Author: Eric Gilbert

Sunday was not as hot as Saturday with a peak of 25.1C, however, this was still 4.9C above the 39-year average. The wind had veered into he northwest, a direction not seen for a month and was very light with a maximum gust of just 10mph, also the lowest for a month.

A modest shower, lasting for just over half an hour, fell early evening at 19.00. The centre of the intense storm was just to the east and travelled northwestwards towards Swindon in a long line of shower cells. Thunder was heard for over half an hour in the distance. More rain fell after midnight, 01.00, and a heavier burst at 02.15 falling at the rate f 25mm/hour. The rainfall total for the day and night was 5.5mm.

Monday began with misty conditions after the rainfall but by 08.00 the sun was beginning to burst through the cloud cover and had lifted the temperature to 17.4C at 08.00 after a minimum of 15.3C at 05.11, which was 5.2C above the average. The wind today is forecast to come principally from the southeast.

The temperature steadily rose to a maximum of 29.8C at 15.02, which was 9.6C abject he average, before cloud began to arrive from the southeast and the first light drops of rain were observed. This was the hottest day since the heatwave in August 2022 when when 33.5C was noted on the 13th.

A classic Line of Convergence was seen on the radar screens at that as the hot, moist air from the Continent, brought on a southwesterly air stream, met the colder, drier air from the northeast, that had been plaguing our area for the last three weeks. The warm, moist air, being lighter, rose above the colder air mass and rapidly condensed forming storm cells that brought the first rain drops at 15.10. Further cells developed in a line to the southeast and moved northwestwards across our area, due to the wind veering from northeast to southeast, with heavy rain from 15.40. A total of nine thunder claps were heard during this period.

The showers, sometimes very heavy, produced 9.3mm of very welcome rainfall for the gardens and filled three of my 220 litre water buts. The rain eased and ceased at 17.05 and the sun began to reappear, weakly at first.

During the storm period the air temperature fell precisely 10C from 29.9C to 19.9C. The thermometer began to rise again at 17.05.

The warm air mass meant a very mild night with the thermometer not sinking below 15.7C, which was 5.7C above the average.

Sunday dawned with misty conditions and weak sunshine through variable high cloud. By 08.00 the thermometer had risen to 19.3C.

Although the wind continued to arrive from the north east, the warmer airstream from the Continent pushed the thermometer to a maximum of 26.0C at 17.15. That peak was 5.3C above the 39-year average and the warmest day since 24th August. A gust of 24mph at 14.34 was the strongest gust since the 30th May.

The warmer airstream meant a mild night with the thermometer not sinking below 12.4C, which was 2.3C above the average and the first above average minimum this month.

Variable sunshine greeted the start of Saturday with the thermometer already reading 16.3C at 08.00.

The rate of evaporation has increased with the warmer air and strong breeze. For the last two days the equivalent loss of 4.5mm of rainfall has been lost to the atmosphere daily. So far this month the total evaporation has been 33mm.

Update at 17.30: a classic Line of Convergence was seen on the radar screens this afternoon as the hot, moist air from the Continent, brought on a southwesterly air stream, met the colder, drier air from the northeast, that had been plaguing our area for three weeks. The warm, moist air, being lighter, rose above the colder air mass and rapidly condensed forming storm cells that brought the first rain drops at 15.10. Further cells developed to the southeast and moved northwestwards across our area, due to the wind veering from northeast to southeast, with heavy rain from 15.40. A total of eight thunder claps were heard during this period

The showers, sometimes very heavy, produced 9.3mm of very welcome rainfall forthe gardens and filled three of my 220litre water buts. The rain eased and ceased at 17.05 and the sun began to reappear, weakly at first.

During the storm period the air temperature fell precisely 10C from 29.9C to 19.9C. The thermometer began to rise again at 17.05.

Thursday gave us the warmest day since 3rd September with a maximum of 22.4C, which was 2.2C above the average. The northeasterly persisted again peaking at 20mph.

The past night has been much warmer with the thermometer not sinking below 9.3C, which was 0.8C below average.

The anticyclone continues to fade and the depression that was Storm Oscar is beginning to feed a warmer airstream across the area although the northeasterly is still brisk but due to veer into the east later today and then southeast.

Friday commenced cloudy but by 07.15 the sun began to break through that lifted the thermometer to 12.8C at 08.00 the warmest start to a day since 11th May. The barometric pressure continues to fall with a pressure reading of 1014.8mb at 08.00 as the remains of Storm Oscar approaches.

Little change from previous days on Wednesday although it was a little warmer with a maximum of 21.1C, just 0.9C above the average.

The past night was similar to previous nights with a minimum of 8.2C with cloud rolling in during the early hours.

Thursday was initially gloomy with total cloud cover but the first burst of sunshine arrived at exactly 07.00 with more as the next hour progressed.

The blocking high pressure is beginning to loose its grip and move away as Storm Oscar pushes up from the south. The barometric pressure reading of 1019.9mb at 08.00 was the lowest reading since 11th May.

We have now had 24 consecutive dry days making it the longest dry spell since September 2002. However, drier spells were recorded in April 1997 with 28 dry days and the record set in March 1984 with 37 consecutive dry days and only 2mm of rainfall in the month.

A ‘Yellow’ heat alert has been issued from 09.00 on Friday to alert the public of high temperatures over the next few days. This is the lowest level of alert when the heat will have no major impact on most people.

17.00: Yellow heat alert upgraded to Amber.