Here is a summary of the NWP output for noon on Thursday.
Issued 0546, 22nd November 2009.

In summary, the change to cooler (relative to recent) conditions is still on
the way, as the jet moves southwards. Low pressure will be close to the UK
to end the working week with all areas seeing rain, especially so in the
north and west.

Analysis and evolution to T+120 via GFS
Southerlies cover the UK, with a deep low to the west. The low moves
NE'wards tomorrow, leading to strong to gale force SW'lies over the UK. A
weak ridge brings a respite on Tuesday, with lighter WSW'lies, before
strengthening SW'lies move in from the west on Wednesday.

T+120 synopsis
http://91.121.93.17/pics/Rtavn12014.png /
http://91.121.93.17/pics/Rtavn1201.png
http://91.121.93.17/pics/Rukm1201.gif
http://91.121.93.17/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a strong jet over the North Atlantic, with the jet
heading ESE'wards towards Iberia. There's an upper trough over the UK. At
the 500hPa level there's also a trough, with westerlies aloft. ECM also has
westerlies aloft and a trough over the UK, as is the case with MetO. GEM has
WSW'lies aloft with the centre of the trough further west, while JMA is
similar to the others with a trough and westerlies over the UK.
At the surface, GFS brings WSW'lies and a weak trough. ECM has a trough to
the west and stronger SW'lies, as is the case with MetO and GEM. JMA has a
trough over eastern areas of the UK with westerlies as a result.

Evolution to T+168
ECM shows SW'lies on day 6 as a weak low crosses Scotland. On day 7 a weak
ridge brings westerlies to much of England and Wales, with a col for
Scotland and southerlies for Northern Ireland.
GFS brings a trough in from the west on day 6, with southerlies in advance
and westerlies following behind. On day 7 low pressure covers Scotland and
Northern Ireland, leading to SW'lies elsewhere.

Looking further afield
ECM shows southerlies over England and Wales on day 8 as a low deepens to
the SW. ENE'lies cover Scotland and Northern Ireland. On day 9 low pressure
lies over the North Sea, with a mixture of NW'lies and SW'lies for the UK.
Day 10 sees the low fills to the NE, with westerlies for all.
Days 8 to 10 with GFS show an upper low moving slowly NE'wards from the UK.
On day 8 a surface low covers Scotland, with light westerlies elsewhere. The
low remains in situ on day 9, with stronger westerlies elsewhere. By day 10
the low deepens to the NE, leaving strong westerlies and NW'lies over the
UK.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The ensembles show a relatively average 5 to 7 days after Wednesday.