Stratosphere Temperature Watch 2011/2012

[cooling climate]

Look at RJS winter forecast closely, one might see this fits

BFTP

Is that the one that has already gone pear shaped.

Think I will pass.

[Glacier Point]

Out of interest, I've plotted top ten -AO Jan/Feb periods and top ten +AO Jan/Feb periods (December - February data) to see if there is a variance with meridional surface flux anomalies.

Guess what.

-AO years:

+AO years:

In those two key areas, North Atlantic (Ocean Heat Flux) and western Siberia (increased Albedo), the flux anomalies are mirror images of each other in the opposite sign, as per the correlation in the study Chionomaniac cited and as we would expect for the two ends of the spectrum in terms of the AO state.

Going through the data, October doesn't seem significant. Patterns tend to show in November onwards. So, begs the question, how are we doing so far ? In terms of Siberia, no problem, plenty of snow there and more to come. In terms of the North Atlantic, latest available data:

Seems to suggest we are nicely placed and definately tilted towards the -AO years' pattern.

Data from

http://www.esrl.noaa.gov/psd/cgi-bin/DataAccess.pl?DB_dataset=NCEP+Reanalysis+Daily+Averages+Surface+Flux&DB_variable=Sensible+Heat+Net+Flux&DB_statistic=Mean&DB_tid=31987&DB_did=34&DB_vid=1249

[chionomaniac]

Thanks for doing that Stewart. Another reinforcement perhaps for your later winter forecast. It'll be worth checking again at the end of the month.

[Midlands Ice Age]

Out of interest, I've plotted top ten -AO Jan/Feb periods and top ten +AO Jan/Feb periods (December - February data) to see if there is a variance with meridional surface flux anomalies.

Guess what.

-AO years:

+AO years:

In those two key areas, North Atlantic (Ocean Heat Flux) and western Siberia (increased Albedo), the flux anomalies are mirror images of each other in the opposite sign, as per the correlation in the study Chionomaniac cited and as we would expect for the two ends of the spectrum in terms of the AO state.

Going through the data, October doesn't seem significant. Patterns tend to show in November onwards. So, begs the question, how are we doing so far ? In terms of Siberia, no problem, plenty of snow there and more to come. In terms of the North Atlantic, latest available data:

Seems to suggest we are nicely placed and definately tilted towards the -AO years' pattern.

Data from

http://www.esrl.noaa...=34&DB_vid=1249

I am an novice in this sphere but am following with interest.

I have noticed that two of the years appear in both positive and negative anomalies in the response by GP.

These are two interesting years 1969 and 1963. Is this correct? and if so does it mean that a switch occured during the period dec to feb?

1960 was cold year and 1963 was well we all know.

MIA

Tink this is very in

[Glacier Point]

I have noticed that two of the years appear in both positive and negative anomalies in the response by GP.

These are two interesting years 1969 and 1963. Is this correct? and if so does it mean that a switch occured during the period dec to feb?

1960 was cold year and 1963 was well we all know.

MIA

Tink this is very in

Fixed...

+AO years

[chionomaniac]

It's good to see healthier ozone forecasts. This is promising for later on in winter. Ozone appears to be forecast to build just south of 30N.

[kold weather]

Ceertainly an interesting link GP, that would certainly suggest a -ve AO for the second half of winter, I'm still worried that other factors are going to line up in such a way that any decent -ve AO will shoot cold into the wrong areas and we'll be in the 'milder zone' but thats rather difficult this far out to try and call and is of course always a risk.

Might be the case that we grab hold of whatever cold we can get through any inversions/topplers in the first half then watch the taps open and hope that any cold shot will be directed towards us rather then say E/C.Europe and W.Russia like I'm personally fearing will happen...

[karyo]

Might be the case that we grab hold of whatever cold we can get through any inversions/topplers in the first half then watch the taps open and hope that any cold shot will be directed towards us rather then say E/C.Europe and W.Russia like I'm personally fearing will happen...

Is there a reason for this fear?

Karyo

[Kentish Kiwi]

Out of interest, I've plotted top ten -AO Jan/Feb periods and top ten +AO Jan/Feb periods (December - February data) to see if there is a variance with meridional surface flux anomalies.

