Here is a summary of the NWP output for noon on Monday.
Issued 0457, 25th March 2010

The first half of next week will see low pressure close to or over the UK
with strong winds and rain for all at times. Temperatures by day are likely
to be just below average, with night time lows above average due to the
cloud and rain. Once again GFS is a much colder suite than ECM but as GFS is
backing away from the cold, albeit slowly, it's likely the ECM's scenario of
just-below-average temperatures will be the correct one.

Analysis and evolution to T+120 via GFS
SSE'lies cover the UK, with low pressure to the SW and a low to the NW as
well. Southerlies affect the UK tomorrow as a trough moves northwards,
followed by a col on Saturday. Sunday sees WSW'lies for all with a low to
the NE.

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 to the south of the UK. At
the 500hPa level there are southerlies with a trough extending southwards to
the west of the UK. ECM has upper westerlies, while MetO has a trough to the
west and upper SW'lies. JMA also shows upper SW'lies.
At the surface, GFS brings a low over the Westcountry with southerlies for
much of England and Wales and strong NE'lies elsewhere. ECM shows SE'lies
with a low to the west and MetO brings a mixture of SE'lies and easterlies
due to a low over the Celtic Sea. JMA has a col over the UK.

Evolution to T+168
ECM brings a low over England and Wales on day 6 with easterlies to the
north. On day 7 the low moves away to the NE only to be replaced by another
low over the English Channel.
GFS shows strong to gale force NW'lies and westeries on day 6 with a deep
low over the North Sea. On day 7 the low moves away ENE'wards, leaving cold
westerlies over the UK.

Looking further afield
ECM shows weak ridge and NW'lies on day 8. Low pressure moves slowly
eastwards over Northern Ireland and Scotland on days 9 and 10, with strong
westerlies to the south.
GFS brings WSW'lies on day 8 with a low to the NE. On day 9 there are
SW'lies and on day 10 a secondary low deepens over the English Channel, with
a low persisting over Scotland.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The GEFS shows a cool spell next week, having backed away from the depth of
cold shown yesterday.

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