Cyclonic episodes from 1st-8th and 29th-31st contributed most
of December's rain ... otherwise the month was predominantly
anticyclonic although the centre of high pressure was not often
located over the British Isles. Locally on the south coast there
were 21 consecutive days with no significant rain (from the
6th-26th). The anticyclone of the 11th-12th was intense, pressure
reaching 1046.9 mbar in NW Ireland which is probably the
highest in Dec in the UK since 1980.

More available:
Charts: http://www.climate-uk.com/monpre/0512.htm
The Monthly Review will appear later today or tomorrow
at: http://www.climate-uk.com/monthly/0512.htm
Graphs: http://www.climate-uk.com/graphs/0512.htm and
http://www.climate-uk.com/graphs/200512.htm
Not The Long Range Forecast will be uploaded on Jan 3 to
http://www.climate-uk.com/page4.html

The mean sea-level chart shows a markedly diffluent W-ly
flow over the British Isles. The Icelandic Low (999 mbar) is
displaced to the west of Greenland, although a significant
weakness extends eastwards towards Iceland, thence north-
eastwards towards Svalbard. There are further weak lows,
indicative of favoured locations for depressions for part of
the month, near Stockholm (1012) and Naples (1015).
The Azores high (1023) is located somewhat to the
northeast of its usual position.

The sea-level pressure anomaly field is quite unusual in
having above-normal pressure over such a large area -
practically the whole of the Atlantic north of 35 degN
together with all of western and northern Europe. The main
anomaly centres a
+12mbar near Novaya Zemlya
+7mbar in the Norwegian Sea
+7mbar west of Ireland at 51N 23W
-6mbar over Quebec
-2mar in the northern Adriatic.
Over the British Isles pressure anomaly ranges from +2mbar in
Kent to +5.5mbar in Shetland and the W.Isles. The anomalous
flow over the UK is NE-ly.

CET (after Manley) 4.6°C (-0.5 degC wrt 1971-2000)
CET (after Hadley) 4.7°C (-0.4 degC)
making it the coldest December since 2001, and the
coldest Nov/Dec since 1996
E&W Rain: 73.9mm ( 73% of 1971-2000 mean)
not quite as dry as Dec 2004
E&W Sunshine: 64.5 hr (135% of 1971-2000 mean)
in fourth place behind 1886, 1962 and 2001, while
Nov/Dec was the sunniest on record.

CScotT: 4.9°C (+0.4 degC)
ScotRain: 71.3mm ( 67%)
ScotSun: 33.7 hr ( 98%)

NIT: 6.3°C (+0.1 degC)
NI Rain: 89.8mm ( 96%)
NI Sun: 36.4 hr ( 97%)

Rainfall totals ranged from 195mm at Cardinham (Cornwall)
to 23mm at Scampton and Holbeach (both Lincs). Percentages
ranged from 125 at Cardinham to 33 at Shap (Cumbria).

Sunshine totals ranged from 103.4hr at Eastbourne (Sussex)
to 12.5 hr (KZ sensor), 14.9 hr (CS recorder) at Lerwick
(Shetland). Percentages ranged from 188 at Church Fenton
(N.Yorks) and Odiham (Hants) to 65 at Kirkwall (Orkney).
One wonders just how sunny this December would have been
had it occurred during, say, the 1920s or 30s when
particulate pollution was so much higher.

(c) Philip Eden

E&W Rain: 73.9mm ( 73% of 1971-2000 mean)
not quite as dry as Dec 2004

Am surprised, Dec 2005 seemed significantly drier than 2004 in the
south, and given how westerly Dec 2004 was I'd imagine it was even more
the case in the north. I guess the two short-lived lows at each end of
the month made it wetter?

Nick

wrote in message
oups.com...
E&W Rain: 73.9mm ( 73% of 1971-2000 mean)
not quite as dry as Dec 2004

Am surprised, Dec 2005 seemed significantly drier than 2004 in the
south, and given how westerly Dec 2004 was I'd imagine it was even more
the case in the north. I guess the two short-lived lows at each end of
the month made it wetter?

Nick


Hi Nick,

Dec 2005 was indeed wetter than Dec 2004 in Romsey by
almost 20mm, but in view of there being fewer wet days in
Dec 2005 (8 as opposed to 9), it may have been perceived
as being drier than Dec 2004.

Out of the 76mm measured last month, only 1mm fell in the
21 days from the 8th to the 28th inclusive.

Hope this helps,

Nigel.

wrote in message
oups.com...
E&W Rain: 73.9mm ( 73% of 1971-2000 mean)
not quite as dry as Dec 2004

Am surprised, Dec 2005 seemed significantly drier than 2004 in the
south, and given how westerly Dec 2004 was I'd imagine it was even more
the case in the north. I guess the two short-lived lows at each end of
the month made it wetter?

I know the site isn't the easiest to navigate, but it would
take only a modicum of exploring to compare
http://www.climate-uk.com/graphs/0512.htm
with
http://www.climate-uk.com/graphs/0412.htm

Philip