Here is a summary of the NWP output for 12z on Sunday.
Issued 0456z, 16th May 2007.

After a changable weekend, next week will start in much the same vein, with
scattered showers and low pressure close by. By the middle of the week
though the models split, with GFS very keen on bringing hot conditions from
the Continent over the UK. ECM shows the polar opposite though, with zonal
westerlies continuing out to day 10. As ever, more runs are needed.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
A mixture of northerlies, NW'lies and westerlies covers the UK, with a ridge
to the west. Tomorrow a trough crosses Scotland, leading to SE'lies there
and SW'lies or westerlies elsewhere. By Friday SW'lies affect all areas,
with complex low pressure to the north and west. On Saturday the lows merge
to the north, with strong to gale force WSW'lies as a result.

T+120 synopsis
http://85.214.49.20/pics/Rtavn12015.png /
http://85.214.49.20/pics/Rtavn1201.png
http://85.214.49.20/pics/Rjma1201.gif /
http://85.214.49.20/pics/Rukm1201.gif
http://85.214.49.20/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a very strong jet across the North Atlantic and a
trough over the UK. At the 500hPa level there's also a trough over the UK,
as is the case with the other runs.
At the surface GFS brings westerlies and SW'lies, with a weak trough over
the North Sea. MetO and ECM both show cyclonic WSW'lies, with a trough over
the UK. GEM brings westerlies, while NGP has SW'lies and a low to the NNW.

Evolution to T+168
ECM brings WSW'lies on days 6 and 7, with low pressure persisting to the NW.
GFS shows strong WSW'lies for day 6 due to a deep low to the north, followed
by further WSW'lies on day 7.

Looking further afield
Day 8 on the ECM shows SW'lies and a trough to the west. On day 9 the trough
crosses the UK, leading to westerlies, with further westerlies on day 10.
GFS shows a ridge over England and Wales on day 8 with SW'lies elsewhere. On
day 8 the ridge builds and moves NE'wards, leading to hot ESE'lies. The
winds become SW'lies on day 10 as high pressure builds over Scandinavia.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show a marked hot spell on the way next week.