View Single Post
  #28   Report Post  
Old December 18th 08, 11:06 PM posted to uk.sci.weather
Dave Cornwell Dave Cornwell is offline
external usenet poster
 
First recorded activity by Weather-Banter: Jan 2007
Posts: 1,720
Default Christmas week trends (update 18/12/08)


"Will Hand" wrote in message
...

"Dave Cornwell" wrote in
message ...

"Will Hand" wrote in message
...
No real surprises today.
Still anticyclonic and turning colder.
Ensembles reflect variability nicely.
Here are my revised probabilities for Christmas Day from subtle trends:

Anticyclonic east or southeasterly, becoming colder during the day, but
dry
with some sunshine, although a raw wind along south coast - 70%
Anticyclone centred right over UK with fog and frost - 20%
Strong cold easterly in south with drizzle, snow grains or light snow,
otherwise dry and cold - 10%

Will
--

At the moment my rose tinted glasses aren't quite strong enough to be
that hopeful. 12z GFS mean 850 hPa's are down 3deg on yesterday and most
of the ensemble members (Boxing Day) are tightly clustered around or just
above the mean, which is in fact dragged lower by approx 4 much more
scattered lower runs. Nevertheless it shouldn't be that horrible mild
damp Christmas stuff and it's still way to far away to be sure, as your
probabilities indicate.
Dave



Dave, 850 hPa temperatures are not really indicative of surface temps. in
this situation of high pressure and a likely steep inversion. Also cold
easterlies tend to undercut like a wedge. I was also careful to say a cold
easterly rather than a "very cold" easterly. I put a lot of thought into
this you know!

Cheers,

Will
----------------

Yes , I realise all that Will. Just noting the differences to the previous
day and being my usual pessimistic self ;-)
Dave