?Here is a summary of the NWP output for noon on New Year's Day.
Issued 0515, 28th December 2010.

The weekend will see NW'lies over the UK, with high pressure to the west.
Most areas will have settled conditions, with patchy frost by night should
skies clear. Into next week there's little change, with high pressure
remaining in control.

Analysis and evolution to T+120 via GFS
A mixture of southerlies and SE'lies covers the UK, with a low to the west.
There's little change tomorrow, but on Thursday pressure builds over
Scotland and England, with SE'lies elsewhere. High pressure builds across
the UK on New Year's Eve, bringing light winds.

T+120 synopsis
http://www.wetterzentrale.de/wz/pics/Rtavn12014.png
http://www.wetterzentrale.de/wz/pics/Rtavn1201.png
http://www.wetterzentrale.de/wz/pics/Rukm1201.gif
http://www.wetterzentrale.de/wz/pics/Recm1201.gif
http://www.wetterzentrale.de/wz/pics/Rjma1201.gif
The jetstream chart shows a meridonal pattern over the north Atlantic, with
the UK under a ridge on the warm side of the jet. At the 500hPa level the
flow is northerly, with a ridge to the west. MetO has a NW'ly flow with a
ridge to the west and ECM brings upper NW'lies with a flatter pattern to the
west. GEM has an upper high over the UK and JMA brings an upper high over
the Celtic Sea, with NW'lies for much of the UK.
At the surface, GFS brings a high to the NW and northerlies for most. SW
England and Northern Ireland lie under NE'lies, however. MetO brings
northerlies and NW'lies as a trough moves southwards, while ECM has
anticyclonic NW'lies across the UK. GEM has a ridge and light winds over the
UK and JMA shows a high to the west with NW'lies for all.

Evolution to T+168
ECM shows further westerlies and WNW'lies on day 6, with pressure remaining
high to the SW. The westerlies strengthen on day 7 as the high builds to the
SW.
A high covers the Celtic Sea on day 6 with GFS, leading to NW'lies and
WNW'lies. On day 7 the high declines, with WNW'lies for all.

Looking further afield
Day 8 with ECM shows WNW'lies and NW'lies with the Azores High remaining to
the SW. On day 9 the Azores High ridges northwards, introducing NNW'lies for
the UK. The high declines on day 10, with a mixture of northerlies and
NW'lies over the UK.
NW'lies cover the UK on day 8 with GFS, due to a high to the west. The high
declines and moves SE'wards on days 9 and 10, with westerlies and NW'lies
persisting for the UK.

Ensemble analysis
http://www.meteociel.com/cartes_obs/...&ville=Londres
The 0z GEFS shows a cold spell on the way, with temperatures falling below
average by Friday.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
ECM also shows temperatures falling at the end of the week, with the
operational a marked mild outlier on days 7 and 8.