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Model Output Discussion - Staying cold into the new year


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Posted
  • Location: Tunbridge Wells, Kent
  • Location: Tunbridge Wells, Kent

    Nice eye candy on the 18z and good to see the parallel run move towards the op, a bit. Short ensembles are excellent too with no member over -4C from 2nd Jan for London. So a bit of improvement to finish the day, where earlier there have been a couple of wobbles in the medium to long term. 

    I think FI is about 96-120, although there is a high probably it would stay on the cold side beyond that timeframe. The easterly now trending to be the right side of marginal, but that could flip back - would only take a shortwave feature to modify the flow. 

    My worst fear is that this could end up like January 2013, which whilst not an awful month, delivering some snow for many, had many nirvana runs that just evaporated, or were very watered down come the end. 

     

     

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    I’m still concentrating on trends with the NH profile after day 5 and all is still good. Even before the expected cold shot I was always convinced an SSW would occur despite some reservations from a n

    I have a bit of an update from the Central European team of forecasting experts. Their charts currently show a strong alignment to the UKMO at 144t.  Looking a head for period 144t -240 they expect a

    If you’ve got a point for a specific member then I suggest you use the PM function. No need to be snippy tonight, I’ve got gin to drink and I’d prefer to not have to referee playground antics in

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    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    Just now, chionomaniac said:

    Nope. That is wrong. The strong split in 2009 was responsible for the easterly in early feb. It was the lack of subsequent blocking in the right place that hindered any further cold opportunities. But that split delivered and led to one of the first met office red warnings. 

    Ok, thanks for clarifying.  I just hope for a split after the potential displacement coming up.

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    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    3 minutes ago, Stu_London said:

    My worst fear is that this could end up like January 2013, which whilst not an awful month, delivering some snow for many, had many nirvana runs that just evaporated, or were very watered down come the end. 

    After the Januaries we've had since then, I would be more than happy with another January 2013!

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    Posted
  • Location: Chessington, Surrey
  • Weather Preferences: Snow, Hot and Sunny but not opressive
  • Location: Chessington, Surrey

    What an awful easterly on the Navgem 

    1595C772-EFAC-484E-BF5C-B06923DE0412.png

    5B977024-00B8-4BEC-B503-EEE745365F07.png

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    Posted
  • Location: weston-super-mare, UK
  • Location: weston-super-mare, UK
    2 minutes ago, Don said:

    After the Januaries we've had since then, I would be more than happy with another January 2013!

    Seconded. To be fair that winter wasn't bad and even we had snow down here a few times. If we get that, I'd take it. 

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    Posted
  • Location: Home: Chingford, London (NE). Work: London (Central)
  • Location: Home: Chingford, London (NE). Work: London (Central)
    3 minutes ago, Stu_London said:

    Nice eye candy on the 18z and good to see the parallel run move towards the op, a bit. Short ensembles are excellent too with no member over -4C from 2nd Jan for London. So a bit of improvement to finish the day, where earlier there have been a couple of wobbles in the medium to long term. 

    I think FI is about 96-120, although there is a high probably it would stay on the cold side beyond that timeframe. The easterly now trending to be the right side of marginal, but that could flip back - would only take a shortwave feature to modify the flow. 

    My worst fear is that this could end up like January 2013, which whilst not an awful month, delivering some snow for many, had many nirvana runs that just evaporated, or were very watered down come the end. 

     

     

    2013 also delivered quite a bit of snow in February and also a frigid March. It definitely delivered a colder second half to winter. 

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    Posted
  • Location: Hollywood, Worcestershire
  • Weather Preferences: Thunderstorms, Cold & Snowy
  • Location: Hollywood, Worcestershire
    1 minute ago, Mark wheeler said:

    What an awful easterly on the Navgem 

    1595C772-EFAC-484E-BF5C-B06923DE0412.png

    5B977024-00B8-4BEC-B503-EEE745365F07.png

    Blimey, I forgot that model even existed. 😬

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    Posted
  • Location: Tunbridge Wells, Kent
  • Location: Tunbridge Wells, Kent
    3 minutes ago, Don said:

    After the Januaries we've had since then, I would be more than happy with another January 2013!

    If severe winters were ranked on conditions indicated in the model output, rather than what actually happened  - Jan 2013 would be number one ranked.

    There was one ECM suite that had the CET at about -6C - I think one member of this forum even changed his name off the back of it.

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

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

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    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    4 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

     

    7 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

     

    Oh well, it was fun while it lasted....  Things may well fall back in our favour!

