Jump to content
Snow?
Local
Radar
Cold?

Stratosphere Temperature Watch 2012/2013


chionomaniac
 Share

Recommended Posts

Spotted a post you think may be an issue? Please help the team by reporting it.
Posted
  • Location: Berkshire
  • Location: Berkshire

    Are there records of SSW indices anywhere (or proxy indicators)?

    I feel a little bit of number crunching if anyone can source some.

    Thanks.

    Edited by muppet77
    Link to comment
    Share on other sites

    Posted
  • Location: OSLO, Norway
  • Weather Preferences: Snow, Storms, Heat, Thunderstorms
  • Location: OSLO, Norway

    Although the positioning and strength of these, there are consistently further warmings showing up on the 10hpa strat GFS runs. I like.

    Posted Image

    Link to comment
    Share on other sites

    Posted
  • Location: North Carolina
  • Weather Preferences: Warm sunny days
  • Location: North Carolina

    post-12276-0-40650600-1356784922_thumb.p

    I honestly struggle to see how the stratospheric vortex will be maintained by the end of January- Brickfielder's post a while back highlighted the different scenarios, it's possible we could go through them all- propagation into the tropo-vortex would then become the crux of the analysis in the next few weeks

    `

    It's having one last laugh now, but it's about to get torn apart... whether we get lucky or not is another question, but isn't it fun watching it crumble alone?!

    This is a displacement SSW right? just want to make sure I am getting this right.

    Link to comment
    Share on other sites

    Posted
  • Location: North Carolina
  • Weather Preferences: Warm sunny days
  • Location: North Carolina

    post-12276-0-40650600-1356784922_thumb.p

    I honestly struggle to see how the stratospheric vortex will be maintained by the end of January- Brickfielder's post a while back highlighted the different scenarios, it's possible we could go through them all- propagation into the tropo-vortex would then become the crux of the analysis in the next few weeks

    `

    It's having one last laugh now, but it's about to get torn apart... whether we get lucky or not is another question, but isn't it fun watching it crumble alone?!

    BTW can we use this graphic for a blog? How should we credit it if so?

    Link to comment
    Share on other sites

    Posted
  • Location: New Ash green 150M / 500 FT
  • Location: New Ash green 150M / 500 FT

    You will only need to blog models- you can reanalise any chart for any day for the strat back to 1948-

    S

    Link to comment
    Share on other sites

    Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

    Just by viewing these temperature charts we can see the warming filtering down to the lower levels

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

    with consequent reduction and then reversal in the Zonal Winds

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

    Good to see the warming getting down to the trophosphere by day 10.

    Link to comment
    Share on other sites

    Posted
  • Location: hertfordshire
  • Location: hertfordshire

    A couple of thoughts as we stand on the brink of a major mid winter warming..

    The last few GFS runs have pointed towards a large junk of the residual split vortex centred initially over Hudson Bay with a general trend to retrogress this as the entire upper and middle stratosphere demonstrates a negative (westward) gyre. 12z t300 a good depiction of this.

    post-2478-0-31966600-1356815181_thumb.jp

    That suggests a large poleward flux of ozone through the North Atlantic around the eastward flank of the cut off vortex from the mid and low latitudes as colder air is pulled into the tropical stratosphere. The last few runs indicating warming around Greenland are consistent with ozone flux.

    The question arises how quick if any will the propagation be of -ve zonal wind anonalies ?

    I suspect the answer to this may be quicker than a conventional event given the state of the atmosphere ahead of the warming lower down in the mid and lower stratosphere and troposphere and the trospheric longwave pattern projected days 11-15.

    If we look at zonal wind anomalies there is a persistence of -ve zonal wind anomalies.

    post-2478-0-85609700-1356815108_thumb.jp

    That means less wind shear for any wave working its way down.

    The programmed GEFS mean height anomaly pattern for days 11-15 depicts a developing -ve EPO pattern with a ridge over the NE Pacific extending into Alaska and troughing into the mid West USA and Canada with +ve heights over the mid Atlantic.

    post-2478-0-64735100-1356815136_thumb.jp

    That largely coincides with the 10hPa GPH forecast for around day 13, meaning that the trosphere doesn't have to move much towards the upper level flow.

    An instant tropospheric reaction to the warming is possible, but perhaps we should be focussing more around days 10-14 following the warming (5th Jan) for the first real impact ?

    That would also be my interpretation for the first real impacts on the 500 synoptics which would roughly

    take us to the 15th-20th and by which time we could as you say be in quite a favorable position from

    the off.

    I must admit the prospects are quite mouth watering but to early in the day for any serious speculation.

    Edited by cooling climate
    Link to comment
    Share on other sites

    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    I still feel that the 500 mb charts will start to show a marked change in the pattern from that currently in about 2-3 days time. So I would suspect, using my very simplified idea from the Stratosphere spike of 23 December, that by 14-17 January we MAY see blocking starting to show up.

    • Like 2
    Link to comment
    Share on other sites

    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    Wonderful wonderful trend in FI tonight. That warming over Greenland in the split displaced vortex couldn't be better positioned. How close will the forecast be to verification I wonder.

    http://nwstatic.co.uk/viewimage.pbx?type=gfs;date=20121229;time=18;ext=384;file=npst10;sess=a4811469fcc97c4e3d2740800927b9bb;

    I sense that the model thread will be getting busy again............

