Here is a summary of the NWP output for 12z on Wednesday.
Issued 0551z, 27th October 2007

The latter half of the working week will see a north/south split, with high
pressure bringing largely dry weather to southern parts of the UK, while
northern areas are at greater risk of rain moving in from the Atlantic. Into
the weekend high pressure will move NE'wards across the UK, bringing dry
weather for most,

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
SW'lies cover the UK, with complex low pressure to the north and west and a
high over France. Tomorrow the SW'lies strengthen as a trough moves in from
the west. Monday sees westerlies as the trough moves away to the east and on
Tuesday the westerlies become a little lighter as a ridge moves closer from
the west.

T+120 synopsis
http://85.214.49.20/pics/Rtavn12015.png /
http://85.214.49.20/pics/Rtavn1201.png
http://85.214.49.20/pics/Rjma1201.gif /
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 strong jet to the north, with the UK under a
large ridge. At the 500hPa level there's also a large ridge over the UK,
with a tight westerly gradient to the immediate north. MetO also has an
upper ridge over the UK, as is the case with ECM, GEM and NGP.
At the surface GFS brings SW'lies and WSW'lies, with high pressure over
France. ECM also shows a high to the south, with SW'lies as a result. NGP
brings SSW'lies and a high over northern France and GEM is very similar.

Evolution to T+168
ECM shows westerlies and SW'lies on day 6 with high pressure persisting to
the south. On day 7 high pressure remains to the south, but another high
builds to the WNW. Westerlies cover the UK as a result.
A high covers England and Wales on day 6, while Scotland and Northren
Ireland lie under southerlies. On day 7 the high extends to Northern Ireland
as well, with Scotland seeing westerlies.

Looking further afield
The ECM shows a high over Scotland on day 8, with NE'lies elsewhere. The
high drifts eastwards on day 9, with SE'lies for Scotland and Northern
Ireland. Elsewhere winds are ENE'lies. The high builds on day 10, with
SE'lies and easterlies across the UK.
GFS on day 8 brings a high over Scotland and northern England, with ENE'lies
across the rest of England. Elsewhere winds are SE'lies. Day 9 sees SE'lies
and southerlies as the high builds over Scandinavia. The high builds in situ
on day 10, with a col and light winds over the UK.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles for London show a cool blip on Monday, followed by mild and
dry weather for the rest of the working week.