Here is a summary of the NWP output for noon on Wednesday.
Issued 0521, 21st November 2009.

There are signs of a change today. Late next week a low will move slowly
eastwards to the north of the UK, bringing wind and rain across the UK in
association with its fronts. As the cold front clears the UK on Thursday
much colder air than of late will affect the UK, with temperatures returning
to near normal values.

Analysis and evolution to T+120 via GFS
A weak ridge covers the UK, bringing southerlies and SSE'lies for most.
Tomorrow a trough moves eastwards and SSW'lies cover the UK as a result. A
secondary low lies to the east of Scotland on Monday, with strong to gale
force WSW'lies over the UK. A SW'ly flow covers the UK on Tuesday as the
next low approaches from the west.

T+120 synopsis
http://91.121.93.17/pics/Rtavn12014.png /
http://91.121.93.17/pics/Rtavn1201.png
http://91.121.93.17/pics/Rukm1201.gif
http://91.121.93.17/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a moderate westerly flow to the south of the UK,
with a trough over the UK. The 500hPa chart shows a low to the north and
SW'lies aloft, while ECM is more progressive and has the upper low to the NE
instead with upper westerlies for the UK. MetO is similar to ECM, with a low
to the NE, as is the case with GEM and JMA.
At the surface, GFS brings SW'lies for all with a trough to the west. ECM
has a trough over eastern England with strong to gale WSW'lies, while MetO
brings strong SW'lies ahead of a trough to the west. GEM and JMA show a
trough moving eastwards over the UK and SW'lies as a result.

Evolution to T+168
ECM shows a weakening trough over the UK on day 6, with westerlies. On day 7
pressure builds to the west, leading to light NW'lies for the UK.
GFS brings a trough over eastern areas of the UK on day 6 and this leads to
SW'lies for England and Wales with NW'lies elsewhere. On day 7 a weak trough
covers the UK with light winds as a result.

Looking further afield
ECM shows southerlies on day 8 ahead of a trough to the west. On day 9 low
pressure deepens to the west and a trough lies to the south, leading to
ESE'lies. Easterlies and ENE'lies cover the UK on day 10 as low pressure
fills to the south.
Days 8 to 10 with GFS show low pressure moving NE'wards. On day 8 low
pressure covers England and Wales, with NNE'lies for much of the UK.
Northerlies cover the UK on day 9 as the low transfers eastwards and on day
10 winds become NW'lies as the low moves away to the NE.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The ensembles continue to show a much colder feel to things later next week
as temperatures return to normal values.