Category: Commentary

The wedge of mild air on Monday resulted in the thermometer rising to 10.5C at 12.39 during the bright intervals and weak sunshine that was 2.4C above the long-term average whilst thin cloud eased in during the afternoon. Under clearing skies the temperature dropped away during the evening reaching a minimum of 2.3C at 02.33 being 0.1C below average. However, a significant change then occurred as the wind swung into the south and began to pick up speed, nothing major. The cloud that drifted across stopped the warmth dissipating into the atmosphere that combined with the flow of warmer air from the south saw the thermometer make an about turn and begin to rise reaching 8.6C at 08.00. There was a minimal amount of precipitation that was not measurable so recorded as a ‘trace’.

Tuesday revealed a cloudy and dull start to the new day with the wind still coming from the south due to the recent high pressure relocating south and east to North Africa. It is very moist air with humidity 100% at 08.00, the first this month. The barometric pressure has dropped 6mb as the anticyclone slips away.

Thicker cloud has arrived today ahead of two weather fronts that will arrive during the late afternoon and evening bringing rain and increasing wind strength overnight and into Wednesday.

A wedge of mild air covered the UK on Sunday that saw the thermometer rise steadily to reach a maximum of 11.4C at 13.35 being 3.3C above my 40-year average. This was the warmest day since the 7th. The low overnight was likewise above average, in fact significantly above, with a minimum of 8.7C at 07.48 early Monday, being +6.2C. It was dry by day however, a little brief, light rain fell overnight amounting to 0.6mm.

The cloud on Monday after dawn was much thinner and higher although the radar projects few breaks in that cover during the day. In fact the next depression is in mid-Atlantic, easing towards us and beginning to throw light cloud in from the west. The high pressure is still moving away, its centre is projected to move from southern France to the Mediterranean, as a result the wind will back from west to west-southwest and then southwest as the day progresses and be modest in strength. The barometric pressure at 08.00 read 1032.0mb, the highest for four days.

The wedge of moist Atlantic air will continue for possibly three days with warmer days but possibly cooler at night if the cloud cover breaks.

Saturday started cloudy, as on previous days, but late morning the cloud eased away and very welcome, intermittent sunshine arrived, the first all week, this raised the temperature to 6.9C by 13.05 and then dropped away to a minimum of 5.4C at 19.45. However, during the evening and early hours this was reversed and the thermometer climbed slowly to reach a maximum of 9.5C by 07.46 early Sunday. This was the first above average maximum since the 7th (+1.4C). This change was due to the wind backing from northwest to west after 17.00, a warmer air stream. The brighter afternoon saw UV light trigger the sensor for the first time in a week.

Sunday after dawn revealed a cloudy sky but this was higher and thinner than previous days and might thin further after a warm front eases away as the day progresses. The wind will continue from the west all day and modest in strength.

The milder conditions should be with us until midweek as the recent high pressure has relocated to the Bay of Biscay so the wind circulating clockwise around its centre is feeding us warmer, but moist air from that region of the Atlantic. The barometric pressure has risen to the highest for three days with a reading of 1027.9mb at 08.00. The soil temperature at a depth of 5cm, has risen to 7.3C at 08.00, thanks to the warmer air, the highest since the 5th.

Friday was the last of the persistent gloomy days with low cloud and no sunshine. The diurnal variation was minimal yet again with a difference of just 1.1C with the high at 5.5C being 2.5C below average and the low of 4.4C was 1.9C above average. Light rain and drizzle began at 12.15 and persisted during the afternoon and into the evening amounting to 4.1mm that took the monthly rainfall to 39.6mm when the 40-year average is 94.0mm.

Saturday began as all the days this past week with low cloud and misty conditions. However, changes are afoot as the wind for much of the daylight hours will come from the northwest heralding an improvement as the day progresses with some sunshine likely. At last the persistent anticyclonic gloom will disappear.

Thursday was the sixth successive day with thick, low cloud that meant no UV light triggered the sensor. Like previous days the temperature varied little between night and day with the diurnal range just 1.1C. The maximum of 6.5C was logged at 19.26, being 1.6C below average and the minimum of 5.4C at 07.48 early Friday, being 2.0C above the long-term average. The precipitation amounted to 0.9mm from mist and light drizzle early Friday. The thermometer edged upwards just after 17.00 as a warm front arrived that raised the temperature 0.5C to its peak of 6.5C. Just after 01.30 early Friday the temperature started to ease downwards again. There was one significant change compared to previous days in that there was almost a complete absence of wind, with the anemometer occasionally coming alive indicating 1mph or 2mph for many hours, the peak movement was just 8mph.

Friday started even duller than previous days, if that was possible, as the cloud was even lower and thicker from a wide band of mist and light drizzle extending from London, west to North Devon. The cloud draped the Marlborough Downs and Savernake Forest with continuous light drizzle in the misty conditions.

The recent high pressure has been easing away dropping 6mb in the last twenty-four hours. As a result of that repositioning the wind will at last veer from the northwest that was persistent for the past four days to southeast and south with it moving future clockwise to southwest this evening, bringing a less cold flow of air. We will have to wait until Sunday for temperatures by day returning closer to normal.