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Stratosphere Temperature Watch 2012/2013


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Posted
  • Location: Catchgate, Durham,705ft asl
  • Location: Catchgate, Durham,705ft asl

    Sorry to be a pain again, but it would be nice for an update on how the strat is and whether there is any further warming or wave breaking happening.

    Many thanks in advance.

    I'm sure others can give more info,but the SSW is an ongoing event with negative zonal winds

    at 60N 10 hpa right through the ECM forecast again.

    Institute of Meteorology: Physics of the Middle Atmosphere - ECMWF analyses and forecasts: January 13 2013 12 UTC

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    Steve whilst I agree to a certain extent, more especially with regards to the difficulty in forecasting exact placement of tropospheric synoptics (particularly with regard to the UK in the overall sch

    Posted Images

    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

    Posted Image

    I know its FI but this is the best 30mb FI chart from the GFS for a while.

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    Posted
  • Location: Edinburgh (previously Chelmsford and Birmingham)
  • Weather Preferences: Unseasonably cold weather (at all times of year), wind, and thunderstorms.
  • Location: Edinburgh (previously Chelmsford and Birmingham)

    Posted Image

    I know its FI but this is the best 30mb FI chart from the GFS for a while.

    I hope it comes off, anything to get that vortex segment well clear from Greenland would be excellent.

    Edited by 22nov10blast
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    But notice the very high skill score of the 10 day forecasts, prior to the SSW, where there is much less complex dynamics. And that is what I was telling about the power of the model stratosphere forecasts in the 240h-300h period, compared to tropospheric reliability.

    Yes, this predictability of the stratosphere shortly before the SSW has been noted in studies eg Gerber, Orbe & Polvani (2009).

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

    Just looking at the ECM mean Zonal winds through the levels out to day 10 and notice sporadic weak positive forecasts at 500hPa out to day 10

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

    Would assume this is why we are seeing the trophospheric modelling of only weak heights over the polar regions at present.

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    Posted
  • Location: Headington,Oxfordshire
  • Weather Preferences: Snow
  • Location: Headington,Oxfordshire

    Interesting article from BBC Weather forecaster John Hammond... '

    Sudden stratospheric warming responsible for UK's icy blast http://www.bbc.co.uk/weather/features/20998895. Its fantastic to see the Stratosphere now being mentioned in the public domain much more, Chiono ,GP, should be pleased!

    Edited by Mark Neal.
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    Posted
  • Location: E Lancs, 900ft asl
  • Weather Preferences: Snow, blizzards, cold, thunderstorms, frosts, fog, general extreme weather
  • Location: E Lancs, 900ft asl

    More interesting stratospheric charts today.

    So, so far this winter we have seen early tropospheric wave breaking into the lower strat whilst simultaneously the mid strat has cooled dramatically. A massive increase in wave 1 activity then has led to a displacement SSW and this has immediately been followed by an increase in wave two activity leading to a split vortex and another warming. And that is pretty much where we are today.

    Looking at the 10 hPa charts we see a strong Canadian vortex with a weker Siberian vortex in situ with a ridge keeping them apart.

    post-4523-0-41249600-1358240600_thumb.pn

    BY day three the Canadian vortex comes under further attack and weakens further increasing the strength of the ridge:

    post-4523-0-11783900-1358240711_thumb.pn

    The net result at 100 hPa is that the ridge displaces somewhat towards the Atlantic sector but not fully, and critically there is a developing Greenland ridge in place at this level by day 5.

    post-4523-0-61409500-1358240933_thumb.pn

    The net result is that any tropospheric trough trying to cross the Atlantic is likely to weaken and be displaced on a more southerly track - perhaps even more so then we have seen on the tropospheric model output so far.

    And behind this is there a possiility that tropospheric Greenland heights are being under estimated? (Remember Cohen?)

    So does a strong Atlantic trough fit in with the MJO phases?

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

    Errr, no not at all - the MJO is showing signs that it will move into phase 7 which the anomaly suggests the outlook is this:

    post-4523-0-72726600-1358241339_thumb.gi

    A stonking Atlantic ridge - compare this to the GFS ensemble mean anomaly chart:

    post-4523-0-44059800-1358241472_thumb.gi

    Unable to get ECM ones but the earlier output suggested better ridging.

    So my thoughts - well I think that the GFS is overplaying the strength of the mid Atlantc ridge some what. Yes we are likely to see some energy cross the Atlantic however this is likely to be followed by pressure rises behind linking up with the retrogressing high and a strong greenland block to develop after.

    So any breakthrough is likely to be either temporary, non existant, or limited to the very south followed by a blocked Atlantic.

    This is then going to allow one mighty cold blast from the NE get jolly close to the UK!!!!!

    Thanks Ed, appreciated, was going to try and run through a few charts myself as its been rather quite here, but as ever that answers my questions! As an additional note the EC32 maintains a signal for higher than average pressure over Greenland and the North Pole in general really throughout the forecast period but it also signals a particularly -ve pressure anom across and to the W of the UK signalling a particularly cyclonic and 'active' mid and eastern Atlantic and into the UK. Clearly whether this occurs or not I don't know, but it is attempting to model lows on a more southerly track, but overall the EC32 day doesn't paint a particularly cold outlook towards the end of January with temps forecast to rise to near average. Clearly it'll be interesting to see whether it is way off or not.

