cover. The plot shows snow cover from 0 to 180 E, 25N to 60N. This matches the domain in Judah Cohen's 2011 paper.

The red line is 2009 (which had a -AO the following winter) and the blue line is 2007 (which had a +AO the following winter). Cohen's 15 year data set has a correlation of 0.86 between snow advance and the following winter's AO.

This year, in green, has had what I believe to be an ideal start. If snow cover explodes in the second half of the month, then I'm on the bandwaggon for a deep -AO this winter. Most of the snow cover this year has been in eastern Eurasia. However, the GFS ensembles show a great deal of storminess in western Eurasia toward the end of the month which would be fantastic for anomalous snow extent.

http://www.americanw...25#entry1791017

Edited October 16, 2012 by sebastiaan1973

[chionomaniac]

Stage 1

70hpa today:

70 hPa T+240

A slight warming forecast - but too small to be significant.

And again T+240 from today

And at 30 hPa

Just as expected so far.

And edit for those looking in - this is nothing to do with a SSW - but monitoring lower strat temperatures following MJO phase 1

Edited October 16, 2012 by chionomaniac

[lorenzo]

Didn't spy this at a glance through the papers thread, it might already be in there. Linking this in as it touches on October Eurasian snow cover as per Seb post above and also differentiates between the positioning of the Pacific Low. Stewart illustrated October here.

From the conclusion section..

A low over the North Pacific tends to result in a dramatic increase in wave 1 leaving the troposphere and converging at the vortex, and a high over eastern Europe tends to result in a dramatic increase in wave 2 leaving the troposphere

and converging at the vortex. A low over the northwestern Pacific (possibly associated with October Eurasian

snow) has a similar, but weaker, effect than that of a low over the central Pacific.

In particular, an eastern European high and North Paciï¬c low appear to weaken the upper stratospheric vortex shortly after the anomaly at the surface, and the influence seemingly propagates downward over the next month. No significant differences between early winter and late winter are apparent. The dominant pathway through which ENSO modulates the vortex is, ostensibly, its North Paciï¬c teleconnection. Most of the variance of the polar vortex associated with October Eurasian snow can be traced back to the northwestern Paciï¬c, QBO, and eastern Europe.

GHetal10.pdf

[Catacol]

Didn't spy this at a glance through the papers thread, it might already be in there. Linking this in as it touches on October Eurasian snow cover as per Seb post above and also differentiates between the positioning of the Pacific Low. Stewart illustrated October here.

From the conclusion section..

A low over the North Pacific tends to result in a dramatic increase in wave 1 leaving the troposphere and converging at the vortex, and a high over eastern Europe tends to result in a dramatic increase in wave 2 leaving the troposphere

and converging at the vortex. A low over the northwestern Pacific (possibly associated with October Eurasian

snow) has a similar, but weaker, effect than that of a low over the central Pacific.

In particular, an eastern European high and North Paciï¬c low appear to weaken the upper stratospheric vortex shortly after the anomaly at the surface, and the influence seemingly propagates downward over the next month. No significant differences between early winter and late winter are apparent. The dominant pathway through which ENSO modulates the vortex is, ostensibly, its North Paciï¬c teleconnection. Most of the variance of the polar vortex associated with October Eurasian snow can be traced back to the northwestern Paciï¬c, QBO, and eastern Europe.

GHetal10.pdf

Brilliant article - thank you. I got lost in large parts in the middle, but the opening section and conclusions were very clear. From here on in I will keep a close hopeful eye in Nov/Dec for a low pressure in the central northern pacific and high pressure in Russia/Siberia, particularly in an easterly QBO phase!

[chionomaniac]

There are the first signs of wave activity breaking into the stratosphere that will be encouraging down the line, Waves breaking into the upper stratosphere are important in the aiding of an efficient BDC transporting ozone from the tropics. So far we have seen an efficient process occurring to the south pole over the last few months, suggesting that the ozone was there, now we need to see the same occurring in the NH.

The large scale planetary wave system this time is of the one wave variety which causes a slight displacement of the polar vortex.

Wave number 1 increased activity:

When we look at the 10 hPa chart we see the slight displacement and how this allows some warmer temperatures into the polar regions:

If this continues then I would expect a weak pressure rise over the Pacific sector - something hinted at by the GFS

As ever this is early days but it is this type of thing that we should look for when studying the mid levels of the stratosphere.

On another note we are still seeing the warming forecast for the lower stratosphere that we are monitoring following the increase in amplitude of phase 1 MJO activity.

What we are looking at are all piece of a full atmospheric jigsaw that will be interlinked with the tropospheric GWO and feeding back through the stratosphere.

Edited October 17, 2012 by chionomaniac

[Glacier Point]

Didn't spy this at a glance through the papers thread, it might already be in there. Linking this in as it touches on October Eurasian snow cover as per Seb post above and also differentiates between the positioning of the Pacific Low. Stewart illustrated October here.

From the conclusion section..

A low over the North Pacific tends to result in a dramatic increase in wave 1 leaving the troposphere and converging at the vortex, and a high over eastern Europe tends to result in a dramatic increase in wave 2 leaving the troposphere

and converging at the vortex. A low over the northwestern Pacific (possibly associated with October Eurasian

snow) has a similar, but weaker, effect than that of a low over the central Pacific.

In particular, an eastern European high and North Paciï¬c low appear to weaken the upper stratospheric vortex shortly after the anomaly at the surface, and the influence seemingly propagates downward over the next month. No significant differences between early winter and late winter are apparent. The dominant pathway through which ENSO modulates the vortex is, ostensibly, its North Paciï¬c teleconnection. Most of the variance of the polar vortex associated with October Eurasian snow can be traced back to the northwestern Paciï¬c, QBO, and eastern Europe.

GHetal10.pdf

We can visualise this if we take the ten most negative AO winters and subtract H5 anomalies from the top ten most positive AO winters. For the preceeding November, the reanalysis depicts the teleconnective importance of the Aleutian Low and east European High. This could be described as a 'predictor' pattern for a negative AO for the following winter.

[Glacier Point]

There are the first signs of wave activity breaking into the stratosphere that will be encouraging down the line, Waves breaking into the upper stratosphere are important in the aiding of an efficient BDC transporting ozone from the tropics. So far we have seen an efficient process occurring to the south pole over the last few months, suggesting that the ozone was there, now we need to see the same occurring in the NH.

The large scale planetary wave system this time is of the one wave variety which causes a slight displacement of the polar vortex.

Wave number 1 increased activity:

What we are looking at are all piece of a full atmospheric jigsaw that will be interlinked with the tropospheric GWO and feeding back through the stratosphere.

Interestingly the paper above links an Alaskan ridge to strong wave 1 activity.

[chionomaniac]

I did add onto my last post before it crashed that I think that we will see a positive Asian MT in the next five days which will be part of the jigsaw feed back system following a trough passing through the Mongolian plateau.

[chionomaniac]

We need something to break the temperatures cooling in the mid stratosphere and as mentioned yesterday there is an increase in wavenumber 1 activity that I suspected would increase in amplitude. There is a slight increase forecast and this has had an impact on the 10 hPa temperature forecast. Only a very little presently - but compared to yesterday - an improvement..