Here is a summary of the NWP output for 12z on Wednesday.
Issued 0524z, 21st July 2007

The latter half of the working week will see unsettled weather across the UK
with low pressure close to Scotland.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
Low pressure covers England and Wales, leading to NNE'lies over much of the
UK. Tomorrow the low moves over Scotland and Northern Ireland with SW'lies
elsewhere. On Monday the Scottish low fills over Aberdeen while a new low
deepens to the SW. Winds are light across much of the UK, but moderate
SE'lies cover SW England. On Tuesday the low fills to the east, leaving the
UK under NW'lies.

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 across the North Atlantic and the UK.
At the 500hPa level there's a low to the WNW, as is the case with MetO. ECM
also shows a low to the WNW and a ridge over the North Sea. GEM is a carbon
copy of ECM, while NGP shows a low to the WNW.
At the surface GFS brings a deep low to the west of Scotland with SW'lies
and SSW'lies for the UK. MetO also shows a low to the WNW and SW'lies. ECM
keeps the low further to the west, with southerlies over the UK and a ridge
to the east. GEM is very similar to ECM, while NGP also brings SW'lies with
a low to the WNW.

Evolution to T+168
ECM shows a low moving NE'wards to the north of the UK, leading to SW'lies
on days 6 and 7.
GFS brings a low to the NW with SW'lies for days 6 and 7.

Looking further afield
Beyond day 7, the ECM brings a ridge over the UK on day 8, followed by
southerlies on day 9 as the ridge moves eastwards. Day 10 sees a low to the
WNW and SW'lies for all.
Low pressure fills to the north on day 8 with GFS, bringing WSW'lies.
Westerlies cover the UK on day 9 as a weak ridge moves eastwards, followed
by SW'lies on day 10 as a ridge builds over France.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show temperatures a little below average aloft over the next
few days, followed by a wide scatter from day 7 onwards.