Jump to content
Cold?
Local
Radar
Snow?

Model output discussion 8th Feb - Cold for now, but then what?


Paul

Recommended Posts

Posted
  • Location: manchester
  • Weather Preferences: Summer & Winter
  • Location: manchester

    A little step back in the models this evening with any cold being confined to Scotland and along the North East coast. Elsewhere is likely to be seeing sleet showers rather than snow.

    Link to post
    Share on other sites
    Spotted a post you think may be an issue? Please help the team by reporting it.
    • Replies 1.6k
    • Created
    • Last Reply

    Top Posters In This Topic

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

    This is exactly the conclusion I formed some time ago. There's no doubt that they have an effect but the correlations between all these measures or at least current understanding of them seems to be limited. I very much admire Tamara et al who are willing to share there knowledge as our understanding of the interplays between them develops. They are often the target of some posters when things don't go to plan but I think we need to accept that our understanding and hence usefulness of these measures In terms of forecasting rather than hind-casting will improve over time.  pioneering is how I see this area right now and I have great respect to those who are willing to share their musings publicly. 

    Yes and one has to say that even though the mother of all cold pools has not hit the UK, a Strong Scandi high has developed and a cold pool is due to hit this weekend so synoptically not far from the mark. And I would not rule out a Greenland block yet. Whether it is strong enough to send a northerly to the UK remains to be seen but yet again synoptically @Tamara can herald this a success for the closeness of the suggested pattern. I don't ever remember her touting a strong Atlantic and we have certainly not seen that. In meridional flows there is always an element of polar temps dropping south but in order for this to happen there is an equal and opposite element of transfer of warm temp anomalies transported north. And for a small country such as the UK we can always miss one and get the other or in this case get both.

     

    And isn't the output a tease with the block retrogressing over Iceland and then retreating back to Europe?

    Link to post
    Share on other sites
    Posted
  • Location: Sible Hedingham, North Essex
  • Location: Sible Hedingham, North Essex
    1 minute ago, 40*C said:

    A little step back in the models this evening with any cold being confined to Scotland and along the North East coast. Elsewhere is likely to be seeing sleet showers rather than snow.

    What model are you looking at?

    Link to post
    Share on other sites
    Posted
  • Location: Longton, Stoke-on-Trent.
  • Location: Longton, Stoke-on-Trent.
    1 minute ago, 40*C said:

    A little step back in the models this evening with any cold being confined to Scotland and along the North East coast. Elsewhere is likely to be seeing sleet showers rather than snow.

    -8 to -10 uppers covering all of the UK. Not confined to Scotland and the North East coast at all.

    gfs-1-60_zoi9.png

    Link to post
    Share on other sites
    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Hmmm, abundant precipitation heading west on Saturday on 18z GFS

    IMG_0079.thumb.PNG.1a8b7cf0d8a15feafa9ca932d521e34d.PNG

    T850s and partial (850-1000mb) thickness look good, need thickness of <129 gpdm

    IMG_0081.thumb.PNG.9d4303fb7ef96516aa74fe324e6df7d2.PNGIMG_0082.thumb.PNG.7c3f23c288b1ee9b21b8fb14b1f6d82d.PNG

    But the dew points look rather marginal for some and mean the difference of rain, sleet or snow.

     

    IMG_0080.thumb.PNG.9ee27f760def7badb89fafc9f6cd9067.PNG

    But as ever with snow forecasting, we won't know whether surface conditions are ok for snow over one particular area or not until much nearer, literally now casting for some, with such marginality. Though suspect east coast would sleet/rain.

    Link to post
    Share on other sites
    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL
    1 minute ago, Nick F said:

    Hmmm, abundant precipitation heading west on Saturday on 18z GFS

    IMG_0079.thumb.PNG.1a8b7cf0d8a15feafa9ca932d521e34d.PNG

    T850s and partial (850-1000mb) thickness look good, need thickness of <128 godmother

    IMG_0081.thumb.PNG.9d4303fb7ef96516aa74fe324e6df7d2.PNGIMG_0082.thumb.PNG.7c3f23c288b1ee9b21b8fb14b1f6d82d.PNG

    But the dew points look rather marginal for some and mean the difference of rain, sleet or snow.

