Weather report

AS happened in 2010, cold weather at the end of November 2016 continued into December. The Meteorological Office’s earlier statement anticipating a colder than average winter seemed to be on track. A temperature of minus 4.6C (24F) first thing on December 1, rising to only 2C (35F), with fog all day in Wellington, did not bode well. In the shade, ground stayed frozen for the next few days, in spite of unbroken sunshine on Sunday December 4. Was snow in the offing? Answer: No.

December 6 saw very mild air from the south-west flood across much of Britain, as a large anticyclone settled over France. During the following three days and nights, temperatures in Wellington ranged between 10-14C (50 – 57F), ridiculously high for the time of year. Some weather observers on the Somerset coast recorded maxima of 17C (63F), which would have challenged the national record, if verifiable.

This launched a three-week spell without any frosts at all. It was mostly dull, and there was some (mostly light) rain every day from December 7-15. December 10 was very gloomy, with drizzle and rain amounting to 7mm (0.27 ins), while the same amount fell in a short time about midday on December 15. These two falls accounted for almost half the month’s final total, only five other days having more than 1mm (0.04 ins). With high air pressure never far away, any rain-bearing fronts became very weak by the time they reached our area.

Lack of wind was another feature of the month, again linked to the anticyclonic conditions. In a normal winter, areas of high air pressure tend to lie to the east, feeding cold continental air over us. This happened only in the first four days of December, such wind as there subsequently was coming from between south-west and north-west, depending on where the ‘high’ was centred. Even Storm Barbara that battered Scotland on December 23 gave us only a few hours when the west wind became strong and gusty. Another consequence of the general lack of wind was that everything, including washing on the line, seemed to remain damp.

Forecasts that Christmas Day might be the warmest ever in the UK proved to be over-optimistic, although a temperature of 13C (55F) in Wellington was the second highest recorded here on that date in the past thirty years. Things then cooled off significantly as polar air edged southwards, and the final week of the year was much sunnier after the clearance of morning fog. There were some sharp frosts, and a maximum of just 3C (37F) on December 27.

So ended a very odd month, nearly 1.5C warmer than average with a mean temperature of 6.0C (43F) – our sixth successive mild December. The total rainfall of 30mm (1.2in) was a mere 26% of the average, and the second lowest December figure in this area for more than sixty years.

2016 as a year was also quite strange, ending up among the ten warmest on record in our region, in spite of the cold spring.

Although the number of days with measurable rain was about normal, amounts tended to be small. The total rainfall was 14% below average at 833mm (32.8in), of which one-third fell on just ten very wet days. In this area there have been only nine drier years since 1960.

On New Year’s Day, the water level at Clatworthy Reservoir was still more than 4 metres down, not as low as at the end of 2010. But, unlike in 2011, the current outlook suggests that January too is likely to be drier than average here.

SIMON RATSEY

WWN weather correspondent