Here is a summary of the NWP output for noon on Thursday.
Issued 0519, 27th Jan 2008

The end of the working week looks wet and windy, with low pressure nearby.
There's likely to be cold air close to the UK, but the models are less keen
on bringing it over the UK compared with yesterday. It's likely parts of
Scotland at least will see some snow with a much lower risk further south.
Into the weekend both ECM and GFS show mild SW'lies becoming established,
although it should be pointed out that both ECM and GFS were on the mild
site within their ensembles. If the charts are accurate, there'd be a NW/SE
split for the weekend, with the NW seeing more in the way of wind and rain.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
High pressure is located to the south, with WSW'lies across the UK. The
winds become SW'lies tomorrow as a trough develops to the west. The trough
crosses Ireland on Tuesday, bringing SW'lies in advance and WNW'lies after
it passes through. On Wednesday England and Wales lie under a col, with
WSW'lies elsewhere.

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/Rukm1201.gif
http://85.214.49.20/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows strong and zonal jet across the North Atlantic and
the UK. At the 500hPa level there's a zonal flow over the UK as well, with
an upper low to the NE of Iceland and an upper high west of Greenland. ECM
shows a similarly strong zonal flow aloft, with an upper low near Svalbard.
GEM has strong WSW'lies aloft and NGP is the only model to buck the trend,
with a deep trough east of the UK, a ridge over the mid Atlantic and upper
NNW'lies for the UK - in line with what the other models had been showing
for a few days now.
At the surface GFS brings strong WSW'lies over England, Northern Ireland and
Wales, with a col over Scotland. ECM has a deep low to the north and SW'ly
gales over the UK, as is the case with GEM. NGP has a high to the NW, with
lows to the east and WSW. NW'lies affect all areas except the far SW of
England, which lies under a col.

Evolution to T+168
ECM shows a trough to the east on day 6, with coolder NW'lies and WNW'lies
for the UK. By day 7 they're swept away as a low deepens to the NW, bringing
SSW'lies across the UK.
GFS brings westerlies and WNW'lies to most on day 6 as a weak seconary low
moves eastwards over Scotland. To the north of the low, for northern
Scotland, there are some very cold NW'lies. On day 7 low pressure lies to
the NW and a mixture of SW'lies and WSW'lies covers the UK.

Looking further afield
Southerlies and SSW'lies cover the UK on days 8 to 10 with ECM, as a deep
area of low pressure stays in-situ over the mid-Atlantic.
The GFS brings southerlies and SW'lies on day 8 with a trough over Scotland.
There's little change on day 9, but by day 10 pressure builds over France.
Southerlies and SSW'lies persist over the UK.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lon dres)
The ensembles show a 3-day cold spell on the way, followed by a return to
normal temperatures.