     

    IMG_0080.thumb.PNG.9ee27f760def7badb89fafc9f6cd9067.PNG

    But as ever with snow forecasting, we won't know whether surface conditions are ok for snow over one particular area or not until much nearer, literally now casting for some, with such marginality. Though suspect east coast would sleet/rain.

    This could give a decent covering in places, maybe the BBC/METO will be looking at this quite closely , may only be a covering but tricky driving if it freezes!!

    Link to post
    Share on other sites
    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL

    Promising looking pub run!! 

    IMG_4235.PNG

    Link to post
    Share on other sites
    Posted
  • Location: manchester
  • Weather Preferences: Summer & Winter
  • Location: manchester
    10 minutes ago, Djdazzle said:

    What model are you looking at?

    this is for saturday

    saturday.gif

    Link to post
    Share on other sites
    Posted
  • Location: NR LOURDES SW FRANCE
  • Location: NR LOURDES SW FRANCE

     

    1 minute ago, Nick F said:

    Problem is that's a west-based -NAO look as has been advertised by recent ops and ensemble means in the 6-10 range, and we are the wrong side of the -NAO trough. The progression from there in the extended EPS mean is to merge the -NOA mean trough with the trough dropping down over Scandi - just hope that's the wrong signal, because that would indicate a return to zonality!

    In a word yuk! lol Well there does seem to be a lot of chopping and changing with the ops, the ECM 00hrs had the main block over Canada and tonights developed that further east towards Greenland.

    Not sure if you read GP's post suggesting the MJO might be further east than the WH index. In my determination to find yet more research to see why we would see such a big difference. About ten research papers later and a headache the news is frustrating depending on which way you look at it. In a nutshell no forecasting method is correct, every MJO event exhibits different properties and needs to be treated in that way. Theres an assumption that the VP200 properly captures the correct MJO signal, the research does not prove this. Sometimes its better and other times not, frustrating really because we've had an issue all winter with the MJO forecasts.

    The obituaries for more cold after this easterly seem to have been based around the VP200 so I'm questioning that, whether we see that favourable NH impact from the MJO is still IMO possible.

    Link to post
    Share on other sites
    Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

    A real wintry flavour to the Gfs 18z for the next 4 days with snow showers, ice and moderate night frosts with a bitter Ely flow..proper winter!:cold:

    18_36_preciptype.png

    18_36_uk2mtmpmin.png

    18_45_uk2mtmp.png

    18_72_preciptype.png

    18_72_uk2mtmpmin.png

    18_93_uk2mtmp.png

    18_93_windvector.png

    18_138_uk2mtmp.png

    Link to post
    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.

    What kind of Atlantic jet stream pattern is this?

    GFSOPEU18_192_22.thumb.png.f492eca81b388288dbba3a2185324784.png

    Answer: one that you may not have seen too often before! (where has the jet gone?)

    No wonder it appears that the pattern is stagnant and time has stopped still.

    Link to post
    Share on other sites
    Posted
  • Location: uxbridge middlesex(south east england)
  • Weather Preferences: blizzard conditions. ice days
  • Location: uxbridge middlesex(south east england)

    Certainly a synoptic of variance/progression. 

    Major advection of warm' digging in Western seaboard. .mjo ramification ?!.

     That's an evolving situ of getting the pulse into correction. 

    An more than ample for some cracking height format to the  NW.

    As regards Friday/Saturday precipitation values accomplishments. ..

    Again threat about these via DP'S ..overheads 24/36 hrs(nowcast)

    gfsnh-0-180.png

    Link to post
    Share on other sites
    Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire

    18z very similar in evolution to the ecm 12z. Must admit I was surprised to see some of the top notch experts on here seemingly throw in the towel on a possible Greenland high bringing winter to the UK in about 10 days. They are not normally so absolute in their medium term conclusions.

     

    Link to post
    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.
    1 minute ago, frosty ground said:

    Is it something that can verify

    I doubt that there are too many times when this has been seen before - but the stagnated Atlantic pattern can certainly verify.

