Archives For temperature inversion

HIGH pressure means air sinks, warms up as it descends and dries out: this should mean less cloud… right? Unfortunately not always. Reigate has seen very little sunshine in the last few weeks despite a persistent HIGH pressure. Stratocumulus cloud and stratus cloud has hung low over the North Downs. This low cloud has been trapped by a temperature inversion at 1000m, where temperatures rise with height putting a “lid” on the weather. Any rising air will hit this inversion and convection will stop. Clouds forming beneath the inversion will simply spread out, join up and cover the sky: creating overcast dull gloomy conditions. Once the cloud forms it is difficult to shift because, whilst the sunshines above the cloud warming the air, the cold air persists below exacerbating the inversion. A stronger breeze or drier air or a shift in the position of the HIGH will release us from this weather underworld. The good news is the weekend looks brighter with winds less likely to be blowing from a cool, damp North Sea. Sunday looks the brightest with temperatures reaching 9 or 10C by the afternoon: almost spring like. The rest of the week from Wednesday will become more unsettled, feeling warmer but wetter as the HIGH at last moves away to the south east allowing Atlantic westerlies back for a breath of wet air!

To Spring… early forecast models suggest wetter conditions with slightly below average temps for the south of England with possible frequent easterly winds as LOWS track to the south; and drier, warmer and slightly above average conditions in the north of the country.  Essentially HIGH to the north and LOW / jet stream to the south of the country which will keep the south cooler and unsettled with the north enjoying better weather.  In short, more of what we had in late winter, just a warmer version?! Updates later.


Anti-cyclonic stratocumulus cloud continues to blanket Reigate and the SE of England in a cold, gloomy weather underworld.  A temperature inversion (where temperatures rise with height, instead of fall) at 1000 metres is trapping any rising air which inhibits convection spreading out the cloud mass to cover the entire sky: good to reduce rainfall, bad for any views of the sun!  Regrettably no light at the end of the tunnel yet: the north-easterlies circulating round the HIGH pressure to the North are likely to continue for much of the week and bring in blankets of stratocumulus cloud from the North Sea. This spectacular view from the EU Meteosat satellite today at midday clearly shows the cloud blanket voering SE England from 22,300 miles away.
Temperatures will struggle to exceed 5C in the days to come; this time last year temperatures were well above 12C and even hit 17C on a few days.