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


Paul

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Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

Ukmo looks fine and chilly at t144 same as gfs ,ecm not quite as good ,but nothing is in the reliable time frame for an easterly which is at the 72 hours marks ,until you see it at that time frame ,then think it won't verify !

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Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.
5 minutes ago, Seasonality said:

Me too, constant chopping and changing run to run. 

Maybe it's the curse of not seeing the members, but ECM has been very inconsistent these last few days.

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Posted
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
  • Weather Preferences: Northeasterly Blizzard and sub zero temperatures.
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
25 minutes ago, carinthian said:

rThis is the best chart of the day from UKMO and now with-in the reliable time span at 144t. Good to see the Scandinavian high holding its position and looks to be moving slightly poleward (NW), which must be a good thing for the longer term outlook. Also seems to be some colder air aloft moving towards SE Britain associated withf the lower heights over mainland Euroland which should give some snow in this location. Best chart of the season from UKMO this morning FOR YOU GUYS.

c

 C

UKMOPEU00_144_1.png

Just to back up the UKMO chart above some impressive cold uppers into Eastern Britain by 144t. Some of the deeper cloud in the upper flow should produce snow, mostly light falls in the favoured region aligning to the Low countries to affect parts of SE England, mainly Kent, Sussex and Essex, I would think at this stage.

 C

GFSOPUK00_144_2.png

Edited by carinthian
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Posted
  • Location: Sevenoaks, Kent
  • Location: Sevenoaks, Kent

UKMO has been the best performing model this winter, IMO, although the ECM and GFS solutions can't be discounted. The 18oz has also out performed the other GFS solutions. Still much too play for re cold, even if this mornings runs are a step backwards. 

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Posted
  • Location: Scouthead Oldham 295mASL
  • Location: Scouthead Oldham 295mASL

Ecm is being a real pain now.

Still, lots to be resolved with energy distribution very complex.I wouldnt be at all suprised to see more chopping and changing over the next 24 hours.

For my part i just feel the least best model for cold nearly always proves correct.

Is it bad luck? Or is there bona fide reasons why we just dont seem able to get a decent cold spell anymore..

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Posted
  • Location: oldham
  • Location: oldham
26 minutes ago, CreweCold said:

The influence of the Azores HP and its effects of encouraging just too much jet N is a trend that's been there for 36 hours or so. You can look back in the thread because it was pointed out a fair few pages back. 

The fact that this pivotal part of the evolution happens at just 3 days out should set at least some alarm bells ringing. Even in the worst case scenario, it doesn't mean we're precluded another push from the E/NE later on as I don't think this will be the only spell of interest in the coming weeks (and with that the 9 &10 day ECM look questionable to me in terms of going forward).

The Azores high is not the driver here it's the Scandinavian high that's the driver. It that high sets up to far east it makes it more difficult for the UK to get cold air. If it sits up further West then it matters not what the Azores high in this case a temporary surface Ridge being pushed north ahead of disrupting energy against the real blog k to the east.

 

Edited by frosty ground
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Posted
  • Location: Wythall, Worcestershire, 150m asl
  • Weather Preferences: Continental climate, snow winter, sunny summers
  • Location: Wythall, Worcestershire, 150m asl
4 minutes ago, northwestsnow said:

Ecm is being a real pain now.

Still, lots to be resolved with energy distribution very complex.I wouldnt be at all suprised to see more chopping and changing over the next 24 hours.

For my part i just feel the least best model for cold nearly always proves correct.

Is it bad luck? Or is there bona fide reasons why we just dont seem able to get a decent cold spell anymore..

The transition from 192-216 hours looks a bit too progressive to me from the ECM this morning and I don't buy it. Think it will be on the mild side of the ensembles for sure.

As long as the 'misery' UKMO model is rock solid I'm retaining reasonable confidence for next week of something decent from the east.

