If things have felt especially gloomy this week, it’s not just the politics.
The grey mist that seems to have descended is down to an outlier weather event that has been under way since the start of November, which has seen some regions of England record just a few minutes of sunshine this month.
A continual period of “anticyclonic gloom” is the reason for the dreary overcast conditions of fog, drizzle and low cloud, according to the Met Office.
“There’s not been anything hazardous that we have to warn for, so it’s not anything people need to worry about but constant grey skies and no sunshine probably doesn’t do any good for people’s mental health,” said Jonathan Vautrey, a meteorologist at the Met Office.
Among the gloomiest areas has been the village of Odiham, Hampshire, which has recorded just 12 minutes of sunshine in the past 11 days, and Rostherne, Cheshire, where the clouds have parted for a mere 24 minutes. Besides two hours of rare sun, anyone arriving at Heathrow airport will have been met by mist and low cloud, while England, as a whole, has experienced less than a 10th of its expected sunshine for this time of year.
The continual meteorological gloom has been brought about by a period of high pressure, characterised by air descending to form acentre of higher pressure, with light winds blowing in a clockwise (anticyclonic) direction towards surrounding regions of lower pressure. In summer, the downward air flow means little cloud formation occurs and this tends to usher in bright, clear, warm weather.
But in autumn, when there is more moisture in the air, it can instead mean a spell of low cloud, mist and drizzle.
“It can trap a layer of moist air at the surface,” said Vautrey. “High pressure itself can be a blocking pattern. You can get it sat over one particular location for a long period of time.”
While bright sunny weather is often assumed to lift our mood, the scientific evidence for this is marginal, although one study suggests we’re more likely to feel tired in cloudy conditions. There is a stronger case for spending time in natural daylight (even when overcast), which is essential for vitamin D production and helps regulate the body’s circadian rhythms.
Either way, on Sunday, the mist and clouds are expected to be swept aside as a new weather front moves in from the north-west and moves south-eastwards. “Behind that we’re introducing some much fresher conditions,” said Vautrey. “It will help clear out all the grot and the cloud that’s around at the moment.”
