**Merry Christmas to all readers!**

Here is a summary of the NWP output for noon on Saturday.
Issued 0526, Christmas Day 2007

The models show high pressure moving eastwards to affect the UK on Sunday,
although the exact positioning is yet to be determined. ECM brings the high
further north than GFS, leading to settled weather for all rather than a
NW/SE split. ECM then keeps the south and east of the UK settled, with
fronts bringing more in the way of cloud and rain for Scotland and Northern
Ireland into next week. GFS shows a similar theme for Monday and New Year's
Day, before some very unsettled conditions push in from the west later in
the week.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
Low pressure lies to the NW of Iceland, with a secondary low over Wales.
Winds are generally SW'lies over the UK. Tomorrow the winds become WSW'lies
for all as low pressure deepens over Iceland. Thursday sees strong to gale
force SW'lies over much of the UK as low pressure persists near Iceland.
There are further SW'lies on Friday as the Icelandic low moves only slowly
eastwards.

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 strong jet over the North Atlantic, with a ridge
to the west of the UK and the jet running SE'wards over the North Sea. At
the 500hPa level there's a ridge over the UK with upper WNW'lies. ECM has a
trough over the UK instead, with upper NW'lies, as is the case with GEM.
MetO and NGP are unavailable as of the time of writing.
At the surface GFS brings westerlies for all, with a weak ridge over
Ireland. ECM has a trough over southern England, with strong SW'lies in
advance and WNW'lies following behind. GEM has westerlies for most with low
pressure over the North Sea.

Evolution to T+168
ECM shows a ridge building across the UK on day 6, with light winds for all.
The high builds to the east on day 7, allowing southerlies and SSW'lies to
affect the UK.
GFS brings SSW'lies across the UK on day 6 as pressure builds over France. A
ridge crosses England and Wales on day 7, with SW'lies and SSW'lies for the
UK.

Looking further afield
Day 8 with the ECM sees further southerlies and SSW'lies for most, with high
pressure over the Czech Republic. On day 9 the high declines with
southerlies and SSW'lies persisting. By day 10 the high builds over northern
France, still with southerlies and SSW'lies over the UK.
Strong southerlies cover the UK on day 8 with GFS due to a trough to the
west. The winds strengthen on day 9, from the SSW, as a low deepens to the
SW of Iceland. By day 10 a trough crosses the UK, with SW'ly gales for
England and Wales and westerly gales for Northern Ireland; Scotland lies
under lighter SW'lies.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The ensembles continue to show a mobile "sine wave" pattern for the week
ahead.