Category: Commentary

Thursday brought the penultimate dry and sunny day that saw the thermometer rise to a maximum of 18.2C early in the afternoon, between bursts of sunshine, being 0.9C above my long-term average. During the strong sunshine, between 13.13 and 13.15, the UV level rose to a value of 6 being in the ‘Very High’ category for the first time this year. With clearing skies again overnight, after the cold front had passed through, the warmth dissipated into the atmosphere under minimal cloud cover so that by 05.14 a very low temperature for May, of 1.9C, was logged being a significant 5.1C below my long-term average.

The start to a new day on Friday revealed broken light cloud cover that raised the temperature to 12.7C by 08.00.

This will be the last day under a high pressure system, which will slowly dissipate during daylight hours as Atlantic weather systems make their way towards the UK. A warm front is forecast to reach the western approaches during the evening bringing cloud that might produce a little rain overnight, quantity unsure. This will herald the arrival of unsettled weather over the weekend and into next week with winds for the first time for a month coming from the southwest rather than the recent persistent cool northeasterly breeze.

It was reported yesterday that the recent warm weather had resulted in a ‘marine heatwave’ in the seas around the UK and Ireland with some areas now 4C warmer than normal, with potential implications for marine life. The heatwave is most intense off the west coast of Ireland as well as pockets off the coast of Devon and Cornwall. The sea temperatures were the highest recorded during April and May since monitoring began 45 years ago.

Abbotsbury Swannery: While the swannery is primarily home to mute swans, black swans do arrive and stay, with occasional breeding, as evidence in my image taken in 2006. I understand that black swans are native to Australia and New Zealand.

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.

Tuesday was the last of the very warm and dry days that saw the thermometer rise to 21.4C at 16.01 being 4.1C above my long-term average. It was the last of the consecutive dry days that also saw the UV value rise to 5.8, the highest this month and at the top end of the ‘High’ category. The cloud began to thicken late afternoon and considerably over night that gave us a very mild night with the thermometer not sinking below 10.8C being the second warmest this month and 3.8C above average.

Wednesday after dawn revealed a damp start to the new day, quite a contrast to previous sunny mornings under the anticyclone. A trough of low pressure passed our way during the early hours that brought the thick cloud and light rain and triggered the automatic rain gauge at 03.22. The rain was light and only amounted to 2.2mm, but very welcome for gardeners, after the numerous dry days. This was the wettest day since 22nd April.

A weather front will descend southwards over the UK today and maintain the cloudy conditions with possible sunny intervals this afternoon. With the current unstable atmosphere, there is the possibility of thunderstorms breaking out this afternoon.

The drier and sunny conditions will return for Thursday and Friday as a temporary ridge of high pressure exerts itself. However, by the weekend the weather pattern will become cooler and unsettled with rain likely at times as the Jet Stream is forecast to stream across the Atlantic direct to the UK bringing the changeable weather for the next few days.

Abbotsbury Swannery: Swans are one of the heaviest flying birds.

After a very overcast morning on Monday the sun broke through late afternoon producing welcome sunshine that lifted the temperature to 19.3C by 17.11, being exactly 2C above average. As on previous nights, the cool air stream and clear skies produced a very chilly night again that saw the thermometer very steadily fall away to reach a low of 3.2C at 05.24, just after sunrise in Marlborough at 05.02, being 3.9C below my long-term average. Thankfully, no cloud had drifted across from the North Sea in the early hours to spoil the sunrise.

Tuesday brought us a beautiful start to the new day without any cloud, clear blue skies, that saw the sun lift the temperature to 12.8C by 08.00. Later today we will see the first of the slow changes in our weather pattern after so many dry and warm days. The wind late afternoon is likely to back from the recent, persistent northeasterly, to north and northwest as the centre of the high relocates northwards allowing a very different day on Wednesday to creep in.

The anticyclone is still holding firm for the next three days but a small disturbance will bring us a more cloudy sky on Wednesday with the possibility of light showers, quantity unsure.

There is a major variation in the Spring rainfall this year compared to previous years. The total rainfall for the Spring 2025 season is just 18.5mm, that is up to today and including today, when the average over 41 years is 178mm. The previous ‘dry’ Spring was in 2011 with 65mm and the wettest was in 2000 with 279mm.

Sunshine will return on Thursday and Friday before the major change in our weather pattern arrives on Saturday, in time for the Bank Holiday!

Abbotsbury Swannery: Throughout June and July the swans moult when the feathers are then collected to make helmets for the Queen’s bodyguards. Lloyds of London also use quills from Abbotsbury swan feathers to register insurance losses in their ‘Doom’ book.

Although the maximum of 18.4C on Sunday, logged at 15.52, was above average (+1.1C) the overnight low of 6.2C, logged at 02.58, was below average (-0.8C). These statistics follow the pattern for recent days with the high just above average and the low just below average due to the sunny days and clearer skies initially overnight before the cool air and cloud arrives in the early hours. The low matched the arrival of the cloud when I looked at the cloud radar from just after midnight.

Once again the cool, cloudy air arrived around 03.00 early Monday having drifted in from the cool North Sea, picking up moisture on its travels. The forecast is for the cloud to take longer to clear today with brighter, sunnier weather towards midday although the temperature had recovered to 10.4C by 08.00.

The high pressure is still very much in charge although as the week progresses we will see more cloud, less sunshine and possible isolated showers by Wednesday as the barometric pressure slowly ebbs away. The pressure at 08.00 was very similar to yesterday at 1021.3mb. The Jet Steam shows signs of fragmenting and by Saturday arriving from the west rather looping north around the UK, which is likely to herald the arrival of weather systems from the Atlantic.

Abbotsbury Swannery: The swannery claims to be the only remaining managed colony of mute swans in the world and is privately owned. The Fleet lagoon is 8 miles long with the Swannery at its western end. The nests are constructed by the swineherd from the nearby reed beds.