    I can't but help think that if we do get the scenario you describe then we are really looking at a prolonged period of cold weather for the UK and potentially very cold if that N or NE'ly flow can be achieved. It's interesting to note that some of the recent GFS ENS are particularly cold later in the month. All to play for throughout the second half of the winter and I certainly believe there is little chance of the vortex restrengthening or returning to a more organised state, enough to affect the troposphere.

    One question I have for you, which reply when you get chance is as follows;

    What variables evident did you acknowledge or know to look for weeks in advance to give you a solid grounding to suggest that a SSW would occur in January?. I remember this being mentioned way back in early to mid-December at a time when the ECMWF charts were clearly not even touching late December, let alone early January and the GFS model may have only been reaching late December as well?.

    What is fascinating here is that whilst we all acknowledge the conditions in the stratosphere are more 'stable' than that in the troposphere I would be interested to hear your thoughts, detailed if possible, as to what was being acknowledged at the start of the winter to gauge the event we have just experienced. I am certainly playing 'catch up' here in terms of what signs and signals to look for on a longer term basis.

    Regards and thanks in advance.

    M.

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    Posted
  • Location: Aberdeen
  • Weather Preferences: Stratosphere, Thunderstorms, Hurricanes, Snow Prediction
  • Location: Aberdeen

    Once again, very good post chiono!

    Would it be fair to say that the cold snowy event we're experiencing just now is a result of the first strat warming that happened at the start of Dec '12?

    Thanks,

    Stephane

    Edited by FrenchScotPilot1
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    Posted
  • Location: Almeirim de Fazendas, Portugal
  • Location: Almeirim de Fazendas, Portugal

    More interesting stratospheric charts today.

    So any breakthrough is likely to be either temporary, non existant, or limited to the very south followed by a blocked Atlantic.

    This is then going to allow one mighty cold blast from the NE get jolly close to the UK!!!!!

    Thanks for that - it provides good reason to increase hopes that the fuel supply coming out of Canada will be switched off, as the longer that the remaining Canadian segment of vortex lasts, then the greater chance that the jet stream would be lifted north as lows follow one after another across the atlantic. A little patience required to see this process reducePosted Image

    It strikes me that the ECM 32 day outlook hasn't picked up on any of these latest stratospheric signals yet and hence sees the continued cyclogenesis as I described and explains the rather more average end to January it suggests

    Edited by Tamara Road
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    Posted
  • Location: st albans
  • Location: st albans

    matt - i think the SSW prediction was made looking at likely wave 1 and wave 2 activity following hemispheric ridge/trough placement in late november/early december in conjunction with the already precarious nature of the strat vortex at the time. stewart had already predicted something like this based on forcast anomolys and feedback re eurasian snowcover oct/nov.

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    Posted
  • Location: Weston-S-Mare North Somerset
  • Weather Preferences: Hot sunny , cold and snowy, thunderstorms
  • Location: Weston-S-Mare North Somerset

    Thanks Chio

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    The one thing counteracting a weakened Atlantic is that we are approaching the period of strongest average NAO. The graph below shows that during most of the year there is a relationship between the AO and NAO but in the latter part of January and through February they diverge, with the NAO reaching a peak on 12th February, two days before the minimum AO.

    post-2779-0-03045200-1358260780_thumb.gi

    Though of course the circulation is affected by the SSW this underlying average pattern is still visible post SSW as shown in this graph of January-March NAO following SSWs.

    post-2779-0-65747800-1358261023_thumb.gi

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    Posted
  • Location: Crowborough, East Sussex 180mASL
  • Location: Crowborough, East Sussex 180mASL

    The one thing counteracting a weakened Atlantic is that we are approaching the period of strongest average NAO. The graph below shows that during most of the year there is a relationship between the AO and NAO but in the latter part of January and through February they diverge, with the NAO reaching a peak on 12th February, two days before the minimum AO.

    post-2779-0-03045200-1358260780_thumb.gi

    Though of course the circulation is affected by the SSW this underlying average pattern is still visible post SSW as shown in this graph of January-March NAO following SSWs.

    post-2779-0-65747800-1358261023_thumb.gi

    That looks like a good case for showing the error between the main NWP models and reality during and preceding the run run up to an SSW. i.e. the models cannot resolve the correct solution.

    Be aware that the AO and NAO index prediction is based on standard NWP output and so forward looking cannot be relied on in this situation.

    ffO

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    That looks like a good case for showing the error between the main NWP models and reality during and preceding the run run up to an SSW. i.e. the models cannot resolve the correct solution.

    Be aware that the AO and NAO index prediction is based on standard NWP output and so forward looking cannot be relied on in this situation.

    ffO

    Just to clarify, the graphs aren't NWP prediction, they are climatological averages since 1950 for all years, then specifically following an SSW.

