Here is a summary of the NWP output for noon on Wednesday.
Issued 0450, 29/10/11

The latter half of the working week will see SE'lies as a trough approaches
from the SW. Intra-model handling of the trough varies but it's likely to
move over the UK, either as a trough (ECM) or a distinct low (GFS); either
way it'll be wet and, once the trough clears, temperatures will fall a few
degrees.

Analysis and evolution to T+120 via GFS
A col covers England and Wales and there are stronger SSW'lies elsewhere.
Tomorrow SW'lies cover the whole of the UK, followed by southerlies on
Monday from a trough to the west. The trough moves eastwards on Tuesday,
with southerlies in advance and SW'lies following behind.

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 ridge over the UK, with a trough to the SW. The
500hPa chart shows a trough extending eastwards to the south of the UK, with
a weak ridge over the North Sea. Upper SE'lies are the result for the UK.
The other models all have southerlies aloft, with the trough to the SW not
extending as far eastwards as with GFS.
At the surface the models show strong southerlies over the UK, with the
exception of GFS which has SE'lies instead.

Evolution to day 7
SE'lies cover the UK on day 6 with ECM, followed by further SE'lies on day 7
for most as a trough moves NE'wards.
GFS brings a secondary low over Wales on day 6, with SE'lies for most areas
as a result. There are SE'lies and SSE'lies on day 7 as another low forms to
the SW.

Looking further afield
ECM shows a col on days 8 to 10, although by day 10 northerlies cover the
eastern half of England as the result of a low over the Netherlands.
GFS days 8 to 10 are unavailable at the time of issue.

Ensemble analysis
http://www.meteociel.com/cartes_obs/...&ville=Londres
GEFS continues to show a marked fall in temperatures after the 2nd.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
The ECM ensembles show mild conditions until the 5th.