"Will Hand" wrote in message news:...

"Dave Cornwell" wrote in message
. uk...

"Will Hand" wrote in message
...
Looks like being on the back edge of next Sunday's cold front (maybe up to
5cms
above 400m asl). Classic meridional extension at T+120 on DT12Z GFS. Snow
showers to follow down to 200m asl on Sunday night into Monday.

Will.
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Looks that way with snow showers for me in couple of days following that.
It's a bit of a long way off though I would have thought, to have much
confidence , especially with the charts changing quite a bit with each run.
In the words of Darren ..................

Dave

But there is a consensus developing. UKMO shows the same upper air evolution.
If
ECMWF comes aboard again then at T+120 confidence must be growing. Also
consistent with last week's jet stream pattern which I discussed and said was
not favourable for a return to zonality. Obviously the detail changes but the
broadscale signal is now much clearer.

Will
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STOP PRESS

12Z ECMWF has come on board with the same evolution. That is now 3 separate
models all identical in terms of a cold plunge. In fact ECMWF goes a step
further with full subsequent anticyclonic disruption leaving a cut-off low over
southern Britain on Monday with cold air entrained raising the possibility of
more widespread sleet and snow on low ground.

OK the detail *will* change in later runs and I expect the cold may become less
intense than currently predicted making it a hill snow event, but fascinating
nevertheless for so early in the cold season.

Will
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"Will Hand" wrote in message
...

STOP PRESS

12Z ECMWF has come on board with the same evolution. That is now 3
separate
models all identical in terms of a cold plunge. In fact ECMWF goes a step
further with full subsequent anticyclonic disruption leaving a cut-off low
over
southern Britain on Monday with cold air entrained raising the possibility
of
more widespread sleet and snow on low ground.

OK the detail *will* change in later runs and I expect the cold may become
less
intense than currently predicted making it a hill snow event, but
fascinating
nevertheless for so early in the cold season.

Will

I don't think the 12Z EC operational run was as cold as the 12Z GFS though
on Sunday/Monday but in saying that there was some support, albeit a tad
limited, in the 12Z ensemble for the colder scenario. Interestingly the 18Z
GFS looks very similar to the midday solution. Early days but if it comes
off it could also get a bit dodgy across the Midlands and the higher ground
north of London, e.g. Luton.

Jon.

"Will Hand" wrote in message
...

OK the detail *will* change in later runs and I expect the cold may become
less
intense than currently predicted making it a hill snow event, but
fascinating
nevertheless for so early in the cold season.

Will

Looks like you'll now have to wait a bit longer, Will. This trough
disruption has been causing the models a lot of problems, the GFS in
particular from what I can tell.

48 hours of 'chasing' frost and coming up :-(

Jon.

"Will Hand" wrote in message
...

OK the detail *will* change in later runs and I expect the cold may become
less
intense than currently predicted making it a hill snow event, but
fascinating
nevertheless for so early in the cold season.

Will

Looks like you'll now have to wait a bit longer, Will. This trough
disruption has been causing the models a lot of problems, the GFS in
particular from what I can tell.

48 hours of 'chasing' frost and fog coming up :-(

Jon.

I dont know about snow on Dartmoor, but looking at the latest visible
satpic, the Pyrennees seem to be completely covered in the white
stuff. I dont think I can remember seeing such a decent snow cover so
early in the season.