Saturday night and Sunday look very snowy to me. This could easily become a big event with a bit of luck.

http://www.meteociel.fr/modeles/ukmo2.php?ech=48&carte=2000

Originally Posted by: Ally Pally Snowman 

 fergie on NW

I think the key advice is to treat all signals re occlusion debris and small-scale perturbations as untrustworthy. That's what we are doing now until short lead times. Ditto into next week.    

Originally Posted by: sizzle 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=168

Quite a few runs still keen on a cold flow @ 168

Originally Posted by: Gooner 

Indeed young Marcus..Quite a few of those perturabtions would be delivering a convectove snow fest for the SE, especially coastal parts of Essex, Kent and East Sussex.

Originally Posted by: Gusty 

Luck indeed - completely agree.... Even in straightforward set-ups (which this isn't) snow cannot be forecast with any degree of certainty more than 24 hours out.... even then the intensity/depth of the snowfall is really only a nowcast thing.  For other set-ups even getting snow at all is a nowcast event - frustrating but true.... Take last night for instance, when I went to bed at 11pm, BBC had 4 hours of snow IMBY in the small hours.... In the end, it got shunted east and I was about 10 miles west of the main precipitation band, and apart from a tiny bit of sleet/rain I missed it (and you got it you b****** !) and I woke up to green grass.   The recent NYC snow 'debacle' only goes to prove the point further....  I've been lucky as well as unlucky over the years - it's just the way it goes.

No-one should take these charts too seriously, and they certainly shouldn't pick apart exact locations of front etc... they show potential (good potential maybe), nothing more. 

Originally Posted by: Chiltern Blizzard 

Indeed young Marcus..Quite a few of those perturabtions would be delivering a convectove snow fest for the SE, especially coastal parts of Essex, Kent and East Sussex.

Originally Posted by: Gusty 

Have to say we were very lucky last night to get as much as we did here when just a few miles to the north south and west it was a non event. Still think the weekend will spring a few surprises although dew points look marginal here Sat night.

Originally Posted by: Ally Pally Snowman 

Indeed young Marcus..Quite a few of those perturabtions would be delivering a convectove snow fest for the SE, especially coastal parts of Essex, Kent and East Sussex.

Originally Posted by: Gusty 

fergie on NW

Yes. However, despite currently strong EC and MOGREPS signals for cold to relent by end of next week, this still has to be accepted with due caution, with further trough disruption(s) to E still possible to complicate matters and prolong cold weather. That said, it must be noted that - above caveat aside - 00z EC plumes do point with greater consensus towards a clear departure from cold conditions past Friday. Rising GPH remains strongly indicated as high pressure moves in from W; but prior to that, a messy and probably snowy transition (for some). Cold nights still very likely once ridge established, despite moderation in daytime chill.

Signs thereafter, including in UKMO long range model output, broadly suggest that into mid-Feb we will see a phase when a stronger jet will become displaced to a more northerly position, with stronger zonality (and lower GPH) to N of UK and better chance of stronger ridging and thus more benign weather to the south.

Underpinning it all through medium range remains weak teleconnective drivers: MJO not expected to be influential; no signs of any SSW in near future; weak or very indecisive El Nino.      

Originally Posted by: sizzle 

Are we on the verge of some stella runs this evening? GME 132hr

http://www.meteociel.fr/modeles/gmee_cartes.php?&ech=132&mode=0&map=0&archive=0

Originally Posted by: eastcoaster 

here is the latest from fergie over at NW

I think the problem is folk seeing GFS runs through the day and over-reacting to each and every one, rather than taking a step back and appreciating the overall trend/patterns (as opposed to freaking-out over inter-run nuances way out at lead times of T+72+).

Originally Posted by: sizzle 

here is the latest from fergie over at NW

Some clarity re Mon-Tues. Some people here seem to be over-reacting to how UKMO warnings are currently laid-out, plus perhaps some misinterpretation of modelling.

The current warnings into Tuesday (in particular) show E coastal threat of snow showers, because there's higher confidence that the set-up will inevitably lead to these. Conversely, the warnings do NOT currently include anything else across the UK. This is NOT to be misconstrued as UKMO convinced there is no threat of disruptive weather elsewhere: indeed, far from it. It's merely because we are in a lull period - one of careful reflection, if you like(!) - to gather stock of what may or may not be looming into that period.

The threat of disruptive snow *somewhere*, currently rated as 40%, is evident from the UKMO-GM 06z output for Tuesday, with the development of a secondary feature signalled in a number of models (since yesterday) to feed south across western areas. This development evolves from a northward extension of a baroclinic zone, then being engaged and invigorated by a diffluent zone up aloft set to come out across Greenland and then over Iceland. Whilst cross-model support for the upper air pattern is good up to early Monday, the outcomes then diverge markedly - and these key upper sensitivities are crucial to what happens next. Anyone attempting to be prescriptive or offer detail on what will happen is simply bonkers, or misguided. This forecast headache isn't going to resolve speedily!

One thing that is quite evident, however, is how a continued veering of flow Mon-Tues will ensure the country sits under a reservoir of cold air with little scope for marginality in the sense of what we've had this week.

So, it's way, way too premature to either write-off snow prospects for W Country into Tuesday especially, nor 'big them up'. We are in a period of huge uncertainty.  I think the problem is folk seeing GFS runs through the day and over-reacting to each and every one, rather than taking a step back and appreciating the overall trend/patterns (as opposed to freaking-out over inter-run nuances way out at lead times of T+72+).

Originally Posted by: sizzle 

Excellent post, thanks sizzle. Would love to be a fly on the wall at MO HQ right now.

Originally Posted by: wingman 

At the edge of sanity (144) GFS is cold with -9 uppers into the East. 

Originally Posted by: Whether Idle 

This business never fails to amaze me at times. No sooner do we see a fair consensus for a return to westerlies by next Thurs that we get two operationals and another downward trend in the ENS to suggest otherwise. We now have a more robust NE flow possible with -10 knocking on the door of the SE.
Roller coaster don't describe it!

Originally Posted by: nsrobins