Here is a summary of the NWP output for 12z on Sunday.
Issued 0519z, 31st January 2007.

Although next week will start on a settled note it won't last for long. Low
pressure, driven by a very strong jet, will approach the UK from the west.
Although very high ground might be cold enough for snow for the majority
it's likely to just bring plenty of rain, along with the chance of some
strong winds depending on the track of the lows.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
WSW'lies cover the UK, with high pressure to the SW and a trough to the
north. Pressure builds to the SW tomorrow, leading to westerlies and
WSW'lies for the UK. WSW'lies affect all areas on Friday, followed by light
winds as the Azores High moves over the UK on Saturday.

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/Rjma1201.gif /
http://85.214.49.20/pics/Rukm1201.gif
http://85.214.49.20/pics/Recm1201.gif /
http://85.214.49.20/pics/Rngp1201.gif
The jetstream chart shows weak ridge over the UK and an "off the scale" jet
heading ENE'wards along 50N to the west. At the 500hPa level there's a ridge
to the west and an upper high over France. ECM also shows an upper high over
France, while MetO instead has a stronger ridge to the west and an upper
trough over Scotland. JMA and NGP both have an upper high close to or over
the UK, while GEM has a ridge to the west instead as per MetO.
At the surface GFS has high pressure bringing light winds to many areas,
with northern Scotland under westerlies. ECM brings westerlies for all with
high pressure over the English Channel, while MetO shows a trough over
northern Scotland and westerlies for all. JMA also shows westerlies for
Scotland and Northern Ireland, with high pressure elsewhere. NGP brings
light winds for all with a high over Wales and GEM shows a NW'ly flow
courtesy of a ridge to the west.

Evolution to T+168
ECM shows a col over the UK on day 6. On day 7 low pressure attempts to move
in from the west, leading to SE'lies for all.
GFS is more progressive again. SW'lies cover the UK on day 6 as the high
collapses over the UK. By day 7 SSW'lies affect all areas ahead of a trough
to the west.

Looking further afield
ECM shows low pressure over Ireland on day 8, leading to a mixture of
SE'lies and ESE'lies for the UK. SW'lies cover the UK on day 9 as the low
moves northwards and by day 10 SW'lies persist for all with low pressure to
the NW.
GFS brings raging zonality to the UK. Day 8 sees WSW'lies with a low to the
north, followed by SW'ly gales on day 9 as low pressure deepens near
Iceland. By day 10 the UK lies under strong to gale force WSW'lies as low
pressure moves eastwards to the north.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
The ensembles show good agreement of a much wetter period approaching from
the 6th.