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Model Output Discussion - 14th Jan 12z Onwards


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Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

    Let's not forget snow showers in the north tonight and a little feature running along the south coast looking at the bbc weather tonight the have spoke of sleet and snow that could give a dusting.

    Looks like East Sussex East.

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    I'm fairly certain when Frosty see's this chart:     He's going to be outside doing a lot of this:  

    My last post this morn as I'm fed up with the misery in here already. The UKMO at 144 has the PF straddling the UK & a stalled frontal line delivering snow on it similar to feb 96 - It is more a

    Or perhaps it means instead that some 'apparent' absentees are sitting back and looking at a very much bigger picture than simply building cyber snowmen to get knocked down, re-built, and then knocked

    Posted Images

    Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth

    ECM and GFS T144 quite similar in placing the low over Biscay:

    ECM1-144.GIF?15-0

    gfs-0-144.png?12

    Sits well with ECM ens:

    EDM1-144.GIF?15-0

    Once models start moving these kind of lows south faster, I feel they rarely correct north again. I'd suggest the end result will either be exactly what these models are showing above, or else the low sinking even further south.

     

    For a clue as to what might happen if the low did sink further south, GEFS members 2, 7 and 12 all do exactly that by T144 - what has happened to them by T192?

     

    gens-2-1-192.png

    gens-7-1-192.png

    gens-12-1-192.png

    Chalk and cheese - in many ways - though they all seem to be influenced by a SE flow, so perhaps that is what would happen later on if southerly corrections carry on. It's pretty clear, though, that the interaction between the Atlantic High and the jet will decide the way forward locally - and too early to decide on that one.

     

    A slower sinking of the low is probably the best guarantee of a longer cold spell a la UKMO but that's not where this seems to be going right now.

     

    So possibly will be 3/4 days of snow risk, then another 2/3 days of snow cover (where it is laying) under dry, freezing easterlies, then it's down to interactions between systems off the Canadian coast.

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

    It's quite interesting reading the CPC discussion. They've got more confidence in the pattern for the USA from day 8 to 14 than day 6 to 10!

     

    The sum total is that they expect another much colder plunge , so for the UK much depends on whether that energy splits or just runs over any block.

     

    They do have a long discussion about differences between the GFS/GEFS and ECM, this was of course done earlier and won't include tonights ECM ensembles.

     

    Its a very good discussion and I'd advise newer members to give it a go, it talks about teleconnections and how certain synoptic features correlate with others.

     

    I think looking at that discussion and the ECM mean, much depends on whether that dig of brutal cold into the CONUS is centred towards the middle or eastern half of the USA, the middle would keep those lower heights further north and a more elongated stretched PV set up would still give the UK a chance to maintain colder conditions.

     

    http://www.cpc.ncep.noaa.gov/products/predictions/610day/fxus06.html

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    Posted
  • Location: Coney Hall Village 260ft asl, North West Kent
  • Location: Coney Hall Village 260ft asl, North West Kent

    Just a quick heads up before the 12z runs- Chiono.has opened an Upcoming Cold Spell discussion thread here-

    https://forum.netweather.tv/topic/82292-upcoming-cold-spell-discussion/#entry3120000

     

    so if you want to just generally chew the fat on prospects over the next week or so rather than stick strictly to model discussion please post over there.

    Ok cheers all.

    Bump :)

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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

    Well the GEM was an outlier compared to it's mean by T180: post-14819-0-40994000-1421354744_thumb.p

     

    Thats all three main model's means trending towards getting a 24 hour easterly followed by the high sinking around D8.

     

    As for the extended ECM control, it is becoming as much of a joke as the op sometimes. This morning it was a cold outlier on the Dutch ensembles and now it is a whopping mild outlier. Very disappointing. 

     

    12z: post-14819-0-76646600-1421355298_thumb.p  0z:  post-14819-0-35331500-1421355299_thumb.p

     

    The op is reflective of its mean.