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Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire

Ecm is a huge concern. I will be brief and to the point on this one as I have a job to go to lol. My prediction for the day is as follows. The GFS 06z will still show the Easterly eye candy but the 12z runs will revert to the ecm way of thinking. Seen this so many times over the years. Crewe beat me to it earlier with his comments about the azores ridge spoiler. It is this that looks like scuppering the Easterly as it hinders trough disruption into France.  The azores high is a real pain in the gonads. 

Edited by blizzard81
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Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
13 minutes ago, frosty ground said:

The Azores high is not the driver he it's the Scandinavian high that's the driver. It that high sets up to far east it makes it more difficult for the UK to get cold air. If it sits up further West then it matters not what the Azores high in this case a temporary surface Ridge being pushed north ahead of disrupting energy against the real blog k to the east.

 

I disagree mate. It matters not one jot if that high sets up too far east IF you get the correct profile to the west of the HP cell. To embellish this point, if you get a perfect split flow in jet energy, you will see low pressure disrupt favourably along the southern arm, whilst the northern arm recurves at the other terminus of the HP cell (also known as a retrograde jet or 'reverse zonal'). Both of these arms of the jet in tandem work to pull the HP back west. 

If the profile to the west of the HP is not correct/favourable you get changes in the distribution of jet energy which then has a knock on effect to the shape and rigour of the HP. What started off as a well rounded block becomes uneven and unbalanced, often aligning poorly for us and thwarting CAA into the UK. You have more wriggle room further E in Europe but in our location we often lie on the periphery as it is.

It's why a spectacular E'ly is so rare to get in the UK...because they require the perfect split in jet energy. Otherwise you end up with these one or two day wonders that we see slightly more frequently.

Edited by CreweCold
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Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire
9 minutes ago, northwestsnow said:

Ecm is being a real pain now.

Still, lots to be resolved with energy distribution very complex.I wouldnt be at all suprised to see more chopping and changing over the next 24 hours.

For my part i just feel the least best model for cold nearly always proves correct.

Is it bad luck? Or is there bona fide reasons why we just dont seem able to get a decent cold spell anymore..

With regards to your last paragraph,  I feel there is so much we don't know about -  yet! 

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Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

If one model backs away from cold ,you just know it will be the correct solution ,the Azores high has been a pain all season 

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Posted
  • Location: Scouthead Oldham 295mASL
  • Location: Scouthead Oldham 295mASL

Steves online but quiet.I love his enthusiasm when cold is on the menu but he hasnt commented which is a bit of a worry.

Anyway, we await the EC ens, really hoping Ec Det is a mild member!

Edited by northwestsnow
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Posted
  • Location: Tamworth, Staffordshire (83m ASL)
  • Weather Preferences: Heat, Thunderstorms, Snow
  • Location: Tamworth, Staffordshire (83m ASL)

The ECM is not a concern for me. Contrary to its reputation it's actually been very unreliable. Like the most overrated football player. Actually  we shouldn't give it so much weight after 120h. As others have said as long as UKMO is interested then we can feel a bit more confident.

Hope to see upgrades from now on as we are approaching the most important time where things can go wrong, in this case as blue army said 3 days out

 

Edited by Paceyboy
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Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire
12 minutes ago, frosty ground said:

The Azores high is not the driver here it's the Scandinavian high that's the driver. It that high sets up to far east it makes it more difficult for the UK to get cold air. If it sits up further West then it matters not what the Azores high in this case a temporary surface Ridge being pushed north ahead of disrupting energy against the real blog k to the east.

 

Couldn't agree more the scandi high is an absolute beast and for me there's no way I buy that the northern arm will get over the top of it.  It's stretching right up into the pole and will take a mighty jet streak to sink it especially given the mjo  amplification through 8/1 I just don't see it myself but each to there own

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Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth

output and people don't control whether it will snow or not. Both are merely making an informed guess. The weather does what it likes. I said yesterday that it is not clear and the same is today. Past t120 is fi for a reason. Go back say a week and look what was being predicted for today and you will see the difference between the prediction and reality. 

Much to be resolved and fun to watch the next few weeks unfold. 

