Here is a summary of the NWP output for noon on Friday.
Issued 0518, 18th January 2010.

A ridge will move across the UK during the weekend, bringing generally
settled weather with overnight frosts. There may be some rain in the east at
first.

Analysis and evolution to T+120 via GFS
SW'lies cover the UK, with a high over France. Tomorrow the winds become
SE'lies and SSE'lies as a trough disrupts to the SW. There are further
SE'lies on Wednesday, followed by a mixture of southerlies and SE'lies on
Thursday as the trough moves eastwards.

T+120 synopsis
http://91.121.93.17/pics/Rtavn12015.png /
http://91.121.93.17/pics/Rtavn1201.png
http://91.121.93.17/pics/Rukm1201.gif
http://91.121.93.17/pics/Recm1201.gif /
http://www.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a large ridge to the west, with the UK under a
trough. At the 500hPa level there's a weak trough, with upper westerlies for
the UK. ECM has upper SW'lies with a trough to the NW and a ridge to the SW,
as is the case with GEM. MetO shows upper SW'lies too, as does JMA.
At the surface, GFS brings westerlies with a trough to the east. ECM has a
trough to the east too, with WSW'lies. GEM brings a weak ridge with light
winds for all areas except Scotland and Northern Ireland, which lie under
SW'lies. MetO has WSW'lies for all with a low over Iceland, while JMA brings
SSW'lies and a trough to the west.

Evolution to T+168
ECM shows a ridge on day 6 with westerlies. On day 7 the ridge persists over
England and Wales, with southerlies elsewhere.
GFS brings NW'lies on day 6 with a ridge to the west. On day 7 a col covers
the UK.

Looking further afield
ECM shows southerlies ahead of a trough on day 8, followed by a trough over
Scotland on day 9. Ahead of the trough winds are SE'lies, with WSW'lies
following behind. Day 10 sees easterlies and NW'lies as a trough sinks
southwards over the UK.
GFS has southerlies on day 8 as a ridge moves eastwards, followed by further
southerlies on day 9. A col covers the UK on day 10.

Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ille=Lond res)
The GFS ensembles show a generally average outlook.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
ECM shows a couple of cold days later this week, with an otherwise near
normal outlook.