Here is a summary of the NWP output for noon on Monday.
Issued 0533, 27th February 2009

The latter half of the working week will see a deep low cross the UK,
bringing strong winds and rain to most areas. The exception will be higher
ground in the north, where the rain will fall as snow - there may be
blizzards over the peaks. Temperatures will be at or below average
generally.

Analysis and evolution to T+120 via GFS
WSW'lies cover the UK, with high pressure to the south. SW'lies affect the
UK tomorrow ahead of a trough to the west, then on Sunday the trough moves
eastwards across the UK. Ahead of the trough winds are southerlies, with
westerlies following behind. There are WSW'lies on Monday as the trough
moves away to the east.

T+120 synopsis
http://91.121.93.17/pics/Rtavn12014.png /
http://91.121.93.17/pics/Rtavn1201.png
http://91.121.93.17/pics/Rukm1201.gif
http://91.121.93.17/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a very syrong and zonal jet across the Atlantic
and the UK. AT the 500hPa level there's an upper low to the west of Scotland
and strong upper WSW'lies for the UK. MetO instead has an upper trough over
the UK, while ECM brings upper westerlies with a low over Iceland. GEM has
an upper low south of Iceland and upper SW'lies for the UK.
At the surface, GFS shows strong to gale SW'lies with a deep low west of
Scotland. MetO has a weaker low in the same place, with light SSE'lies for
Scotland and moderate to strong WSW'lies elsewhere. ECM has SW'lies for all
with its low further NW and GEM brings a trough over Ireland with a mixture
of SSW'lies and southerlies for the UK.

Evolution to T+168
On day 6 ECM shows a deep low to the NW and SW'lies for all. The low crosses
Scotland on day 7, leading to SE'lies for much of Scotland and WSW'lies or
SW'lies for the rest of the UK.
GFS brings strong to gale NW'lies on day 6 with low pressure over the North
Sea. The low moves northwards and fills on day 7, leading to lighter
NW'lies.

Looking further afield
ECM brings low pressure over East Anglia on day 8, with northerlies and
NW'lies for the UK. The low fills to the SE on day 9, with NNW'lies as a
result. NNW'lies and NW'lies cover most of the UK on day 10 as a ridge moves
in from the west.
Day 8 with GFS has WNW'lies for all withy low pressure to the north and a
secondary low to the SW. A ridge moves in from the west on day 9, bringing
NW'lies. The ridge crosses the UK on day 10, with NW'lies in advance and
milder SW'lies following behind.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The ensembles show a cool spell next week.