Here is a summary of the NWP output for 12z on Saturday.
Issued 0521z, 7/11/06

The models continue to show a north/south split on the way, with largely
settled conditions for much of England and Wales. Elsewhere winds will be
stronger and there's a greater risk of rain.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
High pressure lies to the SE with a ridge over England and Wales. Winds are
light there but elsewhere SW'lies or southerlies affect Scotland and
Northern Ireland. A trough affects Scotland and Northern Ireland tomorrow,
with SW'lies elsewhere and by Thursday a WNW'ly flow covers the UK as the
trough moves away to the east. Friday sees southerlies and SSW'lies as high
pressure moves eastwards and builds over SE England.

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.jpg /
http://85.214.49.20/pics/Rukm1201.jpg
http://85.214.49.20/pics/Recm1201.jpg /
http://85.214.49.20/pics/Rngp1201.jpg
The GFS jetstream chart shows a ridge to the west of the UK, with a strong
NW'ly flow over the eastern half of the UK and the North Sea. At the 500hPa
level that translates to a ridge to the west, with a NW'ly gradient over the
UK. JMA, NGP and GEM also show a ridge to the west but with the exception of
JMA there's less of a NW'ly flow. MetO was unavailable at the time of
writing.

At the surface, GFS shows a high over Biscay and a ridge northwards to
Iceland, with NW'lies across the UK. ECM shows WNW'lies instead with less
ridging towards Iceland and JMA shows stronger NW'lies with a discrete high
to the west. NGP brings westerlies for all with low pressure west of Iceland
and the Canadian run also shows westerlies, this time with a weak ridge west
of Iceland.

Evolution to T+168
ECM brings SW'lies across the UK on day 6 as the upper ridge and surface
high move eastwards. By day 7 both decline and move slowly eastwards, with
further SW'lies for the UK.
GFS also shows the ridge progressing eastwards and declining, with light
winds for all on day 6 and light SW'lies or southerlies on day 7.

Looking further afield
ECM out to 10 days shows a ridge over England and Wales from days 8 to 10,
with high pressure slowly moving eastwards. Winds are light over England and
Wales, with light to moderate SW'lies over Scotland and Northern Ireland.
The GFS brings southerlies for all on day 8 as the high moves eastwards and
a trough develops to the west. The trough deepens into a low to the SW of
Ireland on day 9 with SW'lies for England and Wales and light winds
elsewhere. Day 10 sees a high build to the NW with northerlies across the
UK.

Ensemble analysis (http://85.214.49.20/wz/pics/MT8_London_ens.png - last
night's 18z)
The GFS ensembles show general agreement of above-average temperatures aloft
from the 11th onwards, but there's a jumble of spaghetti and there are signs
of a shortlived cooler period, reflecting incursions of colder air behind
troughs.