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    Posted
  • Location: Horley, near Gatwick
  • Location: Horley, near Gatwick
    8 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

    These are 2m air temps? Average doesn’t creep above 5c until right at the end of the suite? 

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    Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
    9 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

    The thing is, at this point it could just be a first stab at what happens after the SSW...and it could be completely wrong. We just don't know.

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    Posted
  • Location: Maidstone, Kent
  • Weather Preferences: Anything below 0c or above 15c (the sunnier the better!)
  • Location: Maidstone, Kent
    8 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

    ...when it comes to cold a lot more can and does go wrong than right! 

    Models are much more used to the behaviour of Atlantic driven synoptics so when you see them pop up in the runs, you know there's a very well trodden path to it. 

    In the UK if you want mild and wet you have a wide road resurfaced every year. If you want snow you'll have to hack your way through undergrowth!

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    Posted
  • Location: Tunbridge Wells, Kent
  • Location: Tunbridge Wells, Kent
    8 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

    I think its a bit premature to be calling a collapse just yet. With all SSWs that I have witnessed, ensembles go absolutely haywire and there a massive medium to long term swings in temperatures and patterns. Below average (albeit not spectacularly) is locked in for about 96 hours which is probably where FI is now and there is a reasonably high percentage chance of a further 96 beyond that, perhaps trending a little colder in that time.

    No one can guarantee an SSW delivering holy grail outputs and eventualities, but you can pretty much guarantee that they will introduce a pronounced increase in uncertainty, a trend I would expect to continue to grow for a few days yet.

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    Posted
  • Location: Chessington, Surrey
  • Weather Preferences: Snow, Hot and Sunny but not opressive
  • Location: Chessington, Surrey
    23 minutes ago, Eskimo said:

    Blimey, I forgot that model even existed. 😬

    It’s my hobby within a hobby , love the Navgem  it even got it right once in the summer too before the others  . Anyway here is another run we certainly don’t want to see verify, This time the Chinese model   .

     

    54AAF433-32B3-4E75-8416-633F16DA0A1D.png

    Edited by Mark wheeler
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    Posted
  • Location: Near Gouda, Holland 6m Below sea level
  • Weather Preferences: Sun, snow, ice. Very hot or very cold.
  • Location: Near Gouda, Holland 6m Below sea level
    18 minutes ago, feb1991blizzard said:

    EPS going the same way - wheels beginning to fall off, i have seen it all before.

    image.thumb.png.810c5ad6d4af4edc54d01b90e7bd8a3b.png

    I noticed that trend too. The mean on both GEFS and EPS seems to be going up, but at the same time the spread is growing.
    There are some more extreme members, like the GFS 18Z Op and the one on the EPS that drops to -16C at 2m in De Bilt 👇

    Pluim_29dec.png

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    Posted
  • Location: Tunbridge Wells, Kent
  • Location: Tunbridge Wells, Kent
    4 minutes ago, Cold Winter Night said:

    I noticed that trend too. The mean on both GEFS and EPS seems to be going up, but at the same time the spread is growing.
    There are some more extreme members, like the GFS 18Z Op and the one on the EPS that drops to -16C at 2m in De Bilt 👇

    Pluim_29dec.png

    The mean falling slightly in the mid range could be good news for us with winds forecast to be easterly during that period. 

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    Posted
  • Location: Near Gouda, Holland 6m Below sea level
  • Weather Preferences: Sun, snow, ice. Very hot or very cold.
  • Location: Near Gouda, Holland 6m Below sea level
    6 minutes ago, Met4Cast said:

    Just going to quote tweet this because some are throwing in the towel already because of increased ensemble spread in the extended suites. 

    Models are still trying to resolve the block placement, some have it further north which allows less cold air on, some have it perfect which is why we’re also seeing some extreme colder members. 

    Look at the postage stamps, every single member contains some form of blocking. This isn’t your usual “oh the Atlantic is about to burst through the block”. 

    FF2490B7-0CB6-41A2-B542-7F7C7DFB5F52.thumb.png.d94523efe612c05de3ea64bdc0e2511a.png

    By day 10, the ensemble spread is HUGE  

    5BE8EFF3-648A-44E6-A158-D51EF8782663.thumb.png.9c294509d6dc9fbc36a16b1c63c58223.png

    This is expected & shouldn’t come as a surprise to anyone. Things continue to look good or even very good from where i’m sitting. Ensemble charts don’t tell the full story. 

    That makes following the model output so much more interesting when blocking is involved. The models always struggle with the exact placement, size and shape of the block, while the difference for us on the ground is huge.

