Here is a summary of the NWP output for noon on Wednesday.
Issued 0550, 15th March 2008

The latter half of the working week will see a change to much colder
conditions over the UK, as low pressure moves SE'wards over the North Sea.
At this time of year, the flow is likely to be very unstable, with heavy
(and wintry) showers possible anywhere. Over the higher ground of the north
the showers are likely to fall as snow and there's a chance (albeit a much
lower one) of snow pretty much anywhere. Settling snow is unlikely away from
the north, however, due to the strength of the sun at this time of year.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
SE'lies cover much of the UK, with low pressure to the SW. Tomorrow low
pressure moves over England and Wales, with strong NE'lies to the north. A
ridge moves in from the NW on Monday, leading to northerlies and NNW'lies.
Tuesday sees a ridge persist over the UK, with ENE'lies for England and
Wales and NW'lies 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/Rukm1201.gif
http://85.214.49.20/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows strong jet across the North Atlantic, with a large
blocking ridge to the west. At the 500hPa level there are strong NW'lies,
with a low to the NE. MetO has upper NNW'lies with a ridge to the west,
while ECM brings NNW'lies as well. GEM has upper westerlies with a weak
ridge aloft.
At the surface GFS brings strong WNW'lies, due to a deep low to the ENE of
Scotland. MetO has a ridge over the UK with westerlies and WSW'lies, while
ECM has a mix of NW'lies and WSW'lies, again with a weak ridge over the UK.
GEM shows a ridge as well, this time with westerlies and SW'lies.

Evolution to T+168
ECM brings low pressure east of Scotland on day 6, with strong WSW'lies and
WNW'lies. The low deepens to the east on day 7, leaving strong NNW'lies
across the UK.
A low lies to the east on day 6 with GFS, leading to NW'lies for all. On day
7 a low forms over Biscay, drawing NNE'lies over much of England and Wales.
Elsewhere winds are NNW'lies.

Looking further afield
Moderate northerlies cover the UK on day 8 with ECM, with low pressure to
the east and a large high to the west. There's little change on day 9, but
by day 10 a ridge moves in from the west, bringing westerlies to Scotland
and NNE'lies elsewhere.
Day 8 with GFS shows NW'lies with low pressure to the north and a ridge to
the west. On day 9 milder NW'lies cover the UK as a secondary low moves in
from the NW, followed by further NW'lies and WNW'lies on day 10 as the low
crosses Scotland.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The ensembles show a couple of warm days aloft, followed by a prolonged cool
spell.