Here is a summary of the latest NWP output for noon on Wednesday. Issued
0709z, 13/12/03.

ECMWF: http://www.wetterzentrale.de/pics/Recm1201.gif
SW'lies and SSW'lies cover the UK, with high pressure to the SE and a
smaller high to the WSW. The latter builds and moves ENE'wards at T+144,
resulting in westerlies for all. There's little change at T+168, with a
continuation of westerlies.

MetO: http://www.wetterzentrale.de/pics/Rukm1201.html
The Met Office run shows southerlies and SSW'lies, due to a deep Iicelandic
low and high pressure over eastern Europe. A small high lies to the west of
the UK; by T+144 it builds and moves NE'wards, leaving the UK under light
winds. The winds are SE'lies over England and Wales, with variable winds
elsewhere.

GFS: http://www.wetterzentrale.de/pics/Rtavn1081.gif
A deep low covers Iceland and high pressure lies to the SE of the UK,
resulting in southerlies and SW'lies. There's little change at T+120, as the
Icelandic low moves ENE'wards. 850hPa temperatures range from freezing over
NW Scotland to +6C over SW England. A ridge covers the UK at T+44, with
light winds for all. By T+168 a high builds over Scotland, with easterlies
and SE'lies elsewhere. The high then sinks SE'wards on day 8, with SW'lies,
SSW'lies and SE'lies over the UK. Day 9 sees a low over southern Norway,
with a trough over the North Sea. As a result, Scotland lies under
northerlies, with westerlies and NW'lies elsewhere. A new trough covers
Ireland on day 10, bringing southerlies there. Meanwhile, England, Scotland
and Wales lie under a broad ridge, with light winds.

GEM: http://www.wetterzentrale.de/pics/Rgem1201.gif
The Canadian run also shows SSW'lies and SW'lies over the UK, with low
pressure over Iceland. 850hPa temperatures range from +2C over NW Scotland
to +6C over East Anglia. By T+144 strong westerlies affect the UK, as the
low moves ENE'wards.

JMA: http://www.wetterzentrale.de/pics/Rjma1201.html
As with the other runs, low pressure is situated close to Iceland, with high
pressure to the SE of the UK. SW'lies are the result, with 850hPa
temperatures ranging from +3C over northern England and Wales to +6C over
southern England. The winds become westerlies for many at T+144, due to a
ridge over Wales, much of England and Ireland. Westerlies continue to affect
most of the UK at T+168, before a trough moves SE'wards on day 8, bringing
northerlies to most areas.

Christmas Day charts:
http://129.13.102.67/wz/pics/Rtavn2881.gif
http://129.13.102.67/wz/pics/Rtavn2882.gif
http://129.13.102.67/wz/pics/Rtavn2883.gif
http://129.13.102.67/wz/pics/Rtavn2884.gif

(Reminder: This continues purely for the sake of interest, as the actual
conditions are unlikely to match those described below)

The chart for Christmas Day shows a very deep low to the SW of Iceland, with
high pressure over the Baltic. Strong SSW'lies cover the UK, bringing 850hPa
temperatures of freezing (NE Scotland) to +3C (southern England).
Precipitation is shown over Scotland and Northern Ireland, as well as over
parts of Wales, northern and eastern England. However, with thicknesses
ranging from 542dam (NE Scotland) to 549dam (SW England), only the highest
peaks would stand a chance of seeing snow.

In summary, the runs today show an unsettled and mild spell midweek, but
after that things become less certain. The Canadian and Japanese runs
develop a northerly outbreak for the end of next weekend, but the GFS is
much less keen (although it does build high pressure over Iceland at that
time). This could well be a damp squib, although on the other hand it may be
the first signs of a more seasonal approach to Christmas. As ever, more runs
are needed.