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Hunt For Cold: Model Discussion - Heading Into Christmas


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Last one from me for 6 weeks before I leave in the morning for Canada . Our experts we use in resort have told me that todays upper air soundings over the Russian Arctic are showing Easterlies now est

After a health scare I have had the best news ever and been given the all clear. What a year it has been weather wise.Just like to take the opportunity to wish Paul,all The moderating team a

Afternoon so 2 hours on the train should be plenty of time for a post- The last 2 weeks the projected SSW has gradually worked through the models & is now 'imminent' ~ 30hours away is when we

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Posted
  • Location: Hernia Bay
  • Weather Preferences: Heavy Snow
  • Location: Hernia Bay

    I don't know why but I still think it's too early to get a proper handle on what is going to happen. The models do not have a clue since they are all over the shop and that is apparent with each one and it's consecutive runs. We are also still in December..... 

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    Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

    Here's Gavin's latest video: 

    You can see that (as 2001-2 clearly demonstrates) SSWs do not always give us what we want; and, you can also see that Steve Murr's contention, that the GFS's rampaging zonality will almost certainly be kicked into touch, looks spot-on!:santa-emoji:

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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    I've removed a few posts this evening as they drifted too far off topic. Can we please try to stick to discussions around what the models are showing. There is another thread for banter, moans or speculation. Many thanks.

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    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

    Large differences upstream between the ECM and the other models .

    It phases the northern and southern streams of the jet towards the ne USA , developing a stronger shortwave and more amplitude ahead .

    If there’s favourable phasing with the PV lobe at day 7 this might help keep the energy back from spilling too far east over the high .

    Edited by nick sussex
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    Posted
  • Location: Isle of Lewis
  • Weather Preferences: Sun in summer, snow in winter, wind in Autumn and rainbows in the spring!
  • Location: Isle of Lewis

    GFS long way off Fl , zonality cut off and Easterly ensues. 

     

    One to define watch. 

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    Posted
  • Location: Solihull, WestMidlands, 121m asl -20 would be nice :-)
  • Weather Preferences: Cold and Snow -20 would be nice :)
  • Location: Solihull, WestMidlands, 121m asl -20 would be nice :-)

    Some lovely cold pooling showing itself in the ECM at 144h over Central Europe, why can’t the HP over the UK be sitting a little further North ?

    E592FA9A-776E-4100-832A-B81FBC079292.thumb.png.f264c97e4ea40f5e9bd212febab3afea.png

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    Posted
  • Location: Essex Riviera aka Burnham
  • Weather Preferences: 30 Degrees of pure British Celsius
  • Location: Essex Riviera aka Burnham

    216z seems a bit flatter than the 0z (I know we should be comparing like to like) but feel like we're getting nowhere quick with the ops...

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    Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

    Casting the netweather net further out to mid Jan..the GEFS 12z postage stamps look interesting with some snow potential!..in the meantime, the next 7-9 days look dominated by high pressure and then beyond that the uk based anticyclone declines and low pressure becomes more influential...fingers crossed things will become more exciting as we head further into January..I got my prayer mat out!??:cold:

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    850tempuk_378_ps_slp.png

    2m_maxtemp_384_ps_slp.png

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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.
    28 minutes ago, Dancerwithwings said:

    Some lovely cold pooling showing itself in the ECM at 144h over Central Europe, why can’t the HP over the UK be sitting a little further North ?

    E592FA9A-776E-4100-832A-B81FBC079292.thumb.png.f264c97e4ea40f5e9bd212febab3afea.png

    As much as I like seeing cold for my location this ECM run just seems a little implausible to me. Odd looking evolution over Central and Eastern Europe, especially compared to its previous run. 

     

    tempresult_alo2.gif

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    Posted
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Location: Back in Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    the GFS parallel seems to evolve the best solution to cold spilling out across the whole NH..esp at the end big height rises across the pole forcing cold out into Europe and America and the eventual pull of heights into Greenland soon after.

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    Posted
  • Location: Solihull, WestMidlands, 121m asl -20 would be nice :-)
  • Weather Preferences: Cold and Snow -20 would be nice :)
  • Location: Solihull, WestMidlands, 121m asl -20 would be nice :-)
    1 minute ago, Seasonality said:

    As much as I like seeing cold for my location this ECM run just seems a little implausible to me. Odd looking evolution over Central and Eastern Europe, especially compared to its previous run. 

     

    tempresult_alo2.gif

    My personal thoughts are all the models are struggling with the SSW and until they get a grip with the down dwelling, these runs will look odd/implausible.

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    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

    On the face of it a very uninspiring ECM run.

    It is different upstream at day 6 with more amplification ahead of the more developed shortwave in the ne USA.

    It makes several attempts to cut some shortwave energy south to the east and the day 6 to 7 timeframe might develop more interest .

    Look out for the ECM spreads to see if that shows a ne sw orientation between day 6 and 7 running towards Denmark and the Low Countries .

    PS no joy in the spreads , on to plan B ! Start praying ! 

    Edited by nick sussex
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    Posted
  • Location: Walsall, West Midlands
  • Weather Preferences: Winter - cold, summer - not hot
  • Location: Walsall, West Midlands
    43 minutes ago, Seasonality said:

    Can we have some sort of function where your posts get read out in Brian Blessed's voice? 

    That's what caps lock is for...  

     

    Pretty uninspired output from ECM it seems, but the GFS maybe a little more hope for us coldies.  However with the SSW apparently in full swing now we should start to see the models reflect that.  If it's going to happen it should happen soon.

