Here is a summary of the NWP output for 12z on Friday.
Issued 0526z, 23rd April 2007.

The warm spell will persist across the UK, with all areas seeing
temperatures above average to end the week. Most places will be dry, too,
although some western areas will be at risk of rain as the weekend
progresses.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
SW'lies and southerlies cover the UK, due to a deep low to the west. There's
little change tomorrow or on Wednesday, although by then a secondary low
lies to the west of Scotland. Thursday sees a high build over Northern
Ireland and Scotland, with ENE'lies to the south.

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 large ridge over the UK and at the 500hPa level
there's a large upper high to the east. MetO shows the upper high over the
southern North Sea instead, while ECM has the high further east. NGP has an
upper low over the North Sea instead and GEM is unavailable today.
At the surface GFS has a mixture of easterlies and SE'lies for the UK as the
result of a high over Scandinavia. MetO brings ENE'lies and SE'lies with a
high east of Scotland, while ECM shows easterlies and ESE'lies with a high
to the NE. NGP shows a ridge over the UK with light winds for all.

Evolution to T+168
ECM shows a shallow low over Ireland on day 6, with light winds for the UK.
On day 7 a trough moves in from the west, leading to southerlies and SE'lies
for the UK.
GFS also shows a trough attempting to move in from the west. On day 6 it
covers Ireland, leading to southerlies and SE'lies for the UK. There's
little change on day 7.

Looking further afield
ECM shows trough disruption on days 8 and 9. Day 8 sees southerlies for most
as a trough crosses Ireland. On day 9 the trough becomes a low over the
North Sea, with NW'lies following behind. By day 10 SW'lies and SSW'lies
affect the UK, with low pressure to the WNW.
GFS shows a low over the UK on day 8, followed by southerlies on day 9 from
another low over Ireland. Day 10 sees a secondary low to the south and the
Irish low moves westwards, leading to SE'lies for the UK.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show a generally warm outlook, with a dry end to the week for
northern areas. Further south things are very warm (with 850s 8C above the
mean for at least a week) and mostly dry.