Monthly Weather Review - Pitsford Hall

Headline: Wet and windy at times, but with a protracted dry and cool spell mid-month with some bitterly raw days.

December began with a fairly complex low dominating the scene with a number of distinct centres around the coast of Scotland. This system drove some strong winds across the county and spells of rain, although daytime temperatures were reasonably mild for the time of year. This low slowly moved eastwards on the 3rd allowing a ridge of high pressure to build up from the south. However, this ridge was very transient and the county soon came under influence of a new area of low pressure which drove frontal systems eastwards on the 4th and 5th. Despite a brief respite from the wind on the 3rd, wind speeds again increased but coming from a mild southerly direction they maintained daytime temperatures which peaked at 14.9C on the 6th.

The 6th turned out to be a very unsettled day across the county. The already complex low was further enhanced by another distinct centre which had worked quickly across the Atlantic. Winds gusted to 59mph in the early morning at Pitsford with some 5.1mm of rain falling in just over 3 hours. Despite the strong winds there were no reports of any serious structural damage, although roads were littered with fallen branches.

In the cold air mass which followed the storms temperatures fell significantly the next day, although once more pressure built only momentarily to be replaced by a succession of very active fronts tied into a deep low. These fronts saw 6.7mm of rain falling on the 8th followed by a further 4.8mm on the 9th. Winds once more increased peaking at 51mph on the 9th. The low tracked across northern Britain and then steered south-eastwards towards Denmark on the 10th where it encouraged a colder northerly airflow across the county.

The low over Denmark quickly filled as a more long-lasting area of high pressure established itself over the UK, first as a ridge on the 11th but then becoming quite a large anticyclone extending from Iberia through to Scandinavia. This high resulted in a protracted period of settled weather throughout mid-December. Some good spells of sunshine were recorded at times but with a mainly easterly breeze temperatures were depressed and clear skies which followed overnight saw several frosts, particularly overnight on the 12th through to the 13th when air minima fell to -2.2C and the temperatures the following day struggled to reach 3C. From the 14th the high had started a spell of ‘anticyclonic gloom’ with some particularly grey and misty mornings which were slow to clear. The lack of sunshine during the day and some hard overnight frosts resulted in two very cold days on the 20th and 21st when temperatures rose to just 1.6C and 1.4C respectively. However, by the 22nd milder air was being introduced from the Atlantic, but with it came outbreaks of rain and some fairly extensive fog.

Christmas Eve across the county was dominated by a strong south-westerly breeze which resulted in a mild day followed by showers overnight into Christmas Day which stayed reasonably mild. Both Christmas Eve and Christmas Day remained overcast, although some sunshine broke through on Boxing Day. Highs on Boxing Day reached 10.4C but fell sharply overnight although averting an air frost.

As December came to close it continued reasonably mild, although skies were generally grey with sunshine in very short supply. An active weather system introduced rain and some strong winds on the 28th with gusts reaching 43mph at Pitsford. The wind remained strong into the 29th, but by New Year’s Eve an area of high pressure was beginning to exert an influence across the south-east bringing the month and the year to a settled end in contrast to the strong winds of last New Year’s Eve.

Air Temperatures    
The Highest Maximum:   14.9C on 6th
The Lowest Maximum:   1.4C on 21st
The Highest Minimum:   9.2C on 28th
The Lowest Minimum:   -5.2C on 20th
The Mean Maximum:   7.5C  
The Mean Minimum:   2.0C  
The Overall Mean:   4.8C  
Difference from the Monthly Mean: -0.7C  
    
Black Bulb    
Maximum (at 0900):   12.1C on 5th
Mean (at 0900):    3.9C  
    
Relative Humidity:    
Highest Relative Humidity (at 0900): 100.0% on 21st & 23rd
Lowest Relative Humidity (at 0900): 76.2% on 3rd
Mean Relative Humidity (at 0900): 90.6%  
    
Dew Point:    
The Highest Dew Point (0900):  11.7C on 5th
The Lowest Dew Point (at 0900): -4.5C on 20th
The Mean Dew Point (at 0900):  2.8C  
    
Rainfall:    
Total:     38.5mm  
Difference from the Monthly Mean: 61.2%  
Duration:    37.8hrs  
Highest 24 hour fall (0900 to 0900): 6.7mm on 8th
Rain Days (>/=0.2mm):   13   
Wet Days (>/=1.0mm):   9   
    
Sunshine:    
Total Duration of Bright Sunshine: 40.5hrs  
Sunniest day:    6.2hrs on 29th
No. of days without sunshine:  15   
Difference from the Monthly Mean: 70.4%  
Cloud cover (mean at 0900):  6.1oktas (76.3 %)
    
Pressure (reduced to sea level):    
The Highest Pressure:   1041.6mb on 13th & 14th
The Lowest Pressure:   979.0mb on 9th
Mean Pressure (recorded at 0900): 1019.9mb  
    
Winds    
Run of wind (mean over 24 hrs): 171.5miles  
Mean daily wind speed:   9.3mph  
Run of wind (cumulative):  5316.0miles  
Highest Maximum Gust:   59mph on 6th
No. of gusts of 50mph or more:  1   
Highest wind strength (at 0900): 28.8mph on 28th
Mean wind strength (at 0900):  8.4mph  
    
Winds from the Following Directions:    

N 2 NE 1 E 5 SE 2 S 11 SW 4 W 3 NW 2 Calm 1  
    
Concrete     
Lowest Concrete Minimum:  -7.1C on 20th
Mean Concrete Minimum:  -0.3C  
    
Evaporation    
Piche     47.8ml 
Pan     not available 
    
Days with:    
Thunder:    0   
Hail <5mm:    0   
Hail >/=5mm:    0   
Snow or snow & rain:   0   
Fog:     2   
Air Frost:    11
Duration of Air Frost:   57hrs   
Gales:     1

All data © Pitsford Hall weather station.

The weather station publishes a full Monthly Weather Report (ISSN 1741-4733) which is distributed to libraries across Northamptonshire. This report comprises a full UK weather diary, reports of extreme weather events across the county, statistics from Pitsford Hall's affiliated stations across the county as well as news from the weather station itself. Individuals may download this report for £2 or take out an annual subscription for the paper-based report for £25. Click here for further details.