Here is a summary of the NWP output for noon (GMT) on Friday.
Issued 0518z, 25th August 2008

The weekend will see warm (if not hot) conditions over much of England and 
Wales giving way to less settled and cooler conditions as a trough moves in 
from the west. Scotland and Northern Ireland are likely to stay cooler and 
less settled throughout.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
LOw pressure lies to the south of Iceland, with SSW'lies over the UK. 
Tomorrow the SW'lies persist as the low fills, with further SW'lies on 
Wednesdayy. Thursday sees the winds fall light over England and Wales as 
pressure rises, with SW'lies elsewhere.

T+120 synopsis
http://85.214.49.20/pics/Rtavn12014.png / 
http://85.214.49.20/pics/Rtavn1201.png
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 ridge over the UK with a deep trough to the 
west. At the 500hPa level there's a southerly flow, while MetO has NW'lies 
aloft and a ridge. SW'lies aloft cover the UK with ECM, which has an upper 
high over Belgium. GEM shows upperr southerlies as per GFS.
At the surface GFS shows SE'lies and SSE'lies due to a large high to the 
east and a trough over Biscay. MetO has a large ridge over the UK and light 
winds for all. ECM brings southerlies due to a trough to the west and GEM 
has southerlies as well.

Evolution to T+168
Day 6 with ECM brings further southerlies as low pressure deepens to the SW> 
Day 7 sees the low move over Scotland with SW'lies and WSW'lies elsewhere.
SE'lies cover much of the UK on day 6 with GFS as a trough crosses Ireland. 
WSW'lies affect the UK on day 7 as pressure builds to the south.

Looking further afield
On day 8 with ECM southerlies return, with low pressure to the west. By day 
9 a deep low lies to the NW with SW'lies for all. Day 10 sees southerlies as 
the low moves NE'wards.
Southerlies and SW'lies cover the UK on day 8 with GFS as low presure lies 
to the west. Day 9 sees WSW'lies as low pressure deepens to the north and on 
day 10 low pressure crosses Scotland, with SW'lies and westerlies elsewhere.

Ensemble analysis 
(http://91.121.94.83/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=0&ville=Londres)
The ensembles show a warm and dry week ahead.