Here is a summary of the latest NWP output for noon on Christmas Day. Issued
0615z, 21/12/04.

The models continue to show a shortlived cold snap over Christmas Day and
Boxing Day, with the GFS precipitation charts showing snow across most of
the UK. However, there's still a fair bit of time for details to change so a
White Christmas shouldn't be taken for granted! Beyond that, much milder air
looks like pushing in from the west on Monday or Tuesday, but details vary
considerably between models. As ever, more runs are needed.

ECMWF: http://64.246.48.81/pics/Recm1201.gif
A deep low lies to the north of the UK, bringing westerlies and WNW'lies.
The winds become NNW'lies as the low sinks over the North Sea on Boxing Day,
followed by much milder westerlies as a ridge topples SE'wards on day 7.

MetO: http://www.wetterzentrale.de/pics/Rukm1201.html
The Met Office run shows strong to gale force northerlies and NW'lies across
the UK, with low presure to the east of Scotland. A weak ridge sinks
SE'eards over Ireland and western Britain at T+144, leading to NNW'lies for
most.

GFS: http://expert.weatheronline.co.uk/
A trough covers the UK, with westerlies in advance and NW'lies following
behind. 850hPa temperatures are below -5C over all areas except parts of
southern and SW England. NW'lies cover the whole of the UK by Boxing Day as
low pressure fills to the SW of Norway. T+144 sees the low sink over the
Netherlands to bring strong northerlies over England and Wales, with NW'lies
elsewhere due to a toppling ridge. The chart for day 7 is unavailable, but
by day 8 strong westerlies cover the UK with a deep low to the east of
Iceland. NW'lies cover the UK on day 9 as a trough moves eastwards, followed
by more NW'lies and northerlies on day 10 with a low over southern Scotland.

GEM: http://www.meteocentre.com/models/glb00_120.html
The UK lies under a blast of northerlies, with strong winds dur to a ridge
to the west and a trough over the North Sea. The ridge topples over the UK
at T+144 to bring northerlies and westerlies, followed by mild westerlies
for all on day 7.

GME/DWD:
http://www.wetter.com/home/img/sat/g...210000_120.gif
Low pressure is centred over the North Sea, bringing northerlies and NW'lies
for the UK. The low moves slowly SE'wards at T+144 to bring further
northerlies, followed by NE'lies for England and Wales as it sinks further
SE'wards on day 7. By then SW'lies from a low to the NE of Iceland are
affecting Scotland.

JMA: http://www.wetterzentrale.de/pics/Rjma1201.html
An area of low pressure covers northern Scotland, resulting in NNW'lies and
westerlies across the UK. The low moves over the North Sea at T+144 to bring
northerlies and NNW'lies, followed by lighter northerlies for England and
Wales at T+168 as a ridge topples SE'wards. By now, Scotland and Northern
Ireland lie under SW'lies and by day 8 the whole of the UK lies under
WSW'lies.

NOGAPS: http://129.13.102.67/wz/pics/ngp10.prp.120.europeg.gif
Cyclonic WNW'lies cover the UK, with low pressure to the NE and a trough to
the west of Scotland. By T+144 the winds become stronger northerlies as low
pressure sinks southwards over the North Sea.

GM CPTEC: http://www.cptec.inpe.br/prevnum/Global126_sx6_Gl.shtml
The Brazilian run shows a similar setup, with westerlies for all and a low
to the NE.

KMA: http://www.kma.go.kr/kma03/gif/g21nh_smsr_120.gif
The Korean run shows strong westerlies with a deep low to the east of
Iceland.