Here is a summary of the NWP output for 12z on Friday.
Issued 0541z, 18/12/06

For England and Wales, the next week will see very settled conditions with
frost and fog for many areas. A large anticyclone will dominate the scene
until next weekend at least. Northern Ireland and especially Scotland will
probably escape much of the fog and probably the frost too as winds pick up
from the west or southwest.

Analysis and evolution to T+120 via GFS
http://85.214.49.20/pics/Rtavn001.png
http://85.214.49.20/pics/avnpanel1.gif
A shallow low lies to the west of Scotland with a ridge over England and
Wales. Winds are light across the UK, as will be the case tomorrow as high
pressure builds strongly. The high builds again on Wednesday, but sinks
southwards slightly and this leads to westerlies picking up across Scotland.
By Thursday the high builds over England and Wales with SW'lies elsewhere.

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.jpg /
http://85.214.49.20/pics/Rukm1201.jpg
http://85.214.49.20/pics/Recm1201.jpg /
http://85.214.49.20/pics/Rngp1201.jpg
The jetstream chart, as yesterday, shows a marked shortwave pattern to the
west, north and NE of the UK as the jet heads NE'wards over the North
Atlantic, Scandinavia and beyond. At the 500hPa level the main feature is a
large upper high centred over the UK, with lows over Greenland and to the
north of Scandinavia. MetO shows an even stronger upper high over England
and Wales and ECM is very similar. JMA shows a large ridge across the UK and
across to Denmark, while NGP centres the upper high to the SW instead. GEM
also shows a ridge from the SW.
At the surface GFS brings light winds across all areas except Scotland,
which lies under WSW'lies on the periphery of the high. Much the same is
true with MetO, although with a centre over the North Sea there's a slight
easterly drift over southern England. ECM also shows a very similar picture
with a large, strong high over England, Wales and Northern Ireland. JMA has
a ridge over England and Wales with moderate to strong SW'lies elsewhere,
while NGP keeps the high over the English Channel instead with SW'lies for
all. GEM is similar to NGP with SW'lies for all.

Evolution to T+168
ECM shows the high moving slowly eastwards as the upper high also moves
eastwards. On day 6 southerlies cover Northern Ireland with SW'lies for
Scotland as the high builds over East Anglia. By day 7 the high moves over
the Low Countries, with a mixture of SE'lies, southerlies and SW'lies for
the UK.
GFS also shows the high heading eastwards. On day 6 it lies over the North
Sea, bringing easterlies across England and Wales with southerlies or
SSW'lies elsewhere. A trough disrupts far to the west on day 7, with the
high moving over Germany. SE'lies and ESE'lies cover England and Wales, with
southerlies elsewhere.

Looking further afield
Beyond T+168, ECM shows southerlies and SSW'lies for the UK on day 8 as a
front moves in from the west. The front doesn't make much progress though
and disrupts as it crosses Ireland, with a trough over the English Channel.
Southerlies still cover much of the UK as a result. By day 10 the UK lies
under southerlies and SSW'lies as the trough loses its identity.
GFS also brings southerlies over the UK on day 8 with a trough to the west.
Unlike the ECM though the trough has no problems moving swiftly eastwards
and by day 9 the UK lies under WSW'lies. Day 10 sees a mixture of SW'lies
and southerlies as a weak ridge crosses the UK.

Ensemble analysis
(http://expert.weatheronline.co.uk/da...ia/ensdia.html - last
night's 18z)
After two more days of cool conditions aloft, temperatures at 500hPa look to
rise markedly for a prolonged period.

"Darren Prescott" none@no,dns wrote in message
...
Here is a summary of the NWP output for 12z on Friday.
Issued 0541z, 18/12/06

For England and Wales, the next week will see very settled conditions with
frost and fog for many areas. A large anticyclone will dominate the scene
until next weekend at least. Northern Ireland and especially Scotland will
probably escape much of the fog and probably the frost too as winds pick
up from the west or southwest.

Recent runs have taken the central pressure of the high to anything between
1043 and 1048 mbar over southern Britain around the 23rd. 1043 is, of
course, not unusual, but 1048 is. Worth keeping an eye on.

Philip

Philip Eden wrote:

Recent runs have taken the central pressure of the high to anything between
1043 and 1048 mbar over southern Britain around the 23rd. 1043 is, of
course, not unusual, but 1048 is. Worth keeping an eye on.

Philip



What will be interesting is how cold will it get, assuming we get clear
radiation nights and not a lot of cloud, even now the effect is quite
remarkable with mist forming in the fields around my area of
Southend-on-Sea.
Even though the runs slowly migrate this high to our east / southeast it
may have more staying power than is expected. Northern Scandinavia has
also seen some very low temperatures -20°c and lower has not been
uncommon I notice. It may not be anything significant until the new year
but I have a sneaky feeling about this winter ;-) Ho ho ho.
--
Keith (Southend)
http://www.southendweather.net
e-mail: kreh at southendweather dot net