Here is a summary of the NWP output for noon on Saturday.
Issued 0447, 11/10/11

In summary, early next week a trough will move eastwards with rain for all
as a result. ECM shows temperatures varying quite widely from north to
south, while GFS has cold air for all after Tuesday.

Analysis and evolution to T+120 via GFS
Gusty WSW'lies cover the UK, which lies between a low to the north and a
high to the south. Tomorrow there's a col over Scotland and WSW'lies
elsewhere, followed by a ridge and light winds on Thursday. Friday sees
southerlies and SE'lies with a high to the east.

T+120 synopsis
http://www.wetterzentrale.de/wz/pics/Rtavn12014.png
http://www.wetterzentrale.de/wz/pics/Rtavn1201.png
http://www.wetterzentrale.de/wz/pics/Rukm1201.gif
http://www.wetterzentrale.de/wz/pics/Recm1201.gif
http://www.wetterzentrale.de/wz/pics/Rjma1201.gif
The jetstream chart shows a meridonal pattern with a marked trough to the
west and a ridge to the east. SSW'lies aloft cover the UK. At the 500hPa
level there are SW'lies on all the runs.
At the surface GFS brings SSW'lies with a trough to the west, as is the case
with the other runs.

Evolution to day 7
A trough moves eastwards on day 6 with ECM, leading to WSW'lies. There are
further WSW'lies on day 7.
The UK lies under southerlies on day 6 with GFS, due to to a trough to the
west. The trough crosses the UK on day 7, resulting in colder westerlies.

Looking further afield
ECM brings a secondary low over Scotland on day 8 with WSW'lies elsewhere.
Day 9 sees WSW'lies for all and a weak ridge to the west brings WNW'lies on
day 10.
There's a cold col over the UK with GFS on day 8, followed by southerlies
from a complex low to the west on day 9. Day 10 sees the lows merge over the
UK.

Ensemble analysis
http://www.meteociel.com/cartes_obs/...&ville=Londres
GEFS shows a gradual fall in temperatures from Friday onwards.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
The ECM ensembles are unavailable today.