    Edited by i'm dreaming of...
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    Posted
  • Location: Kesgrave, just East of Ipswich
  • Weather Preferences: Cold snowy winters, warm dry summers
  • Location: Kesgrave, just East of Ipswich

    Looking at the ECM clusters at D5 they are showing more confidence than this morning, clusters reduced from 6 to 3, so uncertainty has reduced considerably (sadly). The op is aligned to the control with 31 member support so it looks like up to D5 good confidence especially as it is D6 when the Atlantic ridge busts the trough. Cluster 2 has the LP system more blown up and further west so I am not buying that and cluster 3 looks nuts. So all in all it does look like an eureka moment from the ECM ensembles and a flip to a more progressive collapse of the trough. The mean supports that:

     

    attachicon.gifEDM1-168.gif 

     

    Clusters: http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2015011512!!/

    Wow, if that mean chart is supposed to represent something disappointing then it has failed as far as I am concerned; that looks very nice!

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    Posted
  • Location: st albans
  • Location: st albans

    cpc even give europe a mention on the 6/10 day discussion which is something ive never seen before over many years

    INTERESTINGLY, A NEGATIVE  HEIGHT ANOMALY IN EXCESS OF 200M IS FORECAST OVER WESTERN EUROPE DURING THE  PERIOD. 
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    Posted
  • Location: Tonbridge, Kent
  • Location: Tonbridge, Kent

    Well the GEM was an outlier compared to it's mean by T180: attachicon.gifgens-21-1-180 (1).png

     

    Thats all three main model's means trending towards getting a 24 hour easterly followed by the high sinking around D8.

     

    As for the extended ECM control, it is becoming as much of a joke as the op sometimes. This morning it was a cold outlier on the Dutch ensembles and now it is a whopping mild outlier. Very disappointing. 

     

    12z: attachicon.gifeps_pluim_tt_06260 (4).png  0z:  attachicon.gifeps_pluim_tt_06260 (3).png

     

    The op is reflective of its mean.

    And note the mean is the same as this morning.

    Some real cold easterlies beginning to appear in the ENS as well.

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    Posted
  • Location: Cyprus and North east Swindon. 104 ASL
  • Location: Cyprus and North east Swindon. 104 ASL

    cpc even give europe a mention on the 6/10 day discussion which is something ive never seen before over many years

    INTERESTINGLY, A NEGATIVE

    HEIGHT ANOMALY IN EXCESS OF 200M IS FORECAST OVER WESTERN EUROPE DURING THE

    PERIOD.

    What does that mean in forecast terms?
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    Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

    The ECM for Sunday looks great for IMBY: post-14819-0-79979500-1421356184_thumb.p

     

    Probably all change tomorrow but worth keeping on record as I have not seen that amount forecast for a long time  :D

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    Posted
  • Location: st albans
  • Location: st albans

    What does that mean in forecast terms?

    It means the upper trough over w Europe is notably deep as an anomoly. that's why we are going cold.

    The variation at day 5 on the ECM ens (and day 3 with the little depression into the south) is amazing. I dont think we will have the track and shape of the slider low agreed upon until Sundays 00z runs.

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    Posted
  • Location: Coney Hall Village 260ft asl, North West Kent
  • Location: Coney Hall Village 260ft asl, North West Kent

    The fact that IDO is looking for milder solutions at Day 8 tells its own story. 

     

    Good model runs so far today.

     

    Eyes down for the ECM

    Yes a "unique" take on these too

     

    IDO

    The control for the slider stalls the front in the west, probably the most likely scenario, with the main snow north of the M4 in a narrow band:

     

    post-14819-0-76136500-1421342054_thumb.p

     

    That area could see 24 hours of snow if that verified. Again one of several options going forward.

    Edited by Biggin
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    Posted
  • Location: .
  • Location: .

     

     

    The fact that not even Steve Murr can post the day 10 ECM chart with a positive is a true indictment of just how filth that scenario is.

     

    Actually that final chart on the ECM looks like a potential set up for mid-Atlantic block to me which would be stunning. Watch this space.

     

    Meantime maybe let's enjoy a week of cold?

    ECM 240 -

     

    http://www.meteociel.fr/modeles/ecmwf/runs/2015011512/ECH1-240.GIF?15-

     

    Split energy in the atlantic looks to ensure another cold push from the East @ 264...... 

