Here is a summary of the latest NWP output for noon on Sunday. Issued 0653z,
21/01/04.

ECMWF: http://www.wetterzentrale.de/pics/Recm1201.html
High pressure lies to the west of the UK, with low pressure east of Iceland.
This leads to NW'lies across the UK, strongest over northern Scotland. The
low fills and sinks southwards at T+144 as high pressure builds south of
Iceland; increasingly strong northerlies cover the UK as a result. By T+168
the low lies over the southern North Sea, with strong northerlies and
NNE'lies across the UK.

MetO: http://www.wetterzentrale.de/pics/Rukm1201.html
The Met Office run shows a high to the south of Iceland, with northerlies
for all. The high builds and sinks southwards at T+144, with northerlies
persisting over the UK.

GFS: http://expert.weatheronline.co.uk/
A large high lies to the south of Greenland, with a ridge over Wales and
southern England ahead of a low to the SW. Northerlies and NW'lies are the
result, although by T+120 things become more complicated as the low deepens
and moves eastwards towards Biscay. Northerlies and NE'lies cover Northern
Ireland, Scotland and northern England, with SE'lies or easterlies
elsewhere. Cold air covers the UK, with 850hPa temperatures ranging
from -10C over NW Scotland to -4C over Cornwall. The low deepens over France
at T+144, while the high sinks southwards and declines slightly. Strong to
gale force NNE'lies cover the UK, driving cold air southwards; 850hPa
temperatures are below -12C over Scotland and Northern Ireland. The NNE'lies
continue at T+168 as the low continues to deepen and moves NE'wards over
Germany. The low fills in situ, while the Icelandic High declines in situ on
day 8, with NNE'lies persisting over the UK. The NNE'lies ease somewhat on
day 9, before turning NNW'ly on day 10. By then, a new low is deepening to
the west of Iberia. Cold air remains firmly entrenched over the UK, with
850hPa temperatures from -9C over southern England to -7C over Northern
Ireland.

GEM: http://www.meteocentre.com/models/glb00_120.html
The Canadian run shows NNW'lies and NW'lies, with a deep low west of Norway
and a ridge west of Iceland. 850hPa temperatures vary from -7C over NW
Scotland to -3C over SW England. The sinks southwards over Scotland at
T+144, with light NW'lies and westerlies for all.

JMA: http://www.wetterzentrale.de/pics/Rjma1201.html
A secondary low covers France, while the parent low is west of Norway. A
strong ridge is located south of Greenland, leading to northerlies and
NW'lies across the UK. 850hPa temperatures vary from -7C over northern
Scotland to -4C over southern England. The winds become NNE'lies and NE'lies
at T+144 as high pressure builds to the SE of Iceland. The winds become
NE'lies for all at T+168, as a new low forms over southern France and the
Greenland/Icelandic high continues to build. By day 8 a northerly flow
covers the UK, with high pressure persisting to the west of Iceland.

In summary, the models all agree on a northerly blast for the early part of
next week, yet they still differ on whether it will have much of an easterly
component. The GFS paints a very wintry picture indeed, showing cold air and
a northerly or NE'ly flow over the UK all the way out to T+384. On the other
hand, the Canadian run introduces milder air on day 8 and the Met Office run
shows signs of the block sinking southwards relatively quickly. However,
there is the potential for some quite wintry weather, more especially in the
north and east of the UK. As ever, more runs are needed.