The general pressure situation for the period 11th to 20th January 2004
is marked by an area of LP from Iceland down to Ireland. A weak
trough continues further across France SE'wards to the
Mediterranean. A large HP covers the Balkans, E Germany, Poland, the
Baltic and Scandinavia up to E Greenland. For Britain this means wet
conditions for the W of the country and dryer conditions for the NE and
E of the country. It also means a change in the wind direction which
now comes from the S or SE bringing generally slightly warm air from
the S and sometimes cooler air from the SE, depending on the source.

The general run of weather throughout the period starts with LP in the
NW which moves E'wards. At the same time, HP over most of central
Europe drifts S'wards towards the Balkans. After the middle of the
period, a belt of LP from about Scotland to N Scandinavia drifts
SE'wards in its southern part so that on about 17th, an upper air
trough lies over SW France. As the trough and associated LP drifts
NE'wards towards N Germany, HP builds up from the SW of Britain and
joins up with the large area of HP over the continent. By the end of
the period, HP covers much of Europe . Chances of a Scandinavian HP
developing are 14th and 15th, (a stable HP centre not fully
established) - 17th, 18th, 19th and 20th (very good chance of stable
HP centre).

London's general temperature looks to fall throughout the period - to
be lowest on 21st January according to the forecast temperature curve.
Dips are expected to occur near 12th, 14th,17th and 21st. Peaks on the
curve are expected on 13th 15th and 20th.

On 11th January LP covers NW and W Scotland and Wales. Winds are W or
NW over the country, but may be S down the E coast. The southern part
of the LP is expected to swing across N England into the North Sea
as HP sweeps over Biscay and Spain to build up over the near
continent. Scotland will have its share of rain but the S and SE of the
country will be less rainy.

On 12th January a medium sized LP lies to the NW of Britain with a
trough E'wards towards the Norwegian coast. A secondary LP out in the
Atlantic moves in the direction of SW Britain. A large area of HP
covers central Europe and the Mediterranean. Winds are generally from
the W. Once again Scotland has the most rain, while central and SE
areas are dryer.

On 13th January a large LP lies near Iceland bringing W to SW winds over
Britain. A small secondary LP near the Channel is expected to move
into the North Sea. Over S Finland, Poland and parts of Russia, a large
HP has built up which is expected to be pushed southwards by a LP
further N. SW'erly winds flow over the country brings much rain over
the N'ern half of Britain.

On 14th January a complex area of LP extends from near the Iceland
area down to S England. Small waves drift along in the W airstream
towards S Britain. An area of HP to NW Norway has a ridge S'wards
towards the North Sea. During the morning, the Azores HP builds up to
the SW of Britain and moves E'wards towards the Channel. Rain showers
along the S coast move E and dry weather lies over the N half of the
country. Variable winds at first turning W or NW later as fair
weather. enters the country from the SW.

On 15th January HP has built up and covers the E and SE parts of the
country and the North Sea. A LP lies near Iceland with a secondary on
its S flank. The secondary is expected to move into the SW of England
later Winds will be light in the E and SE but S winds occur in the W.
Weather will be dry in most places at first with some frost and fog
early, but rain will spread across S areas later.

On 16th January a LP lies to the N of Scotland and a small Atlantic LP
is moving E'wards towards NW Ireland. A small ridge from the Azores HP
covers Ireland, Wales and England, and this moves E'wards into Central
Europe, intensifying all the time. N Spain and SW France has the
secondary LP which was in the Channel yesterday This Spanish
secondary LP is drifting NE and filling. Winds will be light and
variable at first but will then come from the SW later. The weather
will be mostly fine and dry over most parts of the country, and some
areas will have early frost.

On 17th January a belt of LP extends from N Ireland to N Scandinavia
The LP over Ireland swings in an E or SE direction, and in so doing,
forms a new LP in the Channel area round about noon. A large HP lies
over the W Mediterranean, Italy France, Germany up to Poland, and this
is moving NE'wards. Winds mainly SW but becoming variable or E'ly in
the S later. Rain over N Scotland and rain along the S coast later,
but dryer in SE of the country.

On 18th January a LP area near Iceland has a trough towards N
Scotland. A small LP lies in the Channel with a trough down to Spain
and moves NE and fills. The Azores HP has a ridge to the W of Ireland,
and this is moving E'wards A large HP near Finland has a ridge W'wards
along the S Baltic to SW Norway. Winds are variable but could be E in
the S half of Britain. In Scotland the weather will be mostly dry
with frost early and late, but in the S, there could be much rain.

On 19th January LP to the WNW of Scotland has a trough E'wards to SW
Norway. A HP area comes into SW Britain , intensifies and extends NE
towards E Scotland. Another HP area over central Europe moves NE to
join up with the large HP area over Finland and N Russia. Winds will
be light and variable and the weather will be mostly dry with frost and
fog early and late in most areas.

On 20th January a HP area covering the E part of Britain moves
quickly E and SE as a LP SW of Iceland and its secondary LP, rush
across the country from the W. Winds are light and variable at first
but turn SW from the W. The weather will be mostly dry at first with
frost and fog in many places, but rain spreads in from the W later.

The Scandinavian HP seems to be the interesting feature of this
period. Once the HP over Scandinavia has developed it is sometimes
very difficult to shift - especially if it's a solid cold HP. That would
mean that the LP's activity would be confined to the HP periphery
resulting in a distorted view of the weather situation.

Cheers, Keith .