PITSFORD HALL WEATHER STATION
NORTHAMPTON UNITED KINGDOM

MONTHLY WEATHER REPORT - JANUARY 2003

Headline: Following a wet start, a protracted cold snap 
leading into an unseasonably mild spell in the latter half, 
then ending cold again with snow showers.

January opened on a very unsettled theme with a complex area 
of low pressure with at least five discrete centres and 
associated frontal systems straddling the British Isles. The 
system continued to deepen on the 1st and 2nd before high 
pressure became established west of Ireland. Both the 1st 
and 2nd were particularly wet days with totals reaching 13.4mm 
and 12.1mm respectively. Despite the low pressure winds 
remained comparatively gentle.

With high pressure gaining ground and remaining generally 
centred to the west of Britain over the following few days, 
a run of cold northerly or north-easterly winds brought a 
sharp cold snap across the county. Daytime maxima fell markedly, 
reaching only 0.1C on the 7th and 0.9C on the 8th with a bitterly 
cold night to follow with lows of -4.2C.  A frontal system tied 
into low pressure north of Scandinavia also brought snow 
overnight with accumulations to 2.5cm at Pitsford Hall.

High pressure then slipped away southwards from the 12th onwards 
allowing a run of mild south or south-westerly winds bringing to 
an end the cold spell. Temperatures climbed handsomely over the 
next few days reaching a high of 10C on the 15th with overnight 
temperatures holding up at 7.0C.  By about the 15th Britain had 
become caught in between a fairly intense low moving to the 
north of Scotland and high pressure firm over continental Europe. 
This brought a succession of fairly windy days, gusts to 39mph on 
the 16th, although it remained dry.

Britain became increasingly under the influence of a succession of 
Atlantic lows from the 18th onwards. Active fronts gave rise to 
substantial rainfall totals with 16.0mm being recorded on the 18th 
and a further 11.8mm being noted for the 20th. However, on the 23rd 
a ridge of high pressure gained control over the south bringing a 
brief dry and sunny spell (6.1hrs) before ceding to an Atlantic air 
flow bringing unseasonably mild conditions and showery spells. 
By the 27th daytime maxima had climbed to a noticeably warm 13.5C.

However, the month was to close in a rather more wintry fashion 
as the UK became sandwiched between low pressure over Scandinavia 
and an extension of high pressure northwards from the Azores. 
This forced a run of very cold northerly winds across the UK 
bringing temperatures tumbling and snow showers to the 28th and 
30th. 

Overall January was about average temperature-wise with rainfall 
slightly up on the average.


STATISTICAL SUMMARY - JANUARY 2003


Air Temperatures				
The Highest Maximum:			13.5C	on	27th
The Lowest Maximum:			0.1C	on	7th
The Highest Minimum:			7.0C	on	15th
The Lowest Minimum:			-5.2C	on	12th
The Mean Maximum:			6.9C		
The Mean Minimum:			1.2C		
The Overall Mean:			4.1C		
Difference from the Monthly Mean:	-0.1C		
				
Relative Humidity:				
Highest Relative Humidity (at 0900):	98.6%	on	2nd
Lowest Relative Humidity (at 0900):	80.5%	on	29th
Mean Relative Humidity (at 0900):	92.2%		
				
Dew Point:				
The Highest Dew Point (at 0900):	8.1C	on	27th
The Lowest Dew Point (at 0900):		-3.8C	on	5th
The Mean Dew Point (at 0900):		2.6C		
				
Rainfall:				
Total:					70.0mm		
Difference from the Monthly Mean:	133.8%		
Duration:				49.4hrs		
Highest 24 hour fall (from 0900):	16.0mm	on	18th
Rain Days (>/=0.2mm):			16			
Wet Days (>/=1.0mm):			9			
				
Sunshine:				
Total Duration of Bright Sunshine:	71.1hrs		
Sunniest day:				6.1hrs	on	5th
Sunless days:				8
Cloud cover (mean at 0900):		6.1oktas (76.3%)	
				
Pressure (reduced to sea level):				
The Highest Pressure:			1036.9mb on	11th
The Lowest Pressure:			972.4mb	on	22nd
Mean Pressure (recorded at 0900):	1013.8	mb		
				
Winds				
Run of wind (mean over 24 hrs):		169.7miles		
Mean daily wind speed:			9.2mph		
Run of wind (to date):			5261.7miles		
Highest Maximum Gust:			65mph	on	30th
Other gusts 50mph or more:		55mph 	on	28th
					50mph	on 	29th
Highest wind strength (at 0900):	39.2mph	on	29th
Mean wind strength (at 0900):		11.6	mph		
				
Winds from the Following Directions:	

N 7 NE 2 E 1 SE 0 S 8 SW 4 W 1 NW 8 Calm 0		
				
Ground Temperatures:			 	
Lowest Grass Minimum:			-7.2C	on	31st
Mean Grass Minimum:			-1.1C		
Lowest Concrete Minimum:		-5.9C	on	10th
Mean Concrete Minimum:			-0.1C		
Lowest Bare Earth Minimum:		-4.2C	on	6th
Mean Bare Earth Minimum:		0.6C		
				
Soil/Earth Temperatures:		 		
Surface mean:				3.4C		
5cm mean:				3.0C		
10cm mean:				3.5C		
20cm mean:				4.2C		
30cm mean:				4.5C		
40cm mean:				4.6C		
50cm mean:				5.1C		
100cm mean:				5.8C		
				
				
Days with:				
Thunder:				0			
Hail less than 0.5mm:			1			
Hail greater than/equal to 0.5mm:	0			
Snow or snow & rain:			4	
Snow lying:				2: 9th & 30th		
Fog					0	
Air Frost:				10
Duration of Air Frost:			122hrs
Ground Frost:				16