Wednesday 17th December
After a wet morning on Tuesday the afternoon dried up with brief sunshine. The temperatures this past month, or more, has been all over the place and not always followed a regular pattern of warmer by day and colder by night, due to the frequency of weather fronts that have continually passed over the UK from the Atlantic. After 08.00 on Tuesday the temperature dropped to 6.3C at 10.00 before steadily rising to a peak of 7.4C at 13.45. There was then a slow fall in the afternoon and initially overnight to reach a minimum of -1.4C at 03.43 early Wednesday. At that time the thermometer did an about turn and began to rise again, due the cloud drifting in from the west ahead of the next weather front, that resulted in a temperature of 2.4C at 08.00.
At first light on Wednesday a brief area of blue sky could be seen on the eastern horizon, the last of the overnight clear skies that had produced an air frost, which was being overtaken by the thin cloud ahead of the two weather fronts edging in from the west. These will be warm fronts that will lift the temperatures again, well above average, as we approach the evening following the cold start. The rain band will arrive probably late afternoon and last for several hours, until after midnight. After a few hours with the wind from a northerly quarter on Tuesday, the wind today will come from a warmer direction today, a southerly quadrant.
A very deep depression is forecast to head between Scotland and Iceland tomorrow that will push another rain band, a vigorous rain band, across the country late afternoon on Thursday that could produce a substantial fall of precipitation accompanied by strong winds as there will be a significant pressure gradient between the centre of the depression, forecast to be as low as 953mb, and the departing high pressure, which this morning at 08.00 read 1016.2mb.
The usual ritual of asking forecasters if we might have a white Christmas this year started at least two weeks ago. I have analysed my snow records, that go back to the year 2000. I found that snow fell on Christmas Day in Marlborough on just two years, namely 2001 and 2004. There have been seven years when snow has fallen in December since 2000.