Here is a summary of the NWP output for 12z on Monday.
Issued 0543z, 11th October 2007

After a dry start to the week for many, a trough will move eastwards
bringing rain to most on Tuesday into Wednesday. After that high pressure
looks like building back again, probably with the centre ending up to the
east or NE by the weekend.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
A large ridge covers England and Wales, with SW'lies over the rest of the
UK. Tomorrow a ridge moves across Northern Ireland and Scotland, with the
main high to the south. Lighter westerlies and WNW'lies cover the UK,
followed by southerlies for all areas except England on Saturday as the high
moves NE'wards. On Sunday high pressure lies to the east, with a ridge over
England and Wales. A mixture of SSW'lies and southerlies covers the UK.

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 trough to the west of the UK, a ridge to the
east and a weak jetstream heading northwasrds over the UK. At the 500hPa
level there's also a trough to the west, with upper southerlies over the UK.
ECM also shows a trough to the west, while NGP has a trough over the UK. GEM
has a trough to the west as with most of the runs today.
At the surface GFS brings a trough over the Irish Sea. Ahead of the trough
there are southerlies, with SW'lies following. ECM's trough is over Ireland,
with SSW'lies for all, while NGP shows the trough over the North Sea
instead, leading to WNW'lies. SW'lies cover the UK with GEM, due to a low to
the WNW.

Evolution to T+168
ECM shows the trough progressing eastwards on day 6, moving slowly eastwards
over the UK. On day 7 a ridge builds across the UK, with light winds for all
areas except SE England, which lies under northerlies.
As with yesterday's runs, GFS also brings a trough swiftly eastwards on day
6. NW'lies cover the UK as a result, followed by lighter NNE'lies for many
on day 7 as high pressure moves over Scotland.

Looking further afield
The ECM shows high pressure building over England and Wales on day 8,
leaving Scotland and Northern Ireland under southerlies. By day 9 high
pressure builds strongly to the east, leaving a ridge over the UK. England
and Wales lie under mostly light winds while Scotland and Northern Ireland
are affected by southerlies. Day 10 sees SE'lies and southerlies over the UK
as both the high to the east and a ridge over the UK persist.
GFS on day 8 shows a large ridge over the UK, with light winds for all areas
except NW Scotland, which lies under brisk southerlies. On day 9 the ridge
persists, as is the case on day 10; by then winds are a mixture of SE'lies
and ENE'lies over the UK.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles for London show five dry and warm days (at least, warm aloft)
before a trough brings rain and cooler temperatures on the night of the
16th/17th.