Here is a summary of the NWP output for 12z on Saturday.
Issued 0546z, 12th June 2007.

The weekend still looks unsettled across the UK, with temperatures not far
from average. Into next week the models are split, with GFS keeping a slow
moving low close to the UK (and thus with unsettled weather). ECM is more
progressive and brings in a high from the NW and a slight risk of frost to
the more sheltered parts of the UK.

Analysis and evolution to T+120 via GFS
http://expert.weatheronline.co.uk/pslv_frame.htm
The UK lies under a col, as is the case tomorrow. A trough moves up from the
south on Thursday, with easterlies for most as a result. Some unusually cold
air approaches Scotland, with the Northern Isles under sub -5C 850 air. By
Friday the trough moves northwards slowly, introducing SE'lies for much of
England and Wales with easterlies persisting elsewhere.

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 jet stream chart shows a large trough over the UK and a strong jet
across the western half of the North Atlantic. At the 500hPa level there's a
trough to the west and a weak ridge over England and Wales. MetO shows
higher heights over the UK with the trough further to the west, while ECM
shows an upper trough over the UK. GEM has a trough over the UK too and NGP
shows a low to the north instead.
At the surface GFS brings moderate to strong westerlies and WSW'lies over
the UK with a low east of Scotland. MetO has low pressure further south,
near Newcastle; this leads to SW'lies for southern England and northerlies
for much of the UK. ECM has a low centred over the Scottish borders, while
GEM shows low pressure further SE with a MetO-like setup of northerlies for
most. NGP shows a col and light winds.

Evolution to T+168
ECM shows the upper trough to the west filling and moving eastwards as
heights rise near Iceland. On day 6 complex low pressure surrounds the UK,
with centres to the NE, over Scotland and to the west. Winds are light
SW'lies or WSW'lies for most. By day 7 low pressure fills over southern
Ireland, with southerlies and SE'lies across the UK.
GFS brings low pressure west of the UK and keeps it there on days 6 and 7,
as high pressure builds to the west of Greenland. A col covers most of the
UK on day 6, with strengthening SSE'lies ahead of the low on day 7.

Looking further afield
Day 8 on the ECM shows low pressure atop the UK. On days 9 and 10 the low
moves away to the NE as pressure builds to the NW. Northerlies and NW'lies
cover the UK as a result.
GFS shows low pressure to the west very slowly moving NE'wards on days 8 to
10, with southerlies for all on day 8. On day 9 SW'lies cover the UK and on
day 10 the winds become WSW'lies.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show a few warm days before 850 temperatures return to normal
(for southern areas), with a notable cold blip coming midweek for northern
areas (followed by a return to normal).