Category: Commentary

The numerous hours of sunshine on Saturday raised the temperature to 21.1C late afternoon at 16.59, however, out of the sun and in the brisk breeze it felt cool at times. It was the 15th dry day this month with another 4.3mm of equivalent rainfall lost through evaporation from ground sources and plant life. The forecast for the minimum temperature overnight was around 5C but to my surprise, on reading the data log this morning, I discovered that the thermometer had dropped very low to just 2.2C at 05.31, which was 4.8C below my long-term average. Looking back at the radar trace it clearly showed the thick, low cloud drifting in from the cold North Sea around 05.00, which ties in with the minimum shortly afterwards and the humidity increasing at that time.

Sunday after dawn revealed that the thin, low cloud had descended to form fog that limited visibility to around 300m. The visibility slowly began to recover shortly after 07.00 and by 08.00 had totally cleared. At that time the thermometer had risen significantly to 8.6C but the humidity was still high at 94.2%. As the sun’s strength builds and works on the cloud there is hope that today the cloud will thin and burn off as it retreats back towards the east coast giving us more warm, sunny weather.

The high pressure centre is beginning to move closer to Iceland though still dominating our weather for the next three days. However, it is the first sign that this week we will see a change in the weather pattern, with the first indications from Wednesday and more pronounced from Thursday onwards as the weather will become unsettled as the pressure drops further. After so many days with a persistent northeasterly, the wind will slowly change direction to north and probably northwest from Wednesday. The barometric pressure at 08.00 read 1021.7mb, down 4mb from its high last Thursday.

Abbotsbury Swannery: The swans are based in the western end of the Fleet lagoon, which is the largest lagoon in England. At the height of the season there are 800 to 900 swans, which the swineherd feeds twice a day. The lagoon is open to the sea at its eastern end so the salinity of the water decreases further west, where the swans are based. The Benedictine monks didn’t eat meat but the occasional cygnet was consumed that ate the eelgrass, which gave a fishy taste and was acceptable!

The sun’s return for much of the day on Friday was very welcome and meant an above average temperature with a maximum of 21.1C logged at 17.13 being +3.8C, after the cool, cloudy day on Thursday. The dry spell continued with the equivalent of another 5mm of rainfall lost through evaporation from ground sources and plant life. The dominant anticyclone meant a continuation of the brisk, cool northeasterly breeze, a price to pay for the dry, sunny weather that we have enjoyed for so many days, with the high pressure resident in its current position.

Back tracking the cloud radar this morning it was noticeable that the cloud began to drift back across our area, from the North Sea, shortly after midnight, which corresponds with the minimum temperature occurring in the very early hours, rather than much later, around sunrise recently, when a minimum of 8.2C was logged at 01.25, thus a much milder night not being under many hours of clear skies. It was the mildest night since the 12th being 1.1C above my long-term average.

The start to Saturday revealed the total cloud cover that was relatively thin and high. The cloud radar showed the cloud drifting as far west as Devon in the early hours and just beginning to thin over Plymouth at 08.00. At that time there was evidence of some brightness here, so we should get some warm sunshine by midmorning or earlier, as the cloud thins and disperses, retreating back eastwards. The air flow starts around the north of Iceland, drifts down the west coast of Scandinavia and then bends west across the UK. That is a long track across cool water picking up moisture as it travels.

There is increasing confidence in the projected Jet Steam track, which is forecast to begin to fragment and change its direction, probably from as early as Thursday next week. Therefore, by Friday there is likely to be a significant change in our weather after the many consecutive dry and sunny days, with the possibility of some precipitation.

Thankfully, the problem with the restricted width of the data pages on this website has been resolved so they are now full width on each page.

Abbotsbury Swannery image: I mentioned yesterday that the early monks farmed the swans to produce food for their lavish banquets, however, I heard this morning on a Radio 4 programme, in a conversation with the Swan Keeper, that they only ate the tender cygnets. There was also the factor that Swans drank the brackish water whereas the cygnets only drank the fresh water and ate eel grass, so presumably much more to their taste.

Surprisingly, Thursday did not see the cloud begin to thin and break as forecast. The cloud that had drifted in from the North Sea overnight persisted all day and in fact eased even further westwards as the day progressed. As a result the temperatures by day and night were depressed making it feel chilly in the brisk northeasterly breeze. The maximum of 15.4C was 1.9C below my long-term average making it the coolest day since the 6th. There were occasional glimpses of very brief bursts of sunshine when the cloud thinned. But overnight the cloud did disperse so that we had another cool night that saw the thermometer drop away to 5.2C at 05.34, just after sunrise at 05.14, being 1.8C below average.

Friday brought us the return of welcome sunshine after sunrise that had lifted the temperature to 11.3C by 08.00. After 07.30 small areas of light, high cloud did drift across from the North Sea, on the continuing brisk northeasterly breeze, but minimal interruption of sunshine.

