?Here is a summary of the NWP output for noon on Monday.
Issued 0508, 4th November 2010

The models are split today. They all agree on a cold start to the week, but
GFS quickly introduces mild, wet and windy conditions as a series of lows
passes eastwards to the north. The European models, meanwhile, have deep
lows closer to the UK and thus retain cooler conditions for longer. Either
way, it's likely to be wet for many!

Analysis and evolution to T+120 via GFS
SW'lies cover the UK with lows to the north and WNW. There are further
SW'lies tomorrow, followed by a trough on Saturday. Ahead of the trough
winds are SW'lies, with NW'lies following behind. WNW'lies cover the UK on
Sunday as a weak ridge moves eastwards.

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.meteociel.fr/modeles/nogapse_cartes.php
The jetstream chart shows a trough to the east and a ridge to the west, with
a northerly flow over Scotland and Northern Ireland. At the 500hPa level
there's a weak ridge over the UK, while MetO shows an upper low to the south
and upper NE'lies for the UK. ECM has an upper low to the WSW, with upper
SE'lies for the UK. GEM is similar to ECM, as is JMA - both have an upper
low to the SW.
At the surface, GFS brings a ridge for Scotland and Northern Ireland, with
NE'lies elsewhere. NE'lies cover the UK with MetO, due to a low over the
English Channel. ECM's low is further west, leading to strong to gale force
ESE'lies over the UK. GEM has a deep low to the SW with easterlies across
the UK, while JMA brings ENE'lies also with a low to the SW.

Evolution to T+168
ECM shows a trough over the UK on day 6, leading to NE'lies. Low pressure
fills over the North Sea on day 7 and this leads to cold but light
northerlies.
GFS has a ridge and light winds for England and Wales on day 6, with SW'lies
elsewhere. SW'lies persist on day 7 as low pressure deepens to the WNW.

Looking further afield
ECM shows WNW'lies on day 8 as a weak ridge approaches from the west,
followed by a trough from a deep low to the NW on day 9. Southerlies affect
areas to the east of the trough, with WSW'lies following. On day 10 there
are twin lows to the NE and NW, with SW'lies across the UK.
Strong SW'lies cover the UK on day 8 with GFS, with a deep low to the north.
A transitory ridge brings westerlies on day 9, ahead of a trough and
SSW'lies on day 10.

Ensemble analysis
http://www.wetterzentrale.de/pics/MT8_London_ens.png
The GEFS still shows a cool spell on the way after the present warmth moves
away.

ECM ensembles
http://www.meteogroup.co.uk/meteo/ep...tt6-london.gif
The ECM ensembles still show an abrupt change to cooler conditions over the
weekend.