Here is a summary of the NWP output for noon on Sunday.
Issued 0508, 24th March 2010

The new week will start on an unsettled note with low pressure to the west.
During the first half of the week all areas will see some rain and
temperatures are likely to be on the cool side. Neither ECM nor its
ensembles back up the depth of cold as shown by GFS, however.

Analysis and evolution to T+120 via GFS
SSE'lies cover the UK, ahead of a trough to the west. There's little change
tomorrow, but on Friday a trough moves northwards over the UK. Ahead of the
trough there are NE'lies, with southerlies following behind. On Saturday a
low crosses the UK.

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 weak westerly flow over the North Atlantic and
France. At the 500hPa level there are westerlies with a low to the north.
ECM has upper westerlies too, with MetO showing a similar picture. GEM has
westerlies aloft too, as does JMA.
At the surface, GFS brings a col, as does ECM. MetO has SW'lies for most
with a trough over Scotland bringing northerlies there. GEM has a col for
most and JMA shows a shallow low crossing the UK.

Evolution to T+168
ECM brings strong to gale force southerlies on day 6 as a low moves in from
the west. On day 7 the low moves northwards with SSW'ly gales over the UK.
GFS shows cold NW'lies spreading over the UK as low pressure moves away to
the east. On day 7 low pressure approaches Scotland, with cold WNW'lies
across the UK.

Looking further afield
ECM shows a trough moving eastwards on day 8 with WNW'lies in its wake. On
days 9 and 10 there are southerlies and SSE'lies with a low to the west.
GFS brings a series of troughs across the UK on days 8 to 10 with cold
westerlies and NW'lies.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The GEFS shows a cold spell next week.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
The ECM ensembles continue to show temperatures just below average next
week.