    Dec 2010 was a Goldilocks situation, everything 'just right', in Feb 2012 it was just right for us in Holland (oh, what a cold spell was that!), but not for you in the UK and the situations where everything was 'just wrong' are countless 😢

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    Posted
  • Location: West London
  • Weather Preferences: Winter : Cold, snow, frost, fog. Summer : Sunny N wind + clear skies
  • Location: West London
    1 hour ago, CreweCold said:

    The thing is, at this point it could just be a first stab at what happens after the SSW...and it could be completely wrong. We just don't know.

    In model watching you need to view dispassionately - with the good and the bad. Many times over the decade I've watched, it's worth holding judgement a day or two, taking the John H approach, and having patience rather than knee jerking to every run. We get downgrades and upgrades that often flip as the models seek the solution but ultimately,  what will be will be. Yet in the reliable timeframes there's chances in most places, more so in the North (which is usually, but not always, the way) and beyond that considering what the strat is doing anyone saying they know is being presumptuous.

    I've really enjoyed @Catacol's musings/ramping and I'm also excited for the same reasons. Historic events do happen to us - who would have thought Dec 2010, Mar 2013 and Feb/Mar 2018 were going to happen? but sometimes you spot the seeds sprouting, other times it's gone by the next morning. We could have a decent spell, an historic spell/event or a squib - I've seen so many naysayers be right and horribly wrong. We seriously don't know but like most here at this time of year we live and breathe for snow and ice because we don't live in Scandinavia or Canada. Even @mushymanrob has been perked up for something out of the ordinary! 

    What I will say is the ens for Berks are surprisingly solid showing a steady cool down until the 6th - next Weds - when the scatter builds - it may tighten up or down or scatter further. Cold periods can wax and wane - or disappear, but 7 days of steady cooling with good agreement is not bad at all and chances may pop up (or not) but we're in the game before January has even started with a great stratospheric roll of the dice about to be thrown. I'll take it! 

    My glass is anything but empty in what hemispherically and model wise is possibly the most interesting I have seen. At least this winter isn't boring 🤣

    t850Berkshire.png

    Edited by Weather Monkey
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    Posted
  • Location: South Croydon
  • Location: South Croydon
    1 hour ago, CreweCold said:

    Looking to me like the strat displacement may shuffle the cards against us. A split would be preferable I think.

    At this moment there are signals for such a warm up in mid Jan. Longer range extended EC and GEFS ensembles going for it. The question is a) will it happen and b) can we keep it temporary if it does.

    In the past a SSW has caused the models to break down for a period.  They just haven't been able to model it at first and it's caused a lot of volatility in the NWP output.  So I don't buy the idea that any of the models knows the outcome right now.  It's been 7 years since our last big favourable outcome and whilst programming and models algorithms have been updated, these are rare events and huge difference from the climatical norm.  I don't think there's enough data for them to diagnose all of the impacts.  So I'd expect a period of uncertainty based on the following factors:

    1. Split vs. displacement

    2. Speed of propagation from strat to trop

    3. Location of the blocks in the mid latitudes

    The impact of these events is relatively new to the modelling process.  It's an area that had a thread tucked way away from prying eyes even in these forums until recently (last few years).

    The understanding has come on leaps and bounds recently.  Very unusual to see one when the trop is already disturbed from its norm.  

     

     

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    Posted
  • Location: Windsor
  • Weather Preferences: Snow and cold
  • Location: Windsor
    18 minutes ago, Trom said:

    In the past a SSW has caused the models to break down for a period.  They just haven't been able to model it at first and it's caused a lot of volatility in the NWP output.  So I don't buy the idea that any of the models knows the outcome right now.  It's been 7 years since our last big favourable outcome and whilst programming and models algorithms have been updated, these are rare events and huge difference from the climatical norm.  I don't think there's enough data for them to diagnose all of the impacts.  So I'd expect a period of uncertainty based on the following factors:

    1. Split vs. displacement

    2. Speed of propagation from strat to trop

    3. Location of the blocks in the mid latitudes

    The impact of these events is relatively new to the modelling process.  It's an area that had a thread tucked way away from prying eyes even in these forums until recently (last few years).

    The understanding has come on leaps and bounds recently.  Very unusual to see one when the trop is already disturbed from its norm.  

     

     

    Who cares if it can't snow in Berkshire!

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    Message added by Paul,

    Please stick to discussing the model output in this thread. For more general chat , please use the winter/cold weather/snow chat, banter, moans and ramps thread

    For local cold/snow and weather related chat, please head over to the Regional Area.

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