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

    Reading uni strat data page.

    http://www.met.readi...iagnostics.html

    Also latest paper abstract with further evidence of tropospheric changes following SSW's.

    http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1698.html

    Edited by chionomaniac
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    Posted
  • Location: Netherlands
  • Weather Preferences: Hot summer, Cold winter
  • Location: Netherlands

    More interesting stratospheric charts today.

    So, so far this winter we have seen early tropospheric wave breaking into the lower strat whilst simultaneously the mid strat has cooled dramatically. A massive increase in wave 1 activity then has led to a displacement SSW and this has immediately been followed by an increase in wave two activity leading to a split vortex and another warming. And that is pretty much where we are today.

    Looking at the 10 hPa charts we see a strong Canadian vortex with a weker Siberian vortex in situ with a ridge keeping them apart.

    post-4523-0-41249600-1358240600_thumb.pn

    BY day three the Canadian vortex comes under further attack and weakens further increasing the strength of the ridge:

    post-4523-0-11783900-1358240711_thumb.pn

    The net result at 100 hPa is that the ridge displaces somewhat towards the Atlantic sector but not fully, and critically there is a developing Greenland ridge in place at this level by day 5.

    post-4523-0-61409500-1358240933_thumb.pn

    The net result is that any tropospheric trough trying to cross the Atlantic is likely to weaken and be displaced on a more southerly track - perhaps even more so then we have seen on the tropospheric model output so far.

    And behind this is there a possiility that tropospheric Greenland heights are being under estimated? (Remember Cohen?)

    So does a strong Atlantic trough fit in with the MJO phases?

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

    Errr, no not at all - the MJO is showing signs that it will move into phase 7 which the anomaly suggests the outlook is this:

    post-4523-0-72726600-1358241339_thumb.gi

    A stonking Atlantic ridge - compare this to the GFS ensemble mean anomaly chart:

    post-4523-0-44059800-1358241472_thumb.gi

    Unable to get ECM ones but the earlier output suggested better ridging.

    So my thoughts - well I think that the GFS is overplaying the strength of the mid Atlantc ridge some what. Yes we are likely to see some energy cross the Atlantic however this is likely to be followed by pressure rises behind linking up with the retrogressing high and a strong greenland block to develop after.

    So any breakthrough is likely to be either temporary, non existant, or limited to the very south followed by a blocked Atlantic.

    This is then going to allow one mighty cold blast from the NE get jolly close to the UK!!!!!

    I think GFS is supprting your theory. On the 500 Hpa today the (both 12Z and 18Z) western circulation will be, due to the Greenland HP, squeezed and somewhat forced a lower path. What puzzles me is the Skandinavien High: will it stay or will it go: is there any indication from the stratosferic movements?

    Posted Image

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    Posted
  • Location: falkirk, scotland, 16.505m, 54.151ft above sea level
  • Weather Preferences: dry sunny average summers and really cold snowy winters
  • Location: falkirk, scotland, 16.505m, 54.151ft above sea level

    just a quick question that hopefully one of the more knowledgable could give me a reply to.

    this is the first year i have been watching the strat through winter and it is great to see how it plays out and how it affects us down on the ground and its made alot easier with the great posts we get in here from u guys.

    the thing i wanted to know with the warming is do warmings usually go on this long with raised temps over the pole or is it all different with each warming with some lasting longer and some shorter and how would u say this warming is compared to previous warmings.

    thanks in advance to anyone who helps me with this enquiry.

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    Posted
  • Location: Weston-S-Mare North Somerset
  • Weather Preferences: Hot sunny , cold and snowy, thunderstorms
  • Location: Weston-S-Mare North Somerset

    Hi all,

    Is there an update on the long term strat profile & our prospects for later in the month & next.

    Is it all still looking good, with any further warming & dis-placed vortex?

    Bacically hoping it's all still looking good for continuing cold!

    Many thanks in advance.

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

    Quick update Steve. Not much change.

    Firstly, the negative mean zonal winds are set to stay negative throughout the period at 10 hPa - that will be at least until 27th Jan before they even recover to positive - never mind average.

    The trend in the mid strat is for the Canadian vortex to wane due to further warming / wave activity leaving the Siberian vortex segment dominant.

    At T+162 10 hpa

    post-4523-0-19283300-1358412610_thumb.pn

    This translates to a more complex pattern towards the surface. The difficulty reamains in the modelling of the strength and positioning of the Canadian vortex tropospherically. However there is one co0mmon theme in that the Siberian vortex segment moves closer to Scandi - and with it some very cold upper tropospheric air. Will there be a trigger to fire it this way towards the end of the month? It can't be ruled out.

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    Posted
  • Location: Dunoon, Argyll, Scotland
  • Weather Preferences: Sun and Snow
  • Location: Dunoon, Argyll, Scotland

    Temperature did fall slightly a few days ago but are on the rise again,

    Edited by weathermaster
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    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

    Are we seeing/experiencing another spike in warming guys, can't seem to access info. Active earth facing sunspot/s, be interesting to see if we see another spike

    BFTP

    Edited by BLAST FROM THE PAST
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