    Edited by SJ NM
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    Posted
  • Location: The Purbeck Microclimate, Dorset.
  • Weather Preferences: Gales, T-storms, Heavy Rain, Heat, Cold - Love it all.
  • Location: The Purbeck Microclimate, Dorset.

    OK - Back to the models.. if you have any complaints, please contact a member of the team rather than airing it in this thread.

    Thank you! ?

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    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    The decaying MJO that ECM/EPS continue to go with is likely holding back the amplification across the N. Atlantic a bit D7+. Having said that - it does look a bit excessively 'messy' to the NW and N of the UK on the ECM 12z - something cleaner probably would have led to more of a split vortex appearance by D10; you can see the Canadian, Siberian and Pacific centres of action (mirroring the stratospheric setup) but they lack clear boundaries.

    Funnily enough, should GFS/GEFS manage to lock onto a downward propagating stratospheric split, then with their more amplified MJO solution, I'd actually consider them to be the better guide for D7+ until ECM & EPS caught up MJO-wise... believe me, it's extremely rare for me to even contemplate that! ?

    Important to take note of the major assumption here; that the MJO will remain active due to a colder upper tropical troposphere related to the processes associated with the SSW.

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    Posted
  • Location: East Ham, London
  • Location: East Ham, London
    1 hour ago, cheeky_monkey said:

    the GFS parallel seems to evolve the best solution to cold spilling out across the whole NH..esp at the end big height rises across the pole forcing cold out into Europe and America and the eventual pull of heights into Greenland soon after.

    This was, as I recall, one of the possibilities from the SSW and something mentioned by Judah Cohen as a possible outcome. If you get a strong anticyclone over the Pole the possibilities for cold at lower latitudes increase considerably because, as you rightly say, the cold gets chased south. 

    One evolution touted last week on a number of GFS OP and Parallel runs was dropping the trough into NW Europe or Scandinavia with a mid Atlantic ridge behind it - the 12Z Parallel ends with a sharp N'ly.

    Other evolutions today have returned to the possibility of the mid-latitude block creeping into southern Scandinavia. - you can see the kick of WAA between T+288 and T+300 over eastern Greenland on the 12Z GFS OP that allows an HP to build over Scandinavia and re-enforce the mid-latitude block. 

    Developments in the stratosphere continue to intrigue and perplex in equal measure and as others have said may constitute to make the model output even less unreliable than usual. We seem to have stepped back from an Atlantic breakdown in the New Year to a continuation of the quiet anticyclonic theme but it's by no means assured and a number of the GEFS keep the signal of a revived stronger jet.

    Oddly enough, as the cold does draw out of the Polar region I could see a brief return of a more active regime before more amplification takes hold. 

    The onset of much colder conditions took two and a half weeks in February from the initial PV split so if the split is due Jan 1 that takes us to Jan 18-19 or thereabouts and as I recall there was plenty of wailing and gnashing of teeth earlier tin the year when some output seemed to suggest the SSW having no real effect in our area. 

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    Posted
  • Location: East Ham, London
  • Location: East Ham, London
    4 minutes ago, Singularity said:

    The decaying MJO that ECM/EPS continue to go with is likely holding back the amplification across the N. Atlantic a bit D7+. Having said that - it does look a bit excessively 'messy' to the NW and N of the UK on the ECM 12z - something cleaner probably would have led to more of a split vortex appearance by D10; you can see the Canadian, Siberian and Pacific centres of action (mirroring the stratospheric setup) but they lack clear boundaries.

    Funnily enough, should GFS/GEFS manage to lock onto a downward propagating stratospheric split, then with their more amplified MJO solution, I'd actually consider them to be the better guide for D7+ until ECM & EPS caught up MJO-wise... believe me, it's extremely rare for me to even contemplate that! ?

    Important to take note of the major assumption here; that the MJO will remain active due to a colder upper tropical troposphere related to the processes associated with the SSW.

    Thanks as always my friend for the cogent comment.

    As I recall, back in March, the MJO was at record-breaking levels of amplitude and we saw the HP move west across the northern hemisphere from Scandinavia to Canada. That did for our initial cold spell and I've never seen anything like that.

    I suppose we can never catch a break of getting a reasonable level of amplification to prevent the west-based negative NAO setting up quickly - that also killed the December 2010 spell.

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    The ECM mean suggests next week will be a very short snap it only just about makes it to -2 on the 850's as a peak low

    graphe_ens3_php.thumb.png.6f94d09d34cb90c07f95a3d8c2d79535.png

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    Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

    Ensemble means from GEFS and GEFS(P) still good for -AO from 11th/12th. The question then is whether events between Canada and the uk allow us to benefit.

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    Message added by Paul

    If you're hunting for cold potential in the model output, this thread is for you. But if you'd like to look more widely at the models, please head over to the general model discussion thread.

    This is a model related thread, so a general, frequent theme of the model output is a given, but it will not be strictly enforced:

    • Some topic drift, humorous responses etc are fine
    • Posts likely to lead the thread off on an entirely off topic tangent are not ok. For example (but not solely limited to): Posts entirely or mainly about Met Office, BBC or media forecasts with little or no model context, and posts solely asking for a weather forecast in a specific location.
    • Posts which start with something like 'I know this is off topic but ...' are not ok.
    • Posts which break the forum guidelines are not ok (eg trolling, troll-hunting, weather guilt tripping, overly defensive/aggressive, abusive, disrespectful to others)
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