Here is a summary of the NWP output for 12z on Saturday.
Issued 0519z, 24th July 2007

There are signs of a change on the way. The weekend will see low pressure
and rain clearing eastwards, followed by a ridge from the Atlantic. The jet
stream will head north and there should be a few largely dry, sunny and warm
days across much of the UK next week.

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 lies to the east, leading to NW'lies over the UK. A weak ridge
moves eastwards and by tomorrow winds are SW'lies ahead of the next low.
SSW'lies affect the UK on Thursday as low pressure moves closer. On Friday
the low passes ENE'wards to the north of Scotland, leading to WSW'lies for
all.

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 sharp trough to the west and a ridge near
Greenland. The jet runs across England and Wales. At the 500hPa level
there's a flat westerly gradient over the UK, as is the case with ECM. NGGP
has a trough just to the west of the UK, while GEM also has a trough to the
west.
At the surface GFS brings light winds and a weak ridge over the UK. ECM also
has a ridge and light winds, while NGP brings a low over Ireland. Easterlies
cover Scotland, NE'lies cover Northern Ireland and the rest of the UK lies
under SW'lies. GEM shows a trough over Scotland and Northern Ireland, with
SW'lies elsewhere.

Evolution to T+168
ECM brings low pressure across Scotland on day 6, followed by NW'lies and a
high to the west on day 7.
GFS shows NW'lies on day 6 as a ridge moves in from the west. The ridge
crosses the UK on day 7, bringing light winds for most.

Looking further afield
Beyond day 7, the ECM brings high pressure over much of the UK on days 8 to
10, with northern Scotland staying under SW'lies.
Days 8 to 10 on GFS also show high pressure dominating the UK, although
northern Scotland again lies under SW'lies.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show temperatures generally below average aloft for 5 days or
so, followed by a warmer interlude.