There was heavy rain to the west of us and heavy rain to the east of us but little over Marlborough yesterday. The rain and thunderstorm radar show a rash of storms developing to the northeast of our area and drifting southwestwards, just after 12.30, with torrential five miles outside of Marlborough at 12.50, I was there at the time, but little over Marlborough. During the course of the afternoon further storms brought heavy rain further to the west over the Devizes area and Hungerford to the east. Watching the rain radar, repeatedly the main rainfall was deflected around Marlborough. This pattern I have seen on many previous occasions when storms occur, not rain bearing weather fronts, and wonder if the topography of our local area is an element to cause this repeated pattern. The total rainfall yesterday was just 3.1mm, which took the monthly total to 6.4mm against the 41-year average for May of 60.4mm, but it did half fill one of my empty water buts! There was a major thunderstorm overhead Marlborough that arrived at 17.10 with several thunderclaps until 17.25, the thunder and lightening clearly heard and seen and very evident on the radar.
There was some late afternoon sunshine around 16.00 between the storms that eventually lifted the temperature to a maximum of 18.7C at 16.58 being 1.4C above my long-term average. During the early evening the clouds dispersed and under clear skies overnight the temperature dropped away significantly to reach a low of 3.4C at 05.32, just after sunrise at 05.60 in Marlborough, being 3.7C below the average.
Thursday revealed a sunny start to the new day but variable cloud arrived just after 07.30. During the morning and afternoon a cold front will travel south across our area that will bring more cloudy conditions. There will be a brief respite on Friday as a temporary ridge of high pressure arrives but by Saturday the Atlantic systems will start to affect us having arrived further west later on Friday, signifying a major change in the weather pattern over the UK. By late Friday and over the weekend the winds will come from a westerly quadrant, not seen for over a month.
I read yesterday that the Met Office has transferred to a new off-site supercomputer – which could make 14-day forecasts as accurate as seven-day equivalents. Operating using Microsoft’s cloud-based Azure system the new computer code also help predict extreme weather further in advance, they state. For more than a month, Azure has been running off-site simultaneously with the Met Office’s previous supercomputer, which has now been switched off.