Yes, its the curse of data that is too frequent.  JMA is a decent model and may well have a better handle on this than the GFS.  Certainly it should be considered.

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Coldest set of ensembles so far for down here - narrowly pipping yesterday's 12z.

The number of members showing an ice day is remarkable. I wouldn't be at all surprised to see an even colder 12z operational tonight, as this morning's run was one of the mildest 20% or so for the 9th and 10th!

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A good update from the MetO which kind of makes my earlier post of it being dry for the next 7+ days redundant somewhat. 😮

It's a very valid point Doc, one which I think you have mentioned before.

We are dealing with a very rare beast here, i would hazard a guess that we don't know the likely outcome of any output with confidence in general until say 72 hours out. Most current output are variations on a theme, that of a large Scandy block. I think the tipping point is Tuesday/ Wednesday, I've a nagging feeling the AZ HP may get involved and cut off any easterly. All we need now is some luck.

All the main models have some energy sliding south as the jet comes up against the block; at around day 5-6.  If that evolution is being modelled correctly then the Azores high is prevented from rigging NE, at least for a couple of days.  After that you're right but T+168 and more is FI: it is conceivable that a surge of WAA may reinforce the block, although I agree it could work to flatten the pattern as per GFS.

 

 

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W COUNTRY OUTLOOK: Shift to colder conditions (E/SE flow) later next week remains strongly signalled; a low (10%) chance of milder SW flow >

 

 

W COUNTRY CONTD... A minority (20%) of model solutions present a risk of much colder air moving W across UK, bringing heavier snow showers >

 

W COUNTRY Into 10-15d period, thro mid-Feb, continuation of below avg temps looks most likely; low (20%) chance W'ly/zonal weather by then

 

 

From IF in the last hour

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Ironic that as the model outlook turns less cold the MetO issues its coldest and wintriest 5-15 day MRF of the winter!

MetO short range MRF has been excellent this winter so I think they have a handle on the developing cold spell as indicated by Ian F. above.

Expect up grades all round on tonight's models.

Andy

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Indeed ^^^^

So off we go then - The 12z is under starters orders....

In respect to everything available at the moment inc the 06z runs & known bias from models we cannot 'expect' The GFS poor solution to be correct- however based on history & the aforementioned bias / weaknesses of this model I would forecast the 12z + 18z & 00z to move to the more Easterly flow as per the JMA 06z-

GFS is also poor with euro heights between around 114-144 in these scenarios often being around 8 dam to heigh- so all if this Should change & manifest in the next 24-36 hours....

S

GFS is not friendly to the UK - has us under mild SW winds on Monday - just the wrong side of the good stuff.

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GFS waking up!

Now a closed ( finally ) trigger low @84

http://modeles.meteociel.fr/modeles/gfs/runs/2017020412/gfsnh-0-84.png?12 

Atlantic held a couple of hundred miles further west on the 12z GFS at T90!
http://modeles.meteociel.fr/modeles/gfs/runs/2017020412/gfs-2-90.png?12 

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Matt H

A 'watered down' E'ly likely next week now. EC ENS still colder than GFS ENS really & details yet to be determined. But no 1991/1987 repeat!

Dry But Cold Looks Likely

http://www.meteociel.fr/ukmo/runs/2017020412/UW144-21.GIF?04-17 


The GFS has a bit of drizzle here 

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Better from UKMO at 144
http://www.meteociel.fr/ukmo/runs/2017020412/UW144-21.GIF?04-17 

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The 12z GFS, like 6z, shows widespread light snow in 5 days' time. The specifics will change of course, but it's still good to see.

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Good UKMO @ 144

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Looks ok any idea of 850s Gooner?

 

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The ukmo shape @ 120 & 144 looks classic--
Take the date away & you would think it was a 60s chart a day or so before deep snow arrived...

Cue francis wilson...

london thickness 536 ish - uppers about -2 to -4

s

 

Thanks Steve should be cold enough for snow then. Great analysis and running commentary much appreciated by many here.

 

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That's a good MetO run for the south east especially, the MetO clearly saw the way things were going when they updated their MRF at lunchtime.

Haven't looked at GFS, I can't be ars*d because at the moment it's just trash.

Andy

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Should be with a bit of luck , hopefully a decent ECM will follow.

Its not been a bad afternoon really , with IF's thoughts and the Met's updates

 

 

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Even this far out the Atlantic is struggling , yes GFS and yes one run blah ! blah ! blah!

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A bit of a snoozefest overall to be honest. 

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cheers

JMA still banging them in

http://www.meteociel.fr/modeles/jma.php?ech=24&mode=1&nh=1&archive=0