Cold December and a cool 2010

  • Cold December and a cool 2010
    31.12.2010 09:32

    Many people in Northern Ireland will need no reminding of how abruptly the weather can alter our circumstances, nor how its extremes can interfere with even the fundamentals of life such as tap water.

    It has been a remarkable December, with much more snow than recent years and much lower temperatures. Castlederg, County Tyrone, plummeted to Northern Ireland’s lowest ever recorded temperature, -18.6 degrees Celsius on the morning of December 20.

    Although individual records were not broken anywhere else in the UK, it looks like December will be the coldest since 1890, with 2010 as a whole the coolest since 1986. Lest we forget, the first two months of the year were also often very cold and snowy, and a warm period from mid-March to mid-July could not make up for the frigid start and end to the year.

    Through the rest of July and right into October temperatures were near average, and it was rather wet, as many families holidaying at home will recall. Then came a gradual fall in temperature below average during November, and a sudden plunge after about November 25, with snow coming before winter had even begun.

    The snowfall that followed may have seemed abnormal given that we had been getting used to relatively mild winters through the past couple of decades, but it would not have been viewed as particularly remarkable alongside some of the snowstorms of the twentieth century.

    Given the poor late-summer and autumn and sudden start to winter it might seem surprising to learn that the UK had a drier and sunnier year than average, if not all that warm. This is partly due to the relative infrequency of winds from our usual prevailing directions between southwest and west, which can bring a lot of rain to north-western parts of Britain, especially the uplands.

    The weakness in the westerly flow is also what allowed such a propensity of very cold northerly and easterly outbreaks in the late autumn and the winter.

    As far as 2011 is concerned it is impossible to say what the weather has in store. Nobody can say with any certainty whether or not the atmospheric arrangements that brought us such a strange 2010 will persist.

    It is hard even to judge January’s developments. Temperatures are going to drop again as soon as the New Year gets underway and might not be in too much of a hurry to rise again. There are some indications that they will eventually, and it will turn out on average to be less cold in January than December, and also less snowy; but we await the return of our old south-westerly winds.

    By: Stephen Davenport