Certainly provides hope for the second half of winter.

Would it be possible to produce something similar in terms of NAO?

[Cecil Hogmanay Melchett]

Ceertainly an interesting link GP, that would certainly suggest a -ve AO for the second half of winter, I'm still worried that other factors are going to line up in such a way that any decent -ve AO will shoot cold into the wrong areas and we'll be in the 'milder zone' but thats rather difficult this far out to try and call and is of course always a risk.

Might be the case that we grab hold of whatever cold we can get through any inversions/topplers in the first half then watch the taps open and hope that any cold shot will be directed towards us rather then say E/C.Europe and W.Russia like I'm personally fearing will happen...

Hi Kold Which other factors are you worried about?

oh karyo my North west buddy beat me to it ;0

Edited November 16, 2011 by happy days

[BLAST FROM THE PAST]

Is that the one that has already gone pear shaped.

Think I will pass.

Hmmm, winter LRF pearshaped, .....? :blink: You take the prize

BFTP

Edited November 16, 2011 by BLAST FROM THE PAST

[chionomaniac]

Next attack imminent?

Let's see if there is any feedback into the stratosphere from this one.

[Glacier Point]

Unlikely I'd say Ed..

I suspect that it won't be much of a +MT given the state of angular momentum budgets (partiucular reference to frictional torque which is trending downward and usually preceeds mountain torrque), although the atmosphere does seem very keen to add westerlies over Asia.

Also a factor I think are the low heights fringing Greenland and lower tropospheric depressions skirting around the North Atlantic - vaguely recall how this lowered the tropopause and prevented wave breaking in the area and caused a rise in the tropopause over the North Pole effectively deflecting waves back into the middle latitude.

On a positive note, ozone levels look less bad, not as good as the last few years but better than 2007 at the same time. I suspect we'll see ozone totals increase as we enter the second half of December.

[Yorkshiresnows]

Hi G.P,

There is a lot of talk over on Weatherbell (Joe B and Joe D) concerning a pattern change early December (obviously this is skewed towards the US) though they are expecting a rise in heights over southern Greenland:

For a change the ensemble means provide a more realistic solution with the North Pacific cold trough with an axis extending south west of 150W. Note the warmth in northeast Canada and southern Greenland reflected a tendency for blocking. Also the nosing ridge feeding the Great Basin high which helps deflect cold air south the east.

The spaghetti chart which shows the 516, 546, 576 and 588 gpm height contours for each of the 21 ensemble members. Climatology is shown in green and ensemble mean in orange for those contours. White depicts the operational 18Z run. See how again the op run was an outlier. The majority of members are suggesting a central US trough which corresponds to the Pacific trough location anchor.

One of these days soon, the op runs will reflect a change colder late this month and early December.

BTW, this is the second straight GFS ensemble showing this tendency. It has more eastern Canada blocking.

See 16 of the individual members. Almost a third were impressively cold..

I note that the emphasis of these discussions are in relation to the US situation, but a pattern change nevertheless. Just wondered what your thoughts were or, if I have (most likely) latched onto the wrong end of the stick.

Interesting that the Weatherbell talk over recent days has been for December cold to begin to take hold (US) with a gradual cooling of central Europe into the NorthWest later ...... sounds possible this may be similar to your own thoughts but just a little sooner ?

Cheers

Y.S

[chionomaniac]

Unlikely I'd say Ed..

I suspect that it won't be much of a +MT given the state of angular momentum budgets (partiucular reference to frictional torque which is trending downward and usually preceeds mountain torrque), although the atmosphere does seem very keen to add westerlies over Asia.

Also a factor I think are the low heights fringing Greenland and lower tropospheric depressions skirting around the North Atlantic - vaguely recall how this lowered the tropopause and prevented wave breaking in the area and caused a rise in the tropopause over the North Pole effectively deflecting waves back into the middle latitude.

On a positive note, ozone levels look less bad, not as good as the last few years but better than 2007 at the same time. I suspect we'll see ozone totals increase as we enter the second half of December.

I think that any warming will skirt around the vortex as well, without any breakthrough. But each little warming can hopefully induce a feedback mechanism which will help later on in the season. I am thinking in terms of the ozone levels and changing of positioning of blocking.

