Here is a summary of the NWP output for 12z on Saturday.
Issued 05437, 20th March 2007.

The weekend will see dry weather for most, with high pressure to the NE
influencing the UK. Temperatures will be near average and winds will
probably be from the east or southeast for most.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
Strong northerlies and NNW'lies cover the UK, with a ridge to the west. The
ridge moves over Ireland and Scotland tomorrow, leading to further
northerlies elsewhere. By Thursday a mixture of westerlies and NW'lies
covers the UK, with a new ridge building to the west. Friday sees the ridge
move NE'wards, allowing NNE'lies to cover England and Wales. Elsewhere winds
are light due to the ridge.

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 the UK under a ridge, with a relatively weak jet
heading NE'wards over Iceland. At the 500hPa level there's a large upper
high over Scandinavia and a trough across central and southern Europe. ECM
is similar, although the trough over southern Europe is instead a cut-off
low. MetO has an upper high to the NE and a cut-off low over Biscay, with a
trough over SE Europe. NGP has a ridge over Biscay instead and a weaker high
to the NE, while GEM has a stronger high to the NE and shows the UK under an
upper col.
At the surface GFS shows a mixture of southerlies and ENE'lies, with a large
high to the NE. ECM is broadly similar, albeit with stronger NE'lies over
England and Wales due to a tighter gradient. MetO has light easterlies and
SE'lies, again with a high over Scandinavia, while NGP has a ridge and light
winds for all. GEM places the high further to the NE, leading to variable
winds over England and Wales with southerlies elsewhere.

Evolution to T+168
ECM shows easterlies for most on days 6 and 7 as high pressure persists to
the NE.
GFS brings the Scandinavian High slowly westwards, leading to ENE'lies for
most and light winds over Scotland.

Looking further afield
ECM shows a trough bringing SW'lies to Scotland and Northern Ireland on day
8, while England and Wales remain under easterlies. The trough struggles to
move eastwards on day 9, but manages to bring SW'lies across much of the UK.
By day 10 the trough becomes a low over Wales, with light winds across the
UK.
GFS shows SE'lies for most from days 8 to 10 as the Scandinavian High slowly
moves away to the east and low pressure moves in from the SW.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show temperatures around average by the weekend, with largely
dry conditions.