Here is a summary of the NWP output for 12z on Thursday.
Issued 0531z, 18th June 2007.

The weekend looks unsettled to begin with, due to low pressure close to the
east. During Sunday pressure will build from the west, with rain becoming
confined to eastern areas.

Analysis and evolution to T+120 via GFS
http://expert.weatheronline.co.uk/pslv_frame.htm
Low pressure lies to the SW and a trough covers England and Wales, bringing
light winds. To the north winds are light ENE'lies. Tomorrow SE'lies affect
the UK as the low to the SW deepens. A trough moves northwards on Wednesday,
leading to SE'lies in advance and southerlies following behind. By THursday
Scotland and Northern Ireland lie under NE'lies as low pressure crosses
Ireland. England and Wales are affected by moderate southerlies.

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 trough over the UK and a large ridge to the
immediate west. At the 500hPa level things are similar, with a strong ridge
from the Azores towards Iceland. An upper low covers Scotland with a trough
over the rest of the UK. MetO shows an Omega block to the NW rather than a
simple ridge, again with a trough over the UK. ECM has a ridge to the west
and a much weaker trough over the UK, while GEM has a high to the WNW and a
trough over the North Sea. NGP brings troughs to the east and west of the
UK, with a weak upper ridge over southern England.
At the surface GFS brings a mixture of northerlies and NW'lies, with low
pressure over the North Sea. MetO shows a shallow trough over much of the
UK, with light winds for all areas except Northern Ireland, which lies under
moderate NW'lies. ECM brings a trough anf light winds over England and
Wales, with northerlies elsewhere. GEM shows a low over England and Wales
instead, again with northerlies for Scotland and Northern Ireland. NGP shows
a large but slack low to the NE, with SW'lies for the Midlands south and
NW'lies further north.

Evolution to T+168
ECM shows high pressure building over the Azores, with NW'lies for the UK on
days 6 and 7.
GFS also brings high pressure over the Azores. On day 6 low pressure fills
to the south of the UK, leading to NNE'lies and northerlies. By day 7 the
winds become NW'lies as a ridge "topples" to the west.

Looking further afield
Day 8 on the ECM shows a ridge from the west and NW'lies on day 8, followed
by westerlies on day 9 for much of the UK from a low to the north. Day 10
sees light NW'lies with a ridge to the west.
GFS shows largely settled contditons for the UK on days 8 to 10, with high
pressure to the WSW. Winds are initially NW'ly but back westerly by day 10.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show 5 days of average or above average temperatures, followed
by a notably cool few days.

On Jun 18, 6:32 am, "Darren Prescott"
wrote:
Here is a summary of the NWP output for 12z on Thursday.
Issued 0531z, 18th June 2007.

The weekend looks unsettled to begin with, due to low pressure close to the
east. During Sunday pressure will build from the west, with rain becoming
confined to eastern areas.

I'm guessing like this Saturday, any rain will take the form of
showers and by Saturday evening, particularly after 7pm the showers
will melt away and it'll likely be dry (if cold after dark). I ask as
I'm leading a walk on Saturday evening which is an annual event and
the weather is always either one extreme or the other....

Nick