Here is a summary of the NWP output for noon on Friday.
Issued 0439z, 16/05/11

The end of the working week will see SW'lies giving way to southerlies for a
time as a ridge moves NE'wards to the south, probably covering much of
England and Wales for a time. It'll be warm in the sunshine with the highest
chance of rain remaining in the NW.

Analysis and evolution to T+120 via GFS
WSW'lies cover the UK, the result of a large high to the SW. There are
further WSW'lies tomorrow, followed by SW'lies on Wednesday as a low deepens
to the NW. Thursday sees a ridge and light winds over England and Wales,
with WSW'lies elsewhere.

T+120 synopsis
http://www.wetterzentrale.de/wz/pics/Rtavn12014.png
http://www.wetterzentrale.de/wz/pics/Rtavn1201.png
http://www.wetterzentrale.de/wz/pics/Rukm1201.gif
http://www.wetterzentrale.de/wz/pics/Recm1201.gif
http://www.wetterzentrale.de/wz/pics/Rjma1201.gif
The jetstream chart shows a strong jet heading NE'wards over Scotland and
Northern Ireland. At the 500hPa level there are SW'lies aloft, as is the
case with MetO
At the surface the models all show a ridge to the south. GFS has the ridge
extending over England and Wales, while the other runs show less of an
influence with SW'lies across the UK.

Evolution to T+168
Days 6 and 7 with ECM show SW'lies with a low to the NW.
Southerlies cover the UK on day 6 with GFS, followed by a col on day 7.

Looking further afield
A col covers the UK on day 8 with ECM, followed by a trough moving
northwards on day 9. Day 10 sees another col.
GFS brings a col on day 8, followed by NW'lies on day 9. There are further
NW'lies on day 10.

Ensemble analysis
http://www.meteociel.com/cartes_obs/...&ville=Londres
The GEFS continues to snow near-normal maxima for the working week, followed
by a slow rise.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
ECM shows stronger signs of a warm spell this weekend.