Today's model interpretation (3/02/12)

[Darren Prescott]

Here is a summary of the NWP output for noon on Tuesday.
Issued 0500, 3/02/12

The middle of the week will see another trough moving in from the west, but
unlike Sunday's trough this one is likely to dissipate before it reaches the
east. High pressure will still lie to the east and as a result eastern areas
are likely to remain colder than average throughout the week. Further west
ECM shows slightly milder weather, while GFS ends up bringing cold east or
ENE'ly winds across the majority of the UK by the end of the week.

Analysis and evolution to T+120 via GFS
A large ridge covers the UK, with light winds for all. Tomorrow a col covers
much of England and Wales as southerlies pick up over Scotland and Northern
Ireland. A trough moves eastwards and on Sunday it disrupts over the UK,
with SSE'lies ahead of it and westerlies following behind. By Monday there's
a weak trough over the Midlands, with SSW'lies in advance and milder
WSW'lies following behind.

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 ridge over Ireland with the jet heading
southwards over England and the North Sea. At the 500hPa level there's also
a ridge over Ireland, with northerlies aloft over much of the UK. MetO is
similar, as is ECM. GEM has an upper ridge from the NE over the UK, while
JMA shows SW'lies aloft due to an upper ridge over the SE.
At the surface GFS has southerlies and SSE'lies with a ridge to the east.
MetO also shows southerlies and SSE'lies, as does ECM. GEM is again similar,
while JMA has milder SSW'lies for all.

Evolution to day 7
ECM brings a trough over Ireland on day 6 with southerlies and SSE'lies
persisting for most of the UK. There are further SSE'lies and southerlies on
day 7.
Southerlies cover much of the UK on day 6 with GFS, with a trough over
Northern Ireland and a ridge over East Anglia. On day 7 high pressure builds
strongly over southern Scandinavia, resulting in NE'lies from southern
Scotland southwards, with southerlies further north.

Looking further afield
A weak trough covers the UK on day 8 with ECM, leading to light winds. A
ridge moves eastwards on day 9, with westerlies north of the Midlands and
with northerlies to the south. On day 10 there are westerlies for all as the
ridge moves SW'wards.
GFS shows moderate ENE'lies for all areas except Scotland on day 8, with a
ridge over Scotland bringing light winds there. On day 9 the Scottish ridge
declines, with easterlies for most. Easterlies persist into day 10 as high
pressure recentres to the NW.

Ensemble analysis
http://www.meteociel.com/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres
The GEFS shows cold weather continuing for at least the next week.

ECM ensembles
http://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif
ECM also shows a generally cold outlook, with only a moderate (30%) chance
of a milder spell from the 8th.