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Model output discussion 25th Jan - The final third of winter beckons..


Paul

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Posted
  • Location: Croydon. South London. 286 ft asl
  • Weather Preferences: Thunderstorms, snow, Ice days, warm sunny days.
  • Location: Croydon. South London. 286 ft asl
    48 minutes ago, Rocheydub said:

    Very well aware of its origins ad it's meaning. Thanks.

    I'm afraid you'll be sadly disappointed!

    http://www.meteociel.fr/modeles/ukmo2.php

    I'm viewing it on my phone but I think it's a bit different to last night's run, not great but slightly better with more amplification to the NE. 

     

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    Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.

    @Bring Back1962-63 has made some fascinating points as usual about the starting data and early progression of the NWP vs live weather observations. The Euro cold block does indeed appear to be more resilient and the GEFS is starting to reflect this. Looking at central Europe and the Warsaw ensembles, the milder runs are disappearing and being pushed further back. I won't try to predict what this means for UK weather, I'm no expert by any means, but just wanted to share this observation that @Bring Back1962-63 has already explained well and is now being hinted at in some NWP output.

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    Posted
  • Location: Cambridge, UK
  • Weather Preferences: Anything out of the ordinary!
  • Location: Cambridge, UK

    Pretty poor again this morning.
    Rmgfs144sum.gif

    Rainfall total charts for the next week showing a definite W/E split - indicative that fronts aren't going to move completely across the country, rather get slightly stuck out west, or lose intensity as the make their way east. Some high-ish totals, though nothing to set the alarm bells ringing yet.

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    Posted
  • Location: Cambridge, UK
  • Weather Preferences: Anything out of the ordinary!
  • Location: Cambridge, UK

    ECM also goes unsettled...with a 'weather bomb' low winding up.

    990mb and innocuous enough at 144 hours:

    Recm1441.gif

    Within 24 hours it's down to 965mb, with gales in the west:

    Recm1681.gif

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    Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.
    10 minutes ago, bluearmy said:

    When the back end of ECM op fits nicely with the mean anomoly  then it's a pretty decent fi  for plausibility 

     

    Except when it keeps changing the T144 output pretty much every run ;-)

    I'm still not convinced about things from next Tuesday.

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    Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
    16 minutes ago, jvenge said:

    Except when it keeps changing the T144 output pretty much every run ;-)

    I'm still not convinced about things from next Tuesday.

    Indeed, lots of variation and swings from T144, look at the cold pool that now develops over eastern and central Europe on this run compared to the last run, so much variation run to run it is actually quite amusing in a way.

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    Posted
  • Location: st albans
  • Location: st albans
    12 minutes ago, jvenge said:

    Except when it keeps changing the T144 output pretty much every run ;-)

    I'm still not convinced about things from next Tuesday.

    there are subtle changes in the mid term but the fi trend remains the same (and gets closer to verifying now) and the Atlantic trough looks like it will win with sceuro blocking trying its best to fight back but not seeming like it will influence far enough west to make a big difference here. the ebbs and flows of the ops are apparent but the slow march to where the ext ens have told us we are going gets us closer and closer to less settled over nw Europe. 

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    Posted
  • Location: st albans
  • Location: st albans
    1 minute ago, Seasonality said:

    Indeed, lots of variation and swings from T144, look at the cold pool that now develops over eastern and central Europe on this run compared to the last run, so much variation run to run it is actually quite amusing in a way.

    A meso scale feature which will be gone next run or two. cold pools have over e. Europe travelling around the ridge have come and gone on many runs  recently.  They won't get this far unless the Atlantic jet (and vortex movement into Canada) is wrongly modelled by all the output 

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    Posted
  • Location: North Norfolk
  • Location: North Norfolk

    So are we seeing the modelling of a displaced vortex (as a result of stratospheric warming) over eastern Canada which is fuelling the jet and leading to the increase in Atlantic zonality? 

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    Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
    58 minutes ago, bluearmy said:

    A meso scale feature which will be gone next run or two. cold pools have over e. Europe travelling around the ridge have come and gone on many runs  recently.  They won't get this far unless the Atlantic jet (and vortex movement into Canada) is wrongly modelled by all the output 

    Well yes blue, the fact it will be gone/different in one or two runs is sort of the point jvenge and I were making. One or two runs in the past this looked rather different again. Neither of us suggested it would affect the UK.

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    Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
    4 minutes ago, jvenge said:

    GEFS mean temperature. No other way to say it; It's showing mild.

    Screen Shot 2017-01-26 at 10.44.39.png

    Careful, I remember the last time you posted one of those the cold returned to Europe :D

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    Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.
    Just now, Seasonality said:

    Careful, I remember the last time you posted one of those the cold returned to Europe :D

    True, but BA did raise an interesting point. Although a lot of the medium output is changing around, the longer term seems to be delivering a similar result. It's still FI, though, and I just can't bring myself to trust it :-)

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    Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
    12 minutes ago, jvenge said:

    True, but BA did raise an interesting point. Although a lot of the medium output is changing around, the longer term seems to be delivering a similar result. It's still FI, though, and I just can't bring myself to trust it :-)

    He certainly did, was all meant in good fun though... :)

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    Posted
  • Location: Cambridge, UK
  • Weather Preferences: Anything out of the ordinary!
  • Location: Cambridge, UK
    7 minutes ago, Summer Sun said:

    UKMO extended is wet and windy UK wide

    ukm2.2017020200.168.lant.troplant.prp.fcst.gentracker.png

    Indeed - ties in with what the general consensus now, in that the NW will bear the brunt, and the SE will fare better. Rain and wind for all though.

