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| December 2000 monthly assessment
issued 2/1/2001 |
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Monthly summaries available for: England
and Wales | Scotland | Northern
Ireland
Homogenous time series based upon selected station data:
CET | England and Wales
rainfall
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| Very mild and very wet first
half with frequent gales and squally showers. Some fog and
frost third week. Much colder with some snow last week. |
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Diary of highlights
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1st - 6th Wet and unsettled but very
mild as complex low pressure to the west brought bands of
rain and showers across the region. The rain was heavy at
times especially in the west, however showers on the 2nd
and 6th were mainly scattered. Eastern counties of England
as usual were the most favoured for sunny periods.
7th - 13th Some more deep depressions passed the
region, in particular on the 7th to 8th, and 12th to 13th.
It continued very mild and very wet especially during the
7th to 8th and 12th. There were frequent squally thundery
showers notably on the 8th, 9th, 10th and 13th, and a funnel
cloud was seen at Scunthorpe. Coastal gales were frequent
with a gust of 81 kn at Mumbles on the 13th.
14th - 18th After some showers there was a chilly spell
with some fog and night frost. Where fog persisted it was
cold or very cold. On the 18th milder weather and rain spread
from the south.
19th - 22nd Mild and mostly wet at first with some hill
and coastal fog, thereafter mainly overcast with temperatures
not far from normal, although the south-east became rather
cold.
23rd - 27th With pressure high over Greenland and low
to the east and south colder weather edged slowly southwards.
Wintry showers fell over northern England during Christmas
day but there was rain further south. By the 26th and 27th
it was cold or very cold everywhere though mainly dry, later
on the 27th a band of rain and snow moved into western districts.
28th - 31st Snow fell widely during the 28th heavy
in places in Wales and the north but only a few cm deep
over southern counties. Snow showers in Wales, the north
and north-east of England on the 29th contained the odd
clap of thunder, earlier in the day -14.4 °C was recorded
at Credenhill/Hereford. Snow depths were about 10 cm in
the Midlands and north Wales to between 8 and 15 cm in north-east
England. Day temperatures stayed below freezing in places
on the 29th and 30th especially in fog. After a mainly cold,
dry, sunny day on the 30th, mild, wet and windy weather
returned with a gust of 87 kn reported from the Lizard lighthouse.
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| Statistical details (using best available
data/estimates): updated 2003 |
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England & Wales Mean Temperature Series ( series
began in 1961 ). The value for the month was 5.3 °C, which
is 1.0 °C above the 1961-1990 average, which is in the above
average category.
England & Wales Rainfall Series ( series began
in 1961 ). The total for the month was 136.6 mm, which is
143 % of the 1961-1990 average, which is in the well above
average category.
England & Wales Sunshine Series ( series began
in 1961 ). The total for the month was 45.5 hours, which
is 102 % of the 1961-1990 average, which is in the close
to average category.
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| Scotland |
| Very mild and wet first half followed by
a white Christmas. |
| Diary of Highlights |
The main feature of December was the huge contrast in
temperature between the first fortnight and the last week.
During the first 12 days of the month a large area of
low pressure in mid-Atlantic directed very mild south-westerly
winds across the country. Temperatures reached 14 °C on
the 1st and 5th and there were frequent bands of rain.
A variation on the general south-westerly theme occurred
on the 8th and 9th as a secondary depression developed
and moved north across Britain. Easterly winds ahead of
this feature ensured that eastern parts bore their share
of the rain.
The main low pressure complex moved gradually east into
Scandinavia so that by the 13th winds over Scotland turned
into the north-west and then the north. It became progressively
colder but drier for a few days.
From the 18th to the 23rd low pressure in the Atlantic
moved slowly south while high pressure formed over Greenland
and the Baltic. Winds over Scotland turned to the south-east,
but mild air with rain spread north on the 19th and 20th
and delayed any significant cooling.
Very cold air circulating around high pressure over Greenland
and Iceland arrived by Christmas Eve, and clear weather
with light snow showers gave a white Christmas to some
places. A southward moving centre of low pressure brought
a substantial snow fall to western and south-western Scotland
on the 28th, with 20 cm of snow reported from Glasgow
and other places. There were snow showers in the north
and east and severe night frosts followed. Another belt
of snow pushed north-east across the country during Hogmanay
evening.
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Statistical details (using
best available data/estimates): updated 2003
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Scotland Mean Temperature Series (
series began in 1961 ). The value for the month was 3.2
°C, which is 0.4 °C above the 1961-1990 average, which is
in the close to average category.
Scotland Rainfall Series ( series began in 1961
). The total for the month was 182.2 mm, which is 117 %
of the 1961-1990 average, which is in the close to average
category.
Scotland Sunshine Series ( series began in 1961
). The total for the month was 29.3 hours, which is 98 %
of the 1961-1990 average, which is in the close to average
category.
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| Northern
Ireland |
| Mild and very wet first three weeks, then
cold and dry with heavy snowfall and severe cold spell during
the last week. |
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Diary of Highlights
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1st - 12th Very mild and
frost-free but also very wet.
13th - 20th Cold with widespread frosts
from 14th to 17th, then milder again and very wet on 19th/20th.
21st - 24th Dry but dull. Little diurnal
range in temperature.
25th - 31st Christmas Day and Boxing Day
were both largely dry and sunny but cold with frost early
and late. Wintry showers mainly confined to the far north.
Persistent heavy snow spread across all areas on the afternoon
of 27th. The following three days were very cold with severe
frost which persisted throughout the day across many areas.
Milder wet weather spread to all areas from dawn on 31st
with rapid melting of snow.
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Statistical details (using
best available data/estimates): updated 2003
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Northern Ireland Mean Temperature Series ( series
began in 1961 ). The value for the month was 4.5 °C, which
is exactly the 1961-1990 average, which is in the close
to average category.
Northern Ireland Rainfall Series ( series began
in 1961 ). The total for the month was 153.3 mm, which is
140 % of the 1961-1990 average, which is in the well above
average category.
Northern Ireland Sunshine Series ( series began
in 1961 ). The total for the month was 30.3 hours, which
is 86 % of the 1961-1990 average, which is in the below
average category.
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Homogeneous series based upon selected station data: updated
2003 |
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Central England Temperature (series begins in 1659).
The mean value for the month was 5.8 °C which is 1.1 °C
above the 1961-90 normal of 4.7 °C and is in the above average
category. Others:- 1999/5.0, 1998/5.5, 1997/5.8, 1994/6.4
°C.
England and Wales Rainfall (series begins in 1766).
The total for the month was 142.2 mm, which is 148 % of
the 1961-90 average and is in the well above average category.
Others:- 1999/142.4, 1998/97.4, 1997/100.8 mm.
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| Note: Diary values are provisional based
on data available at the time. |
