Here is a summary of the NWP output for noon on Wednesday.
Issued 0534, 13th March 2010

A NW/SE split will be evident for much of the week, with high pressure close
to the SE keeping things largely dry there and with a greater risk of rain
the further north and west you are. By the weekend a change in type could be
on the cards as the jet moves south again, thus bringing the rain risk
further south too.

Analysis and evolution to T+120 via GFS
NW'lies cover the UK with a high to the west. Tomorrow there are WNW'lies as
the high drifts slowly SE'wards, followed by westerlies on Monday. Tuesday
sees a ridge over the UK with westerlies for all.

T+120 synopsis
http://91.121.93.17/pics/Rtavn12015.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 UK, with the jet
resetting to a more southerly track upstream. ECM has SW'lies aloft due to a
shortwave trough over Ireland, while MetO has upper westerlies and a zonal
flow over western Europe. GEM brings upper SW'lies with a ridge to the east
and JMA has upper SW'lies too.
At the surface, GFS brings southerlies and a weak trough over Scotland. ECM
also brings southerlies, while MetO has SW'lies and also a weak trough for
Scotland. GEM has southerlies and JMA has SSW'lies, both with a trough to
the north.

Evolution to T+168
ECM shows WSW'lies on day 6 as a weak ridge moves eastwards, followed by
SSW'lies on day 7 as another trough crosses Scotland.
GFS brings southerlies on day 6 as a low deepens to the SW. On day 7 the low
moves northwards and a trough extends towards the UK, with easterlies and
ESE'lies as a result.

Looking further afield
ECM shows a low over England on day 8 with NE'lies to the north. NE'lies
affect most areas on day 9 due to a high over Scotland and on day 10 the
high extends over most of the UK.
GFS has low pressure over the Scottish borders on day 8, leading to SW'lies
ot the south and NE'lies to the north. A col covers the UK on day 9 and on
day 10 southerlies pick up ahead of a low to the west.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The GEFS shows above average means later next week, albeit mainly due to
warm nights.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
The ECM ensembles show temperatures not far from average for the forseeable
future.