Here is a summary of the NWP output for 12z on Wednesday.
Issued 0518z, 17th March 2007.

The end of the next working week will be quite bleak in some places, with
cold NE'lies likely to set in as pressure builds strongly over Scandinavia.
Sheltered western areas will fare the best, with some strong spring
sunshine, whereas eastern areas are likely to see more in the way of cloud
and cold rain coming in from the North Sea.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
Westerlies cover the UK, with the Azores High to the SW. The high
retrogresses during today, with westerlies for most by midnight tonight.
During tomorrow a very cold airmass will move southwards over the UK, with
westerlies in advance and NW'lies following behind. Monday sees NW'lies for
all, with the winds veering during the day. During Tuesday the winds remain
as NNW'lies for all as a ridge moves in from the west.

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 meridonal pattern with part of the jet heading
southwards over the UK. To the west is a large ridge, associated with a
500hPa ridge, while to the east is a trough. ECM is broadly similar, as is
MetO - the differences are regarding the strength of the upper ridge to the
west. NGP has a stronger ridge with a link NE'wards to a ridge over Russia,
while GEM has a ridge to the west and a trough to the east, much as with the
other runs.
At the surface GFS shows light winds for all and a col, while ECM has a
ridge over the Irish Sea. Winds are NNW'lies in advance of the ridge with
SW'lies for Scotland and Northern Ireland. MetO has NW'lies and NNW'lies and
a weak ridge over the UK, while NGP brings NNE'lies with a stronger ridge to
the west. GEM shows a weak ridge over Ireland with SW'lies for Scotland and
Northern Ireland; elsewhere winds are NNW'lies.

Evolution to T+168
ECM brings light northerlies over the UK on day 6 with a ridge to the west,
followed by NE'lies on day 7 as the ridge moves NE'wards and builds.
GFS shows ridging occuring a day earlier than ECM, with a large Scandinavian
High and NE'lies for all on day 6. The high builds on day 7, drawing further
NE'lies over the UK.

Looking further afield
ECM shows further NE'lies on day 8, followed by easterlies on day 9 as a
trough disrupts and a low runs along the English Channel. By day 10 a new
low approaches from the SW, bringing easterlies for all.
GFS shows NE'lies persisting on day 8 as the Scandinavian High remains in
situ. Day 9 sees ENE'lies as low pressure crosses France, followed by
NE'lies again on day 10 as the low moves NE'wards over Germany.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles continue to show a cold plunge, followed by a gradual warming.