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Posted
  • Location: Scouthead Oldham 295mASL
  • Location: Scouthead Oldham 295mASL
8 minutes ago, CreweCold said:

I disagree mate. It matters not one jot if that high sets up too far east IF you get the correct profile to the west of the HP cell. To embellish this point, if you get a perfect split flow in jet energy, you will see low pressure disrupt favourably along the southern arm, whilst the northern arm recurves at the other terminus of the HP cell (also known as a retrograde jet or 'reverse zonal'). Both of these arms of the jet in tandem work to pull the HP back west. 

If the profile to the west of the HP is not correct/favourable you get changes in the distribution of jet energy which then has a knock on effect to the shape and rigour of the HP. What started off as a well rounded block becomes uneven and unbalanced, often aligning poorly for us and thwarting CAA into the UK.

Totally agree with you crewe.

I mentioned that azores high a couple of days ago.

Its funny really you can guarantee it will be AWOL come summer..:nonono:

Edited by northwestsnow
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Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire
9 minutes ago, CreweCold said:

I disagree mate. It matters not one jot if that high sets up too far east IF you get the correct profile to the west of the HP cell. To embellish this point, if you get a perfect split flow in jet energy, you will see low pressure disrupt favourably along the southern arm, whilst the northern arm recurves at the other terminus of the HP cell (also known as a retrograde jet or 'reverse zonal'). Both of these arms of the jet in tandem work to pull the HP back west. 

If the profile to the west of the HP is not correct/favourable you get changes in the distribution of jet energy which then has a knock on effect to the shape and rigour of the HP. What started off as a well rounded block becomes uneven and unbalanced, often aligning poorly for us and thwarting CAA into the UK. You have more wriggle room further E in Europe but in our location we often lie on the periphery as it is.

It's why a spectacular E'ly is so rare to get in the UK...because they require the perfect split in jet energy. Otherwise you end up with these one or two day wonders that we see slightly more frequently.

The only thing I see the Azores doing to be honest is sinking back to the Azores, it may interfere briefly but you have a deep trough to the west of Britain, low pressure in the med, and high pressure to our northeast, there's only way that energy is going to disrupt and that's southeast and send the Azores packing imo but it's fun watching the roller coaster 

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Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

MJO and Strat favour Northern blocking as time goes on, so seeing the PV gather pace further into FI doesn't make much sense. Surely if MJO and strat warming are happening there is a bigger chance FI would get better , not worse. On that note I imagine charts will start showing more potential over the next few days, not a rebuild of PV and a westerly quadrant flow.

This doesn't suggest a return of PV - how accurate is this!!

IMG_4148.PNG

Edited by Ali1977
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Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK
13 minutes ago, Ali1977 said:

MJO and Strat favour Northern blocking as time goes on, so seeing the PV gather pace further into FI doesn't make much sense. Surely if MJO and strat warming are happening there is a bigger chance FI would get better , not worse. On that note I imagine charts will start showing more potential over the next few days, not a rebuild of PV and a westerly quadrant flow.

This doesn't suggest a return of PV - how accurate is this!!

IMG_4148.PNG

Coupled with this though:

nao.sprd2.gif

NAO is also positive. Could be a case of a good AO and bad NAO conspiring against us if things end up in the wrong place. On a knife edge (as it often is for the UK).

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Posted
  • Location: North Norfolk
  • Location: North Norfolk

I'm no expert but in the the start thread, I've read that the ECMWF was predicting a fairly swift recovery of the strat polar vortex. Isn't this what it shows this morning with a stronger northern arm of the jet present in the latter stages of the run?

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

The backtrack begins today I'm afraid I love heavy snow but I do feel ecm could be correct some cold air coming in from east but mainly dry maybe some snow showers in south east England but mainly cold and very dry I hope I'm completely wrong.

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Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

Northern blocking has not been favourable for the UK this winter and ECM looks like continuing that theme.  A not so good start today after an excellent day yesterday.  But they are very only excellent if they are right?  I feel that ECM is on to something here longer term.  However, we should get some cold coming but a HLB lock down......I don't think so unfortunately.  Beware the signs some have warned of. 

 

BFTP 

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