PITSFORD HALL WEATHER STATION NORTHAMPTON, UNITED KINGDOM MONTHLY WEATHER REPORT - NOVEMBER 2001 Headline: An early cold spell with snow falling on the 8th and turning unseasonably mild towards the end of the month. Slightly below average rainfall under mostly anticyclonic conditions. November open with a reasonably dry, mild and sunny week with pressure high over the region. Sunshine values at Pitsford Hall clocked in at 7.5 hours on the 1st and 4th and daytime maxima reached 14.0C on the 1st and 3rd. Some very wet weather introduced the second week associated with an active low tracking eastwards towards Denmark. The 7th was particularly wet with 7.3mm falling over 6.3 hours. Strong northerly winds also picked up with gusts of 44 mph recorded on the 7th and 49 mph recorded on the 8th. The strong northerlies brought temperatures tumbling with a daytime maximum of just 5.2C recorded on the 8th, a day which also saw the first flurries of snow in the county. The 9th and 10th remained dry as a ridge of high pressure took charge. Clear skies overnight saw temperatures fall sharply to below freezing. A cold front moved through the county on the 12th bringing further pulses of rain and cold polar air. The high pressure which developed following on from this brought a period of calm and settled conditions across the county. Despite some lingering mist in the mornings, there were days with good sunshine and the clear spells by night saw several frosts, the hardest being on the 14th with grass temperatures falling to -6.2C. Increasing cloud on the 16th heralded a spell of traditional anticyclonic gloom which lasted until the start of the 21st. The start of the 4th week was rather changeable. Mean temperatures fluctuated widely as a succession of fronts tracked across the region. Despite some cold nights on the 26th and 27th with ground frosts recorded as low as -4.9C (26th), increasing cloud and south-westerly winds eventually brought in milder conditions, culminating in an unseasonably warm day fuelled by strong southerly winds on the 30th. Climatological & Agromet Statistics - November 2001 Air Temperatures The Highest Maximum: 15.0C on 30th The Lowest Maximum: 5.2C on 8th The Highest Minimum: 10.6C on 30th The Lowest Minimum: -2.2C on 10th The Mean Maximum: 10.6C The Mean Minimum: 3.2C The Overall Mean: 6.9C Difference from the Monthly Mean: 0.0C Relative Humidity: Highest Relative Humidity (at 0900): 100.0% on 15th Lowest Relative Humidity (at 0900): 63.6% on 10th Mean Relative Humidity (at 0900): 93.4% Dew Point: The Highest Dew Point (at 0900): 12.4C on 30th The Lowest Dew Point (at 0900): -3.6C on 10th The Mean Dew Point (at 0900): 5.1C Rainfall: Total: 43.8mm Difference from the Monthly Mean: 82.2% Duration: 37.7 hrs Highest 24-hour fall (from 0900): 9.2mm on 29th Rain Days (>/=0.2mm): 13 Wet Days (>/=1.0mm): 9 Lowest pH: 5.60 on 27th Sunshine: Total Duration of Bright Sunshine: 75.7 hrs Sunniest day: 7.5 hrs on 1st & 4th Sunless days: 11 Cloud cover (mean at 0900): 5.8 oktas (72.5%) Pressure (reduced to sea level): The Highest Pressure: 1044.7mb on 16th The Lowest Pressure: 996.3mb on 8th Mean Pressure (recorded at 0900): 1023.7mb Winds: Run of wind (mean over 24 hrs): 102.6 miles Mean daily wind speed: 5.6mph Highest 24-hour Wind Speed: 14.5mph on 8th Run of wind (to date): 3077.3 miles Highest Maximum Gust: 49mph on 8th Highest wind strength (at 0900): 23.1mph on 8th Mean wind strength (at 0900): 8.2mph Winds from the Following Directions: N 4 NE 2, E 1, SE 0, S 6, SW 2, W 4, NW 10, Calm 1 Days with: Thunder: 0 Hail less than 0.5mm: 0 Hail greater than/equal to 0.5mm: 0 Snow or snow & rain: 1: 8th Snow lying: 0 Fog: 2 Air Frost: 7 Duration of Air Frost: 32 hrs Ground Frost: 16 Evaporation: Total evaporation (tank): 12.14mm Ground Temperatures: Lowest Grass Minimum: -6,4C on 10th Mean Grass Minimum: -0.4C Lowest Concrete Minimum: -5.4C on 15th Mean Concrete Minimum: 1.5C Lowest Bare Earth Minimum: -2.3C on 27th Mean Bare Earth Minimum: 2.8C Soil/Earth Temperatures: Surface mean: 5.1C 5cm mean: 6.0C 10cm mean: 6.8C 20cm mean: 7.7C 30cm mean: 8.2C 40cm mean: 8.3C 50cm mean: 8.9C 100cm mean: 9.8C Climatological observations made at 0900 UTC. Averages refer to the period 1971-2000. All data © Northamptonshire Grammar School.