Risk of widespread snow on Sunday
On Friday, February 8, 2013 9:40:40 AM UTC, Scott W wrote:
On Feb 8, 9:26*am, "Eskimo Will" wrote:
"Scott W" wrote in message
....
On Feb 8, 8:52 am, "Eskimo Will" wrote:
"Adam Lea" wrote in message
...
On 07/02/13 08:49, Eskimo Will wrote:
I shall be pin-pointing Sunday in my weekly forecast as a potential day
for disruptive snow. Not just on hills but eventually for low-lying
populated areas too.
A major trough disruption is about to take place, all models are keen
on
it. Initially the air will be too warm for lowland snow and there will
be quite a bit of rain. But as the disruption gets underway, winds will
fall light as the trough stretches and precip. will persist. The warmer
air will occlude out and in the light winds latent heat processes with
melting snowflakes will hasten a cooling process and the wet-bulb
freezing level will come down rapidly. This process most likely Sunday
afternoon and evening. Sunset also obviously aiding the temperature
fall. So a period of moderate or heavy snow in bands then slowly
petering out. One to watch and one where tangerine warnings will be
issued in due course by UKMO. Who gets what and when will have to wait
of course.
Will
Do you think there will be much chance of any lying snow in the Surrey
hills?
Possibly on Monday morning.
Will
--
Risk on Weather Online charts this morning restrict it to a temporary
covering, gone by Monday rush-hour. So from 18cm by Wednesday morning
to bugger all in 24hrs. Another damp squib - at least in low-lying
south-east?
===================
It's a tricky one. At present if you take the models at face value the
disruption is slower and consequently low centre is further north on Sunday
with colder air tucking further south on Monday. Warm air is forecast to be
present around the low with wet-bulb freezing levels circa 800-1000 metres
asl. That means rain at all levels in England apart from northern mountains
on Sunday this turning to snow during Monday as low sinks south but petering
out as it does so. I fully expect the warnings to be revised and more
focused towards the Midlands northwards, if the MetO accept the 00Z runs and
their internal 06Z run does similar. We love the rain in the south don't we!
:-) It can all change again, disruptions are tricky processes for models. I
did say "Who gets what and when will have to wait" and we may have to wait
till Saturday to be sure. MetO site specific run still brings snow into
Dartmoor Sunday evening with heavy snow at Haytor by midnight. About 3-6
hours slower than I suggested yesterday, happy with that!
Will
--http://www.lyneside.demon.co.uk/Haytor/automatic/Current_Vantage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
The only thing that can be predicted with some kind of certainty at
the moment is a blizzard of toys flying out of prams over on TWO
sometime in next 72 hours
*))
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