Here is a summary of the latest NWP output for noon (GMT) on Saturday.
Issued 0501z, 25th August 2009.

Low pressure will be close to the UK for Saturday, with rain moving
eastwards over much of the UK. As ever, it'll be much lighter in the SE.
During Sunday a ridge will move in from the west and Monday looks settled
across much of England and Wales. However, Scotland and Northern Ireland
will be at risk of rain from a nearby trough.

ECMWF: http://www.wzkarten.de/pics/Recm1201.gif
A deep low lies to the north, bringing moderate to strong westerlies over
the UK. The winds become WNW'lies on day 6 as the low moves away to the
east, followed by southerlies and a ridge on day 7.

MetO: http://www.wzkarten.de/pics/Rukm1201.gif
A westerly flow covers the UK, the result of a deep low west of Norway. On
day 6 a ridge crosses England and Wales, with SW'lies for all.

GFS: http://www.wzkarten.de/pics/Rtavn1201.png
A weak ridge covers the UK, with WSW'lies as a result. The winds become warm
SSW'lies on day 6, with high pressure to the east. On day 7 a trough crosses
the UK, with light winds for most.

GEM: http://www.wzkarten.de/pics/Rgem1201.gif
The Canadian run brings westerlies for all and a high to the SW.

JMA: http://www.wzkarten.de/pics/Rjma1201.gif
The Japanese run has westerlies for all, similar to GEM.