    • Like 5
    Link to comment
    Share on other sites

    Posted
  • Location: st albans
  • Location: st albans

    Wonderful wonderful trend in FI tonight. That warming over Greenland in the split displaced vortex couldn't be better positioned. How close will the forecast be to verification I wonder.

    http://nwstatic.co.uk/viewimage.pbx?type=gfs;date=20121229;time=18;ext=384;file=npst10;sess=a4811469fcc97c4e3d2740800927b9bb;

    I sense that the model thread will be getting busy again............

    Something i have noticed is the temp forecast tend to be pretty consistent in general locale but the heights forecast varies run to run after approx day 11.

    Link to comment
    Share on other sites

    Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

    The latest ECM run has the SSW on the 5th, with mean windspeeds a little slower than previous runs, but nevertheless still easterlies.

    http://maidenerleghw...r.com/strat.php

    Very very nearly a technical SSW on the 4th ! Nice to see the consistency in the forcast though. It's been showing as the 5th, give or take a day or two, for quit a while now and never really wavered.

    Edited by s4lancia
    Link to comment
    Share on other sites

    Posted
  • Location: Netherlands
  • Location: Netherlands

    I think it's quite remarkable we get a SSW. Posted Image

    Recent studies have suggested that El Niñoâ€Southern Oscillation (ENSO) may have a considerable impact on

    Northern Hemisphere wintertime stratospheric conditions. Notably, during El Niño the stratosphere is warmer than

    during ENSOâ€neutral winters, and the polar vortex is weaker. Oppositeâ€signed anomalies have been reported during

    La Niña, but are considerably smaller in amplitude than during El Niño. This has led to the perception that El Niño is

    able to substantially affect stratospheric conditions, but La Niña is of secondary importance. Here we revisit this

    issue, but focus on the extreme events that couple the troposphere to the stratosphere: major, midâ€winter stratospheric

    sudden warmings (SSWs). We examine 53 years of reanalysis data and find, as expected, that SSWs are nearly twice

    as frequent during ENSO winters as during nonâ€ENSO winters. Surprisingly, however, we also find that SSWs

    occur with equal probability during El Niño and La Niña winters. These findings corroborate the impact of ENSO on

    stratospheric variability, and highlight that both phases of ENSO are important in enhancing stratosphereâ€troposphere

    dynamical coupling via an increased frequency of SSWs. http://www.columbia.edu/~lmp/paps/butler+polvani-GRL-2011.pdf

    • Like 5
    Link to comment
    Share on other sites

    Posted
  • Location: st albans
  • Location: st albans

    Just the thought that the current two week upper strat height pattern could be showing in the trop by the end of jan is mouth watering.

    The last few runs do show the colder strat temps putting up a better fight than looked likely post displacement until a second warming comes in to split the remnant before it can attempt to push back towards the pole. This does show that the forecast post T300 cannot be taken for granted. I assume in a post SSW scenario, verification would drop somewhat at two week range ??

    Link to comment
    Share on other sites

    Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

    Just been reading through some of research into SSW's and some interesting results pop up re propogation.

    Firstly the propogation downward into the troposphere is much more likely if the NAM or otherwise known AO is either neutral or positive initially.

    I suppose this is logical given that we could view the PV as a balloon, fully inflated, theres more air to release, less inflated less.

    Another interesting thing I read,a sharp reversal of zonal winds at the 10hPa level doesn't guarantee a strong response from the troposphere.

    The research suggested its lower in the stratosphere that has more impact on the troposphere.

    These may have been covered previously but I thought I'd just add them in here.

    Heres the link to one of the research papers:

    http://cims.nyu.edu/~gerber/pages/documents/gerber_orbe_polvani-GRL-2009.pdf

    Edited by nick sussex
    • Like 6
    Link to comment
    Share on other sites

    Posted
  • Location: St Albans, 95m asl
  • Location: St Albans, 95m asl

    Another run, another secondary warming, this time more concentrated on Greenland/NE Canada, but continues right through until the end of the run.

    Posted Image

    The aleutian low potential also there once again down the line, promising further wave breaking activity

    SK

    • Like 3
    Link to comment
    Share on other sites

    Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

    Yes an increasingly split vortex being modelled on this run chaps-100hPa at days 5,10 and 15

    post-2026-0-72209700-1356888529_thumb.pnpost-2026-0-74771100-1356888538_thumb.pnpost-2026-0-28185600-1356888548_thumb.pn

    It doesn`t look like cross-polar ridging yet but a nice gap opening up around Greenland/Iceland for some height rises as you suggest Ed.

    It looks more likely that we can get a complete split further on though if more wave breaking does occur.

    Edited by phil n.warks.
    • Like 2
    Link to comment
    Share on other sites

    Posted
  • Location: Portugal, Fátima
  • Location: Portugal, Fátima

    And while on the topic of cold and snow, the GFS and ECMWF models show significant stratospheric warming across the North Pole and Canada towards the middle of January. With the NAO expected to fall rapidly at that time, and with the AO expected to rise rapidly at that time, it's about to get very cold for many across the United States. The split & temporary collapse of the polar vortex we've seen in recent years has been interesting.. Considering it tends to happen after solstice, one of these years it's not going to set back up for the rest of winter. http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2319#yourcomment

    • Like 1
    Link to comment
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
     Share

    ×
    ×
    • Create New...