Here is a summary of the latest NWP output for noon on Wednesday. Issued
0607z, 29/01/05.

The runs show NW'lies as being the most likely outcome for the middle of the
week, with high pressure not far from the Azores and low pressure near
Iceland. The GFS then takes the Icelandic Low and moves it quickly SE'wards,
allowing a push of much colder air to affect the UK from the east. For the
past few runs the GFS has forced cold air over the UK one way or the other,
but it invariably happens beyond T+168 - ie at the very far limits of what
I'd consider a reliable timescale. Nonetheless, the GFS ensembles have been
confident of an encroaching cold spell, but until (if) it appears within the
T+144 to T+168 timespan I'll not make too much mention of it.

ECMWF: http://64.246.48.81/pics/Recm1201.gif
A ridge covers England and Wales, bringing NW'lies there and westerlies
elsewhere. Another weak ridge covers the UK at T+144, bringing westerlies
and WNW'lies, followed by westerlies for all at T+168 with high pressure to
the west of Biscay.
Today's ECM "freebie" is the ensemble output, and yesterday's 12z run shows
that a NW'ly flow is the most likely outcome at T+168, although the position
of low pressure varies a fair bit between the 50 members!

MetO: http://www.wetterzentrale.de/pics/Rukm1201.html
The MetO run also shows a ridge over England and Wales, with westerlies and
NW'lies for the UK. The winds strengthen at T+144 as the Azores High moves
westwards and low pressure moves ESE'wards to the NE of Iceland.

GFS: http://expert.weatheronline.co.uk/pslv_frame.htm
NW'lies cover the UK, with the Azores High displaced NE'wards of its
namesake islands. 850hPa temperatures vary from -5C over NW Scotland to -2C
over East Anglia. The winds remain NW'lies at T+144, as the Azores High
sinks southwards and complex low pressure moves ESE'wards in the vicinity of
Iceland. The Azores High ridges strongly northwards at T+168, joining with
the Greenland High. This forces the Icelandic low to move SE'wards and it
deepens over the North Sea to bring strong to gale force northerlies and
NW'lies. Day 8 sees the low become complex over Central Europe, with
NNE'lies for much of the UK. The high to the west topples SSE'wards to the
west of Ireland on day 0, leaving the UK under lighter northerlies. By day
10 winds become southerlies and SE'lies, with low pressure to the west of
Ireland.

GEM: http://www.meteocentre.com/models/glb00_120.html
The Canadian run shows westerlies and WNW'lies for the UK, with high
pressure to the SW. 850hPa temperatures range from -1C over Kent to +3C over
the Highlands. A trough crosses the UK in association with a low to the
north at T+144, this leads to westerlies for all. High pressure builds to
the west as another trough crosses the UK on day 7, with northerlies moving
eastwards across the UK.

GME/DWD:
http://www.wetter.com/home/img/sat/g...270000_120.gif
As with several of the other runs, a ridge covers the UK and this leads to
NW'lies and westerlies. The ridge sinks SE'wards at T+144, allowing
westerlies to affect the UK, followed by WNW'lies on day 7.

JMA: http://www.wetterzentrale.de/pics/Rjma1201.html
The Japanese run shows NNW'lies for much of the UK, with the Azores High to
the SW. The winds become westerlies for all at T+144 as complex low pressure
moves eastwards to the north of Iceland. Westerlies continue to affect the
UK on day 7, before a trough brings westerlies and NW'lies on day 8.

NOGAPS: http://129.13.102.67/wz/pics/ngp10.prp.120.europeg.gif
Unavailable today.

GM CPTEC: http://www.cptec.inpe.br/prevnum/Global126_sx6_Gl.shtml
Unavailable today.

KMA: http://www.kma.go.kr/kma03/gif/g21nh_smsr_120.gif
The UK lies under NW'lies, with high pressure to the SW.