I will search tonight for a paper that analysed the precursors for split and displacement SSW's that showed upper Atlantic or Pacific or both blocking patterns as preconditioning for later on. The pattern is in place now but I suspect we will need to see it in December. (Of course not every blocking pattern leads to stratospheric changes).

[lorenzo]

Can anyone point me towards other winters where the PV displayed high strength at its current position so i can compare Dec / Jan Evolutions?

[chionomaniac]

Can anyone point me towards other winters where the PV displayed high strength at its current position so i can compare Dec / Jan Evolutions?

That is difficult. One can look at the cpc charts regarding temperature anomalies or zonal mean wind anomalies but that doesn't indicate the vortex shape and position throughout those periods.

The sudden stratosphere warming website is currently offline until after Christmas - this gave a great idea of vortex shape prior to previous SSW's so we can't use that.

That was the best site to use when combined with the cpc stratospheric pages.

If we can get the Northern Annular Mode (NAM) readings at 150 hPa then we can use these to guestimate the future AO likelihood. Any forecast for the AO that uses this lower stratospheric information has an increased accuracy than those that use tropospheric readings alone.

Latest stratospheric polar vortex info here - http://www.columbia.edu/%7elmp/paps/waugh+polvani-PlumbFestVolume-2010.pdf

[ZONE 51]

An interesting study here -

The primary causes for the onset of major, midwinter, stratospheric sudden warming events remain unclear. In this paper, we report that 25 of the 27 events objectively identified in the ERA-40 dataset for the period 1957–2001 are preceded by blocking patterns in the troposphere.The spatial characteristics of tropospheric blocks prior to sudden warming events are strongly correlated with the type of sudden warming event that follows. Vortex displacement events are nearly always preceded by blocking over the Atlantic basin only, whereas vortex splitting events are preceded by blocking events occurring in the Pacific basin or in both basins contemporaneously. The differences in the geographical blocking distribution prior to sudden warming events are mirrored in the patterns of planetary waves that are responsible for producing events of either type. The evidence presented here, suggests that tropospheric blocking plays an important role in determining the onset and the type of warmings.

Here is the study in PDF - blocking and stratosphere warming.pdf

Edited November 18, 2011 by ElectricSnowStorm

[summer blizzard]

http://web.mit.edu/jlcohen/www/papers/CohenandJones_GRL11.pdf

AO to tank this winter?

[ZONE 51]

http://web.mit.edu/j...Jones_GRL11.pdf

AO to tank this winter?

That connection is what i have been studying/researching, there is mounting evidence on this connection with snow cover. and i expect for this reason alone then the AO is going to suddenly drop, i also think a SSW event is likely to happen especially January, with a significant amount of snowfall.

A slow progress into a cold and snowy winter..

Edited November 19, 2011 by ElectricSnowStorm

[Alan Robinson]

A slow progress into a cold and snowy winter..

According to the Danes, ECMWF are predicting that the mean temperature in Denmark for December to February inclusive will be 1.3 degrees above the seasonal norm at 1.8 degrees C. That will be no less than 3 degrees above the mean these last two winters, which were harsh.

http://www.dmi.dk/dmi/saesonprognose_udsigt_til_vintervejr

At the bottom of the article, the forecaster actually says seasonal forecasts have lost much credibility in recent times, but the good news is that seeing how almost everyone uses the same data from Reading, then the profession is wrong en masse. Do you mind if I forward to him your post here for his consideration?

[karyo]

Stratospheric temperatures continuing on the colder than average route!

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ts.php

Karyo

[chionomaniac]

An interesting study here -

Here is the study in PDF - blocking and stratosphere warming.pdf

That was the paper I was looking for! Thanks ESS.

[bobbydog]

That was the paper I was looking for! Thanks ESS.

hi chiono, what do you make of that study? considering there has been sustained blocking in the pacific lately

[summer blizzard]

Just curious but if you get an SSW with an active MJO, would this tend to amplify the effect if in the correct phases?

Not thinking as much as last December but maybe something approaching January or February 2010.

I also note that the QBO at 50mb actually saw a value of +11, has this been dropping or continuing to rise.