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    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
    2 hours ago, Stephen W said:

    So are we seeing the modelling of a displaced vortex (as a result of stratospheric warming) over eastern Canada which is fuelling the jet and leading to the increase in Atlantic zonality? 

    Depends which part of the stratosphere you look at, higher up at 10 hPa the core of the sPV is over Norway at day 10, whilst lower down at 150 hPa the core of the vortex is over Greenland with a trough in the geopotential height field digging SW into NE Canada - so the lowest part of the strat is broadly reflective of what's going on in the troposphere - with a zonal flow across the Atlantic.

    ecmwf10f240.gifecmwf150f240.gif

    Yes, we are seeing a warming of the stratosphere which is displacing the vortex off the pole, but because the warming/reversal of the zonal winds is above 10 hPa still at day 10, winds remain zonal below all the way down into the troposphere at 50-60N, if anything, the latest EC strat charts from Berlin suggest downwelling of the zonal reversal less likely at day 10.

    The much anticipated SSW to change the pattern  is still not happening from EC projections, so maybe close but no cigar, but we may see further attempt in February. The problem is the strat warming and wind reversal in the top layer of the  strat is working against a background of strong westerly QBO and with low AAM and weakening MJO propagation, for now. There are signs that further wave 1 warming impacts on the strat combining with MJO emerging out of COD into more favourable phases for wave amplification around 2nd week of Feb could have another go at bringing a SSW and also changing the trop pattern in the meantime while we await the effects of the warming on the strat working down to the troposphere.

    But, for now, although the Atlantic trough struggles to get east past the UK in the means out to day 15 on the 00z EPS z500, the UK will be too far west to benefit from the block to the  east, so we've got an increasingly unsettled period of weather to endure from the weekend, with no time limit on it for now, some deep lows look like arriving from mid week too. But the way I see, it's been very dry this winter so far, particularly this month, so perhaps we need some rain to top up the water reserves before winter perhaps returns later in February.

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    Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.
    11 hours ago, Jason M said:

    Nope not kidding, its a Bartlett set up. Persistent band of high pressure to our SE. Its not exactly the same as the 1988 version of course and as said above it might not happen like that, but IMHO the 18z is a Bartlett set up (much like most of Dec tbh).

    A Bartlett, you say .... "not exactly the same as 1988 version" ..... damned right - nothing at all like the '88 orange monster.

    I've never seen a 'blue Bartlett' before ... maybe it's been affected by all the European cold. :cold:

    What you are seeing is mostly returning polar maritime air - a Bartlett has very warm upper air, centred over France, and feeds a constant train of tropical maritime air into the UK.

    Compare the 18Z animation to a typical Bartlett type chart.

    tempresult_fww2.gif    archives-1998-2-12-0-0.png

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    Posted
  • Location: Truro
  • Weather Preferences: winter and summer
  • Location: Truro

    Still wondering weather we could see pressure rise more to our north/east.

    with the low pressure system diving south and east all the time along with the jet stream I think this could be where we start to see somthing develop.

    again I don't think anything is set in stone right now and with SSW going on i really don't think we can rule anything out.

    change is a foot!  One way or another .

    IMG_0968.PNG

    IMG_0969.PNG

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    Posted
  • Location: Santry, Dublin, Ireland. 50 metres ASL.
  • Location: Santry, Dublin, Ireland. 50 metres ASL.

    Yep, the jetstream won't be the cause of us not getting a MLB/HLB this winter, that's for sure! That chart above is very conducive to one developing... Alas!

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    Posted
  • Location: Truro
  • Weather Preferences: winter and summer
  • Location: Truro

    Also not seeing quite so much of the PV over Greenland is a great sign. Small wedges can open up a greater  hole.

    so hopefully we see more energy diving further south on every run and hope that night pressure over Russia gets sucked in more to our N/E

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    Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.

    Cold advanced a little colder west on the 06z. Comparison with 0z for easy reference. Re the time frame, the move starts sooner than that, but I don't really want to be posting too many images.

    gfs_t2m_anom_eur_33 (1).png

    gfs_t2m_anom_eur_34 (1).png

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    Posted
  • Location: Wirral, Merseyside
  • Weather Preferences: Snow, Sunny crisp frosty days & Thunderstorms
  • Location: Wirral, Merseyside
    8 minutes ago, Argyle1980 said:

    Still wondering weather we could see pressure rise more to our north/east.

    with the low pressure system diving south and east all the time along with the jet stream I think this could be where we start to see somthing develop.

    again I don't think anything is set in stone right now and with SSW going on i really don't think we can rule anything out.

    change is a foot!  One way or another .

    IMG_0968.PNG

    IMG_0969.PNG

    I agree. The Atlantic still struggling to get past the UK, pressure rising slightly to the north on this run, yes it's 240 but that would be a nice trend.

    gfsnh-0-240.png

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    Posted
  • Location: Orpington Kent
  • Weather Preferences: Snow freezing rain heat waves
  • Location: Orpington Kent

    Turning  unsettled  with some  welcome rain but how long will this unsettled spell last a sign of high pressure  building to the north east again..

    IMG_0285.PNG

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