The anticyclone, centred just to the north of Scotland, continues to push down south over the Uk and across France and built further, an increase of another 2mb since yesterday, with a barometric pressure reading of 1027.4mb at 08.00 making it the highest pressure all month and since 10th April. The forecast charts indicate that this high pressure will keep the dry, sunny weather well into next week.

Unfortunately, I hadn’t realised that when the website was rebuilt at the end of last year it had inadvertently restricted the width of the data sheets, making viewing less than ideal. This situation, hopefully, will be addressed soon, not something I can remedy, I just fill in the spaces!

There will be a new image each day from the Abbotsbury Swannery, that will continue into next week. The Swannery was established by Benedictine Monks who built a monastery at Abbotsbury during the 1040s. The monks farmed the swans to produce food for their lavish Dorset banquets.

The many hours of strong sunshine on Wednesday lifted the temperature to 22.1C by 15.35 being 4.8C above average. The wind continued brisk and from the northeast peaking at 15mph. Much comment has been made about the continuing dry spell, which was compounded yesterday as the equivalent loss of rainfall from evaporation from ground sources and plant life reached 5.0mm, the highest loss since 20th June, inflated yesterday due to the little residual moisture from the minimal rainfall of 0.5mm that fell on the previous day. Once again the past night was chilly that saw the thermometer reach a low of 5.9C at 04.19, which was again below average of -2.1C, before cloud drifted across again from the North Sea.

Thursday revealed total cloud cover. Backtracking the cloud radar it was clear to see that thick cloud had drifted across from the cold North Sea, current sea temperature is 11C, arriving just after 04.00 that linked with the minimum temperature logged at at 04.19. The moist, cool air , not having been heated by early sunshine gave a humidity reading of 83.3% at 08.00. This cloud bank will, hopefully, thin and break up as the sun gathers strength during the morning. The thermometer had risen a little to 8.0C by 8.00, making it the coolest start to a new day for a week at that time, especially as wind chill was also factor making it feel only 7.0C outside.

The dominant high pressure will stay centred just to the north Scotland and push further south, there has been a further rise of 3mb since yesterday. The projection of the Jet Stream track indicates that this situation will continue into next week. The wind track shows it currently originating just east of Iceland, then travelling south down across western Scandinavia before crossing the North Sea, thus a very cool air stream.

A selection of images from Abbotsbury Swannery will be added each day, which is the only place in the world where people are able to walk through the heart of a colony of 600 nesting Mute Swans. The site is on the south coast, just east of Weymouth.

Unfortunately, I hadn’t realised that when the website was rebuilt at the end of last year it had inadvertently restricted the width of the data sheets, making viewing less than ideal. This situation, hopefully, will be addressed soon, not something I can remedy, I just fill in the spaces!

Rain to the north and rain to the south of Marlborough over the past two days but barely a drop over our area, just 0.5mm, which very quickly dried up, that took the monthly rainfall total to 1.1mm when the 41-year average is 60.4mm. The thunderstorms were observed forming at 13.30, just to the south of area and then continued to build from Kent to Wales with the main storms travelling just south of Marlborough. As the air temperature increased during the latter part of the morning the air began to rise and in the unstable atmosphere where air from the depression and that from the North Sea met, began to condense, cooling as the gained height, then formed the storms. However, the warm sunshine continued during the morning and early afternoon with a maximum of 22.7C at 14.50 before the clouds thickened and rain spots were observed at 14.10, when I was out walking, but not measurable, and a very, very brief thundery shower at 15.55. The high was 5.4C above my long-term average. The past night was again chilly that saw the thermometer very slowly fall away to reach a minimum of 5.7C at 02.27, much earlier in the morning than has been recently been the case when nearer sunrise. This low was 1.3C below my long-term average.

Wednesday brought us another glorious start to the day with splendid sunshine and not a cloud in sight. This resulted in the thermometer climbing to 11.2C by 08.00. As the anticyclone slowly relocates it has meant the wind direction backing into the northeast today and brisk.

As mentioned in the report of previous days, the recent low pressure system has migrated back into the Atlantic and is currently still filling and by tomorrow will have disappeared. The high pressure has continued to build, up another 4mb since yesterday reading 1021.4mb at 08.00, and extended further southwards across the UK.

The main Jet Stream, having travelled across the Atlantic, continues to loop northwards around the UK and then back southwards towards the Continent. This the pattern is referred to as an “Omega’ block as it resembles the Greek letter for Omega. It is in fact a blocking high pressure that is keeping any weather fronts and weather systems from advancing towards the UK from the Atlantic. The forecast charts indicate that this situation will continue into next week so we have a number of dry, sunny and warm days ahead.

The images for the next week or so were taken at the Abbotsbury Swannery near Weymouth in 2006 that is home to over 600 mute swans. This time of year is perfect to visit and see the many hundreds of fluffy signets starting their new lives. Tomorrow I will post one of the images with an ah!!factor.