    Seen it many many times-

     

     

    S

    Just seen this: I'm reading through the thread from 6pm and I agree. Big potential there.

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    Posted
  • Location: Brighton, East Sussex
  • Location: Brighton, East Sussex

    Looking at the ECM clusters at D5 they are showing more confidence than this morning, clusters reduced from 6 to 3, so uncertainty has reduced considerably (sadly). The op is aligned to the control with 31 member support so it looks like up to D5 good confidence especially as it is D6 when the Atlantic ridge busts the trough. Cluster 2 has the LP system more blown up and further west so I am not buying that and cluster 3 looks nuts. So all in all it does look like an eureka moment from the ECM ensembles and a flip to a more progressive collapse of the trough. The mean supports that:

     

    attachicon.gifEDM1-168.gif 

     

    Clusters: http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2015011512!!/

    Respect your opinion IDO and find your posts good for a more balanced perspective as you don't just ramp cold.

    That said, that ECM mean looks great to me for day 7, if we look further out 7 day + ENS suites always seem to flatten out these situations in fact I find ensemble suites generally useless at day 10 range as lower resolution pretty much always flattens any ridges and defaults to a more general UK pattern.

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    Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

    The ECM for Sunday looks great for IMBY: attachicon.gif150115_1200_78.png

     

    Probably all change tomorrow but worth keeping on record as I have not seen that amount forecast for a long time  :D

     

    The 18Z HiRLAM has some interesting disturbances in the flow down the North sea - I rate it for convective precip but still a little early for definitive use as a forecast.

     

    hirlam_grunnkort_msl_t850_rain3h_2015011

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

    Hi nick is it not time for your amber âš  alert?

    I ditched that warning system as I think it jinxed things! lol. There are certain aspects of the outputs that are pretty much very likely to verify however theres still uncertainty with the depth and longevity of any easterly and where any frontal snow band might be in relation to the slider low.

     

    If pushed into a corner many of the older crew who have experienced many similar set ups would go with .....!

     

    For the sake of this thread lets just wait and see! lol

    Edited by nick sussex
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    Posted
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl
  • Weather Preferences: Winter synoptics.Hot summers.
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl

    How can we trust the Operational further than 8-9 days with swings like these?

    pluim_06260_0_00_60.png

     

     

     

    Then this for the 12z

     

    pluim_06260_0_12_60.png

    Edited by winterof79
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    Posted
  • Location: Warwickshire/Oxon/Northants Border
  • Location: Warwickshire/Oxon/Northants Border

    How can we trust the Operational furthe than 8-9 days with swings like these?

    pluim_06260_0_00_60.png

     

     

     

    Then this for the 12z

     

    pluim_06260_0_12_60.png

    Those are not for the UK.

     

    But in the current setup any model output past 36 hours is not cast in stone.

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    Posted
  • Location: .
  • Location: .

    How can we trust the Operational furthe than 8-9 days with swings like these?

     

     

     

     

    Then this for the 12z

     

     

    Hey Jason, sorry I missed your earlier question. I think that snow risk chart was for Tuesday.

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

    A mixed bag of EC clusters.... any pronouncements of a secure and swift return to 'mild' conditions need to be taken with pinch of salt. Meanwhile, nearer-term focus needs to be on the late Sat-Sun high WBPT plume curving atop the low running off down into Biscay. *Could* get interesting on N flank of this feature, but wide spread in PPN envelope (e.g. MOGREPS has this anywhere from N France to S Midlands!!)....

     

    Hi Ian- Seeing as data is a little sparse for WBFL & 850 thickness, how much of the leading edge is snow, so if it did end up in the midlands how far back would still be snow- 50% / about 25-30 miles..?

     

    Looking at the plume of PPN it looks solid enough to give a fair covering- especially over elevated areas..

     

    S

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    Posted
  • Location: Peterborough
  • Weather Preferences: Hot summers /snowy winters
  • Location: Peterborough

    Those are not for the UK.

     

    But in the current setup any model output past 36 hours is not cast in stone.

    But they are good to look out when a possible easterly is involved .

    wind direction etc

    Edited by feno13
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