The rise in temperature on Monday was limited by the cloudy conditions that built up around midday with a maximum of 17.6C at 12.37 being just 0.3C above average. The peak UV value of 7.3, the highest since 11th August 2024, took it well into the ‘Very High’ category, but only for a brief period before the clouds thickened and rain showers arrived again, the first at 10.30 then 14.30 and a more consisted fall at 17.00, which in total amounted to 5.8mm making it the wettest day since 28th February. That fall then took the monthly total to 14.6mm compared to my 41-year average of 60.4mm. The past night was very mild that saw the thermometer not drop below 11.7C at 05.2, thanks again to the overnight cloud cover under the hang back of cloud from the weather front.
Tuesday arrived with continuing cloud cover from the unsettled weather as we are still under the influence of the depression to the north of the UK. The rain radar at 08.00 showed heavy rain moving in from the west, already having reached Devon, and making its way to southern England mid-morning, with hopefully for gardeners, a substantial fall. Currently the rain radar indicates that the weather front is fragmented so not sure how consistent the rainfall will be as it crosses from the West Country.
The depression, with its centre just north of Scotland, had a centre pressure of 976mb at midnight, compared to the anticyclone in the eastern Atlantic, reaching across into France, with a centre pressure of 1031mb. This considerable pressure gradient is producing the string winds, that will strengthen in the gusts ahead of the rain arriving mid-morning. The airstream is circulating anticlockwise around the depression and clockwise around the high pressure, as they do, hence the wind from a southwesterly or west-southwest direction today. The barometric pressure at 08.00 read 1012.9mb. There are indications from the rain radar that this approaching rain band will bring a more consistent and heavier fall of precipitation lasting for several hours.
It will all change on Wednesday as the low pressure gives way to a temporary ridge of high pressure that will bring us a much warmer and drier day.
Bowood Gardens, near Calne in Wiltshire, has a large area of varied rhododendrons that are spectacular at this time of the year.