Here is a summary of the NWP output for 12z on Saturday.
Issued 0517z, Christmas Day 2006

**MERRY CHRISTMAS to all readers!**

The models continue to show a change on the way during the coming week. The
high will move away to the east or SE, opening the gates to the Atlantic. By
the end of the weekend it looks like all areas will see wet, windy (and for
many, mild) weather and it's likely to conitnue for some time to come.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
High pressure is centred over the North Sea. Winds are light across
Scotland, with light SE'lies for Northern Ireland and easterlies across
England and Wales. The high declines and moves eastwards tomorrow, leading
to further easterlies for much of England and Wales, with southerlies or
SE'lies elsewhere. By Wednesday the UK lies under southerlies, with high
pressure over eastern Europe. The high moves SE'wards on Thursday, leaving
the UK under SW'lies.

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://85.214.49.20/pics/Rngp1201.gif
The jetstream chart shows a strong jet across eastern Canada and the North
Atlantic, with a marked trough to the west. At the 500hPa level there's an
upper low near southern Greenland and a ridge over France. MetO is similar,
albeit with the ridge further east. ECM has the ridge over the Low
Countries, as is the case with JMA and NGP. GEM has the ridge further east,
with a deeper low to the south of Greenland.
At the surface GFS brings strong SW'lies across the UK with a trough to the
west, while MetO has a trough over the North Sea and also has SW'lies for
all. ECM brings southerlies as the result of a ridge to the east and a
trough to the west; JMA is similar and also shows southerlies. NGP brings
SSW'lies across the UK with a deep low near Iceland and there's little
difference with GEM.

Evolution to T+168
ECM shows heights rising over southern Europe and a trough persisting to the
west. SW'lies are the result on day 6 with a secondary low west of Ireland.
Day 7 sees another secondary low in the same place, with further strong
SW'lies.
GFS also shows strong SW'lies over the UK on days 6 and 7, as heights rise
over southern and central Europe.

Looking further afield
Beyond T+168, ECM shows a strongly zonal outlook. A weak ridge brings
westerlies and SW'lies on day 8, followed by further westerlies on day 9 as
a shallow low moves eastwards to the north. Day 10 sees a low to the west,
with SW'lies for all.
GFS shows a zonal outlook too. On day 8 a deep low to the west of Scotland
brings strong to gale force SW'lies across the UK. The low moves away to the
north on day 9, leaving SW'lies and WSW'lies over the UK. By day 10 a new
low deepens to the SW, with WSW'lies for the UK.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show a marked change in around 5 days time, with 850hPa
temperatures falling, 2m temperatures rising and a fair bit of rain.