What is anticyclonic gloom and why is it causing our weather to be so miserable?
Who would have thought that this quiet and stagnant November weather could generate any news at all? But rather than the usual wind, rain and storms so typical of the season, it's the lack of movement of weather that's now capturing the headlines because that lack of movement is creating a staggering lack of sunshine. Why is the weather so gloomy?High pressure over the UK is trapping moisture near the surface of the Earth, creating stubborn cloud or, in weather parlance, 'anticyclonic gloom'. High pressure give us little to no wind so there is nothing to move the cloud around or break it up. How little sunshine are we talking?For some, there has been no respite at all - Odiham in Hampshire has recorded 0 minutes of sunshine so far this November! Wales takes the unenviable second place spot with an average of just 12 minutes! 48 minutes recorded in Northern Ireland and only a touch more in southern England with 54 minutes. By comparison, eastern Scotland has captured the lion's share of the brightness, racking up a whopping 11 hours of sunshine in the first week of November.How about the temperatures?The thick cloud blocking out the sunshine has affected our daytime heating and therefore our temperatures too - essentially we need the heat of the sun to warm the Earth. At the start of the month we were sitting in a relatively mild airmass which somewhat offset the lack of sunshine.
In the last few days, however, that dominant area of high pressure shifted slightly to draw in cooler air. The combination of lack of sunshine due to the cloud and the chillier air will result in temperatures that, for many, struggle to rise out of single figures by the middle of next week.How about nighttime temperatures so far?
The opposite is actually true overnight. The cloud cover works to retain heat overnight, acting as a blanket and preventing the (comparatively) warmer air drawing away from the earth's surface.
Night-time temperatures, so far, have been well above average - have you noticed the lack of overnight frosts? The difference between our maximum day and night temperatures is called the 'diurnal range' and this will be relatively small over the next few days and nights which is unusual for the time of year. How about next week? Weather fronts moving in on Sunday will clear the layer of stubborn cloud, or ‘anticyclonic gloom'. A new area of high pressure will start to build on Monday, with drier, clearer air, and sunshine for most parts of the UK.
Temperatures will be closer to average, but the lack of cloud means it will be colder overnight with frosty conditions for many. A large and far more typical diurnal range!
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