Here is a summary of the NWP output for 12z on Wednesday.
Issued 0529z, 14th July 2007.

The latter half of the working week will see a ridge bringing dry weather to
all aresa. However, it's a transitory ridge and the weekend looks unsettled
at this stage.

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 southern Scotland, leading to SW'lies for much of the
UK. Tomorrow a weak ridge covers England and Wales as a low moves over
Biscay, bringing SW'lies for much of the UK. By Monday the Biscay low
deepens and moves northwards, leading to ENE'lies for Scotland and Northern
ireland with SW'lies elsewhere. On Tuesday the low deepens and moves
NE'wards, with SW'lies across the UK.

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 over the western Atlantic but it's
much weaker nearer the UK, which lies under a trough. At the 500hPa level
there's a trough over the North Sea and a weak ridge to the west. MetO shows
a similar setup aloft, while ECM has the upper trough directly over the UK.
NGP brings a flat westerly gradient aloft over the UK, while GEM has a SW'ly
gradient.
At the surface GFS brings WNW'lies and westerlies, with a trough over the
North Sea. MetO is very similar, as is ECM. NGP has a ridge with WSW'lies
for the UK, while GEM shows light winds due to a weak trough.

Evolution to T+168
ECM brings a ridge towards the UK on day 6, with NW'lies. On day 7 the ridge
"topples" SE'wards, over the English Channel, leaving SW'lies for the UK.
GFS also shows a ridge for day 6, this time with WSW'lies. On day 7 a low
deepens to the NW, leading to SSW'lies for all.

Looking further afield
Beyond day 7, the ECM shows a deep upper trough becoming established near
the UK. On day 8 a trough lies to the west, with SW'lies for the UK. On day
9 it moves swiftly eastwards, leaving the UK under NW'lies. The NW'lies ease
somewhat on day 10, but by then notably cold air aloft covers the UK.
GFS also develops a trough near the UK, although it doesn't develop as much
amplitude as with ECM. Day 8 sees SW'lies over the UK with a low to the
north, folloed by WSW'lies on day 9 as the low moves slowly eastwards. Day
10 sees further WSW'lies as a weak ridge crosses the UK ahead of the next
low.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show another 3 warm days, followed by a spell of below average
temperatures aloft. In the long term the temperatures recover to around
average.