    Link to post
    Share on other sites
    Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

    Interesting to see where GFS 18z is going with this run?

    GFSOPEU18_216_1.png

    GFSOPEU18_216_2.png

    ECM 240hrs is hinting at a possible cold shot into Europe and maybe a drift west. Could this be what METO were hinting at in their extended text forecast today?

    ECMOPNH12_240_1.png

    'There is a small risk of a few sleet or snow showers in southern and eastern parts, although confidence is low.'

    Time will tell of course.:)

    Link to post
    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.

    Sometimes it is easy to second guess where the run will end up, but with this type of Atlantic pattern and with a strong wave 1 trop displacement I am struggling here.

    Link to post
    Share on other sites
    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    h850t850eu.png

    A most curious outcome indeed and quite an adjustment from the previous run. Enough to encourage happier dreams tonight as I leave it there for now. Let's keep shifting the broad scale pattern west tomorrow...please! :whistling::D

    Link to post
    Share on other sites
    Posted
  • Location: King’s Lynn, Norfolk.
  • Weather Preferences: Hot and Thundery, Cold and Snowy
  • Location: King’s Lynn, Norfolk.

    Looking much better than the 12z. Stagnant Atlantic jet and more southerly tracking! Better heights around the Greenland area too with a huge cold pool surging out of Svalbard. This is going to be a tricky one. 

    I was thinking it was a rather foolish statement for BBC staff to hype on as if Spring was about to get underway. Ever heard of the saying 'never remove a thread, till April be dead' or n'eer cast a clout, till May be out'!!! 

    Link to post
    Share on other sites
    Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire
    7 minutes ago, chionomaniac said:

    Sometimes it is easy to second guess where the run will end up, but with this type of Atlantic pattern and with a strong wave 1 trop displacement I am struggling here.

    Oh cmon! You should have guessed we would end up in mild south westerlies at day 11 :)

    Link to post
    Share on other sites
    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
    23 minutes ago, nick sussex said:

     

    In a word yuk! lol Well there does seem to be a lot of chopping and changing with the ops, the ECM 00hrs had the main block over Canada and tonights developed that further east towards Greenland.

    Not sure if you read GP's post suggesting the MJO might be further east than the WH index. In my determination to find yet more research to see why we would see such a big difference. About ten research papers later and a headache the news is frustrating depending on which way you look at it. In a nutshell no forecasting method is correct, every MJO event exhibits different properties and needs to be treated in that way. Theres an assumption that the VP200 properly captures the correct MJO signal, the research does not prove this. Sometimes its better and other times not, frustrating really because we've had an issue all winter with the MJO forecasts.

    The obituaries for more cold after this easterly seem to have been based around the VP200 so I'm questioning that, whether we see that favourable NH impact from the MJO is still IMO possible.

    Yes I did read GP's post suggesting  the RMM plots maybe too slow with the MJO propagation which may make sense why the block is on the move so much and why we are seeing a quick development of a Greenland ridge when the RMM plots would infer this happens too soon.

    Certainly the MJO is no guarantee of getting the block to stay in the right place for long enough, especially if it's progressing east quickly toward the Indian Ocean, much rather we saw the stratosphere having a helping hand with a PV split more likely to bring sustained HLB.

    Still, I remain open-minded for the 2nd half of February, the Atlantiic jet is looking rather weak and wavering from next week, so chance that the deep cold pool vortex dropping down toward Scandi could shift further south than models indicate. Just don't want that PV to the NE to dig too far SW and join with low heights/troughing to west of UK / western Europe.

    Link to post
    Share on other sites
    Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

    Just catching up.

    The difference between the ECM at +240 and GFS 18Z is striking. Personally I have lost interest in trying to predict what may happen for next weekend because this winter has been very odd indeed from a forecasting perspective. Main focus now is the Euro 4 and possible snow.

    I will add though the main cause of all this uncertainty for the medium range is the modelling of the Atlantic trough.

    Link to post
    Share on other sites

    Archived

    This topic is now archived and is closed to further replies.

    Guest
    This topic is now closed to further replies.
    ×
    ×
    • Create New...