Thursday 7th May
It was a very cool day on Wednesday, followed by an even colder night than forecast, which was likely to have produced a short lived ground frost. The thermometer eventually rose to a maximum of 14.9C at 15.56, under a very brisk and cool northeasterly breeze, being 2.4C below average. Overnight the residual warmth very quickly dissipated into the atmosphere, under clear skies initially, before cloud developed across southern England just before 03.00, forming fog, and the temperature then lifting to 5.7C at 08.00.
Fog had formed in the early hours due to the lower temperature, resulting in the moisture in the air condensing, that limited visibility to around 400m at 06.30 on Thursday. The depression just to be west of Scotland will influence our weather today which will result in the wind coming from the south, but just for today. As a result the temperature will climb a little higher, that combined with a light wind, will make it feel a little warmer.
The jet stream has been the culprit for recent cool weather resulting in an air stream from a northeasterly quadrant and that pattern will continue well into next week. As it leaves America, the jet stream is looping north towards Greenland before dropping downwards across the UK, carrying with it the very cool air. Until that pattern changes, not foreseen in the short term forecast, we will come under cloudy, cool conditions.
The very low temperature in the early hours, combined with a below average maximum yesterday, has seen the little warmth there has been in the ground dissipate into the atmosphere resulting in a temperature of just 10.2C at 08.00, measured at a depth of 5cm. This situation also linked with minimal rainfall is not encouraging for plants already in the garden. The rainfall this month totals just 5.2mm, whilst there has been an equivalent loss of rainfall through evaporation from the ground and plant life of 18.1mm.