Tag: March

March began with very cold days and several nights with air frost, which combined with strong winds produced several days with significant wind chill of -5°C and -7°C on the 5^th and 7^th respectively. It was only when we reached the 8^th did temperatures recover to near normal monthly temperatures. As pressure rose from mid-month so did the occurrence of warm days with light winds, which were very pleasant for March. The maximum temperature was 18.3°C on the 25^th.

The mean temperature was 0.3°C above the long-term average which was principally due to the mean maximum being +1.3°C whereas the mean minimum was -0.6°C. This was the driest March I have recorded. The total of just 12.7mm was almost 3mm less than the previous record of 15.6mm that fell in March 1997.

My recent analysis of wind speeds over the last ten years show that there have been significant changes, especially since 2008. The average annual wind speed for the years 2001 – 2006 fluctuate between 4.3mph and 4.6 mph. However, the years 2008/09/10 produced falling values of 3.9mph, 3.3mph and 3.1mph respectively. I discovered that during the winter season the incidence of 20mph+ gusts had fallen by four and 30mph+ gust by three. A recent meteorological report suggested that these falling values over the last three years or so were due to “a spell of subdued westerlies with a weak and contorted middle-latitude jet stream”.

Consistently high pressure until the 17^th brought cold and dry weather as the anticyclone blocked fronts advancing from the Atlantic. The dry, strong mainly northerly winds produced just 1mm of rainfall over the sixteen days but gave us eight nights with air frost. The remainder of the month brought very different weather with just one dry day between the 18^th and 31^st. A maximum of 14.6°C was recorded on the 18^th with the coldest night experienced during the early hours of the 5^th when the thermometer fell to -6.7°. The wettest day was the 24^th with 14.3mm. The total rainfall for March was 70.5mm, which is 118% of the long-term average. Due to the persistent northerly winds it was a cold month with the mean temperature 0.5°C below the long-term average.

March provided us with a wide variety of weather. The first couple of weeks, with low pressure predominating, brought maxima near average but depressed night time temperatures with several frosts and the majority of rainfall for the month. The wettest day occurred on the 3^rd with 16.8mm of rainfall, which was 40 % of the total for March. A spring like week started on the 15^th with warm, dry days and much sunshine all due an anticyclone which also provided eight consecutive days without rainfall. The remainder of the month brought near average maxima but some sharp frosts, namely -3.8°C and the coldest of -4.6°C on the 30^th and 21^st respectively. There were eleven air frosts which is three above the long-term average. The mean temperature was just 0.2°C above the long-term average and the total rainfall of 41.6mm was only 69% of the long-term average. The aquifer rainfall, from 16^th October – 15^th March, which is generally recognized as the period when rainfall drains through to the aquifer rather than evaporating, was 45mm below the long-term average and the driest since 2005/06.