Category: Commentary

The rain eased away on Friday but still produced another 4.9mm of rainfall bringing the monthly total to 66.5mm being 13mm above the 36-year average. The convergence of two air streams on Thursday, from the cooler drier air mass from the east and warm, moist air mass from the south converged over southern England producing the exceptional rainfall.

With minimal sunshine, just 4.6 hours, but mostly cloudy, the temperature was depressed by day with a peak of 18.3C, which was 1.6C below the average.

Overnight was another mild night due to the cloud cover with the thermometer not sinking below 11.5C, which was 1.C above the average,

Saturday after dawn saw thick low cloud but by 08.00 bright periods were appearing as a temporary ridge of high pressure took effect. The barometric pressure has been rising for the past twenty-four hours.

The rain on Thursday began before 05.00 and stopped just after 18.30. However as the low pressure area slowly circled anticlockwise and moved ever so slowly westwards, the tail of the very wide rain band came back to the area in the early hours of Friday, light at first but more persistent and heavier rain from 06.00. The total rainfall for the twenty-four hours was 33.8mm. This was the wettest day since 18th September 2014 when 40.6mm fell in one day. The total rainfall for June has reached 61.6mm, which is 8mm above the 36-year average. At its peak the rain was falling at a rate of 90mm/hour.

Due to the slack area of low pressure winds were light for most of the period but as the depression circled the area the wind began the day from the southwest then veered into the North and eventually into the south late in the afternoon.

This was the first day without measurable sunshine since 28th April.

With all the cloud and rain the daytime temperature was depressed that meant a maximum of only 14.9C. This was the second coolest day in June and 5.2C below the 36-year average. Conversely, the thick, low cloud meant a mild night with a minimum of 12.4C being 2.4C above average.

As commented above, Friday morning saw the wet conditions continue with modest, continuous rain.

Although the sunshine was more restricted on Wednesday, with just 5.9 hours as compared to previous days, the warm moist air, combined with little wind and modest sunshine allowed the thermometer to climb to 23.1C. This peak was 3C above average.

Thunder was first heard at 15.57 with numerous claps of thunder to follow. The rain began to fall heavily at 16.15 and continued for perhaps 15 minutes producing 3.1mm. During this period the thermometer dropped from 23.1 to 18.8C.

Another mild night followed with the thermometer not falling below 13.8C making it the warmest night since 26th September.

There were brief, light showers after midnight but substantial rain began to activate the rain recorder at 05.15 so that by 08.00 on Thursday the total precipitation for the past twenty-four hours amounted to 11.4mm making it the wettest day since 30th April. The rain intensity eased but continued after this time on Thursday morning.

Tuesday again provided a mainly sunny day with 10.4 hours of sunshine and the third warmest day this month with the thermometer rising to 23.6C being 3.5C above average.

A significant rain band moved northwestwards just to the north of Marlborough for a signifiant time when five bursts of thunder were heard between 16.14 and 16.25 but no rain fell here. A light shower did occur just after 17.30 amounting to 0.5mm.

The rainfall for June stands at 16.4mm whilst the equivalent rainfall lost through evaporation from the ground and plant life amounts to 50mm.

With a below average minimum in the early hours of Wednesday after the light rain the previous evening, fog formed that varied intensity but thickened to 100mm visibility at 07.00. By 08.00 on Wednesday the fog had all but evaporated as the sun broke through and lifted the thermometer to 13.9C

The southerly air mass brought on very light winds, combined with 11 hours of strong sunshine, produced a maximum of 22.9C, which was 2.8C above the average. The UV level rose to 8.5 at midday which was ‘Very High”. The strongest movement of wind, cannot be called a gust, was 11mph and died away completely overnight.

A very mild night followed with a minimum of 13.5C, the warmest night since 26th September and 3.5C above average.

Tuesday saw strong sunshine after dawn that by 08.00 had lifted the thermometer to 18.2C making it the warmest at this time of day since July 26th. Not surprisingly the ground temperature at. depth of5cm was 20.6C, not seen since 24th July.