Here is a summary of the NWP output for noon (GMT) on Wesnesday.
Issued 0504z, 20th September 2008

The middle of the week will see high pressure to the NE and easterlies 
across much of the UK, with western Scotland in particular seeing the best 
of any sunshine. As the weekend approaches the models diverge, with ECM 
bringing settled weather for most (except the north of Scotland by Friday); 
GFS meanwhile shows easterlies persisting as a low slowly approaches from 
the west.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
High pressure covers England and Wales, with SSW'lies elsewhere. Tomorrow 
southerlies cover much of the UK as the high moves eastwards, followed by 
NE'lies and NNE'lies on Monday as a ridge moves in from the west over 
Scotland and Northern Ireland. There's little change on Tuesday.

T+120 synopsis
http://85.214.49.20/pics/Rtavn12014.png / 
http://85.214.49.20/pics/Rtavn1201.png
http://85.214.49.20/pics/Rukm1201.gif
http://85.214.49.20/pics/Recm1201.gif / 
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a split jet to the west, with the bulk of the 
energy going into the northern branch. At the 500hPa level there's an upper 
high to the NE and a low to the south. MetO has a ridge aloft over the UK, 
while ECM also shows a ridge. GEM has an upper high over Scotland and 
Northern Ireland.
At the surface, GFS shows ENE'lies with a high to the NE. MetO's high lies 
to the east of Shetland, with NNE'lies over much of the UK. Northern 
Scotland is the exception, with SE'lies. ECM is pretty much a carbon copy of 
MetO, while GEM has a high over Scotland and NE'lies elsewhere.

Evolution to T+168
Day 6 with ECM brings a ridge over Scotland and Northern Ireland, with light 
southerlies. England and Wales lie under NE'lies. On day 7 pressure builds 
across all areas except northern Scotland, which lies under moderate 
SW'lies.
On day 6 GFS shows ENE'lies for England and Wales, with a mixture of 
southerlies and SSE'lies elsewhere. High pressure lies over the Baltic and 
on day 7 winds become easterlies for most as the high moves SE'wards.

Looking further afield
On day 8 with ECM a ridge from the west covers the UK. WInds are NE'lies 
from the Midlands southwards, with light NW'lies elsewhere. NW'lies cover 
all areas on day 9 as the high to the west declines. Day 10 sees further 
light NW'lies, with an upper trough slowly extending southwards over the UK.
GFS brings SSE'lies and easterlies on day 8 due to low pressure to the 
south. Day 9 sees a trough over the North Sea and light NW'lies for most. A 
weak ridge moves eastwards on day 10, leading to NW'lies for the eastern 
half of England and SW'lies elsewhere.

Ensemble analysis 
(http://91.121.94.83/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=0&ville=Londres)
The ensembles show a cool weeak ahead, followed by a warmer spell.