Saturday 27th June
Friday was another very hot day, but as suggested yesterday morning, it did not quite reach the peak of previous days, in fact, with a maximum of 33.3C it was the lowest high since Monday even though it was 12.5C above average. There was a significant change in wind directions as the day progressed, to come from a more westerly quarter, indicating that the change was beginning. The minimum of 15.6C at 05.38 early Saturday, before sunrise in Marlborough at 04.52, was only 5.4C above average that made it the coolest night since the 21st when the heatwave began.
Saturday began with variable sunshine that had lifted the temperature to 22.2C by 08.00, making it the coolest start to a day since Monday. Cloud is likely to build after around midday as Atlantic depressions are edging closer. Even so, the maximum will still be well above average but perhaps 6C below the highs of the past week.
The data underlines why we have been under a Red heat warning. At 16.30 yesterday, although a radiation shielded thermometer indicated an air temperature of 32.3C in fact outside it felt more like 39.4C when taking into accept air temperature, humidity, wind and solar radiation. At a much earlier time in the afternoon the difference would have been even greater.
The high pressure is being reluctant to depart having risen 5mb since yesterday with a reading of 1018.1mb at 08.00. However, the forecast surface charts indicate that on Sunday we will became more under the influence of low pressure to the west, edging in from the Atlantic, that will throw the first weather across the country for over a week, on Sunday. As it is a cold weather front, the result will be a much cooler day with the maximum close to the June average, likewise the minimum overnight, so much more comfortable. It is only after the cold front passes through on Sunday morning that the distinctly cooler air arrives. The weather front will carry with it cloud that will obviously limit sunshine after the wall to wall sunshine of the past week.
Looking forward, the forecast surface pressure charts indicate that although the Azores high will try and push a ridge of higher pressure across the country on Monday, the coming week will see weather predominantly from the Atlantic on a southwesterly or westerly air steam with variable sunshine and little indication of any rain at the moment, also temperatures around or just above the June average.
The Met Office has issued its long range weather forecast for July, offering insight as to whether another heatwave will grip the UK.
• It comes after the record for the hottest June day was broken on three consecutive days, with temperatures reaching 36.9C in Wattisham, Suffolk on Friday.
• According to the agency, temperatures during the period of 11 to 25 July are “likely to be above normal on the whole, with a greater than normal chance of hot conditions developing at times.”
• It adds that there is potential for “changeable or more unsettled conditions developing later in the period, with a risk of some heavy and thundery showers.”
• Scientists have warned that the UK may well see temperatures of up to 45C in the near future, with Dr Eunice Lo, Senior Research Fellow in Climate Change and Health at the University of Bristol Cabot Institute for the Environment, adding: “We must adapt to hot weather now, as it is going to increase in intensity and frequency due to climate change.”