Light breeze from all points of the compass on Thursday

Thursday was a very calm day with little wind and sometimes the anemometer was becalmed. However, I did log a breeze from the southeast, east, north, west and southwest, and not in that order, as the direction was variable.

It was a dry day with the thermometer rising to 22.3C being just below the July average. There were 7.3 hours of welcome sunshine and the UV level, at its peak, rose to Very High.

Overnight was very still and mild with the thermometer not falling below 13.6C, which was 1.8C above the average.

Friday arrived with misty conditions and total cloud cover.

June 2021 Review

The month began with Continental Air across the country and considerable heat with a maximum of 27.3C on the 2nd. However, all changed on the 3rd as the cooler more moist Atlantic Air replaced the hot, warm air dropping the maximum temperature by around 8C.

By the 5th barometric pressure had risen thanks to an anticyclone that was close by for many subsequent days raising the thermometer to 27.9C on the 13th. This was the hottest day since 11th and 12th August when the thermometer peaked at 34.1C.

By the 13th the minimal rainfall of 0.7mm contrasted with the equivalent loss of 45mm of rainfall through evaporation from ground sources and plant life in the hot dry period.

The anticyclone relocated bringing very warm and dry air that saw the thermometer rise to its highest this month with a maximum of 27.9C on the 13th. The following three days peaked just over 26C.

The hoped for steady rain from storms crossing the English Channel overnight on the 16th did not materialise as just 0.2mm fell when considerable quantities fell to the east of the area. This mimicked the weather pattern on the 6th when only 0.5mm fell whilst copious quantities (30mm+) fell to the east of Marlborough. I have noticed this feature on a number of previous occasions. On the 2nd the storms aimed for Central England but when they reached the Marlborough area the rain radar showed the cloud thinning and the bulk of the rain passing to the west and east of Marlborough, once again a feature I have also noticed on previous occasions.

The 17th saw a breakdown in the weather as the first substantial rain for June fell with a depression close by. Subsequent days saw temperatures plummet as a northeasterly breeze set in with maxima some 10C below the previous days. Just 13.2C was logged on the 18th when 27.9C was reached on the 13th, that being the hottest day in June. The minimum of 10.4C felt more like 9.2C outside on the 21st as the northeasterly had strengthened producing wind-chill.

This wet period brought a very wet day with 10.2mm on the 18th although intense storms passed to the east and west of the area so gardeners welcomed light to moderate rainfall.

There were four consecutive sunless days from the 18th to 21st. The evaporation from the ground and plant life on the hottest days saw the equivalent of almost 5mm of daily rainfall lost to the atmosphere, which dropped to 0.7mm on the wet, cool and sunless days.

The month ended with variable weather, often overcast, thanks to a depression that was reluctant to move from northern France that threw several weather fronts across the area. This included the very wet day on the 27th with a daily rainfall total of 16.1mm being the wettest day since 7th may (16.5mm).

The monthly rainfall totalled 46.4mm being exactly 8mm below the 37-year average. That contrasted starkly with numerous areas in the country that received excessive amounts of heavy rainfall and totals well above average. There were 19 dry days with a run of 9 consecutive dry days from the 7th to the 15th.

The exceptional years of rainfall since this station started in 1984 were just 5.3mm in the very dry June of 2018 and 143.2mm in 1998. The January to June total rainfall total was 25mm below the 37-year average.

Evaporation from ground sources and plant life was 83.8mm of equivalent rainfall, which was 88% of the average over the past 12 years.

Thanks to the very hot period around the middle of the month, and warmer nights due to frequent cloud cover, the mean temperature was 1.2C above the 37-year average. The mean temperature for June has shown a slowly rising trend since 1995, mainly due to less cold nights.
The Meteorological Office recently posted that they are “Searching for the next round of names ahead of the next storm season, and the UK public are once again being asked for their input.
In partnership with Met Éireann and KNMI, the forecasting services for Ireland and the Netherlands respectively, the group has been naming storms together in recent years in order to help the media and the public communicate more effectively about the impacts of severe weather events.
As part of the naming process, each of the three meteorological organisations get to name selected letters in the alphabet, reflecting the diversity of the three countries naming the storms. Names are selected for each letter of the alphabet, except for Q, U, X, Y and Z, in keeping with storm naming conventions.
This year, the Met Office is asking people in the UK to submit their suggestions for consideration via its website. People can submit as many suggestions as they choose and also have the option of adding a reason for their suggestion to help it in consideration. The Met Office will then choose from some of the most popular names suggested. “
For most people, not knowing what the weather is going to do in the next hour is a minor inconvenience. But when it comes to the power network, not knowing what the weather will do next isn’t just an annoyance, it’s a significant source of carbon emission.

On a sunny spring day in Great Britain, solar power can account for about 30 per cent of all the electricity being produced on our island. Solar panels perform best on cool but sunny days. Under ideal conditions solar panels might churn out 9 gigawatts, a huge chunk of the 30GW of average demand, but if a big cloud swoops down over the southwest, where many of Great Britain’s solar farms are situated, a significant portion of that renewable energy suddenly disappears – the equivalent of an entire gas power station instantly going offline.

Very, hot sunny weather that builds throughout the day does not necessarily produce more photovoltaic power as the solar panels lose efficiency above 25C, which is the test temperature for new panels. Being dark coloured the panels tend to get hotter then the ambient air by 2 to 3C. The panels work more efficiently in winter with lower air temperatures but of course that sun is not so strong and much reduced in hours. Panels also lose efficiency over time and the rule of thumb is up to 2% per annum.

One way to get around this is to get better at forecasting the weather. If we knew exactly how much solar power Great Britain was likely to produce at any one moment, the Electricity System Operator (ESO) could dial back the amount of power it holds in reserve, bringing down the total carbon footprint of the energy grid. Research that could provide better solar forecasts in the UK could save 100,000 tonnes of carbon dioxide from being emitted each year. The idea is to use ‘machine learning’ to improve what is known as solar “nowcasting” predicting solar electricity generation less than a few hours in advance.

Rather than working out what the weather will generally be like in a given area, to get really precise solar forecasts, they need to know precisely where each cloud will be located relative to a solar array and how the size and shape of the clouds influence how much sunlight gets through to the panels. However, information about the installations is spread across several database and other crucial bits of data are missing altogether. In an ideal world we’d know the locations and capacity of all the solar across the country and better still the orientation and tilt of major installations.

A little research revealed that there were 51 solar farms in Cornwall with 32 under construction or approved. The largest solar farm in the west is situated in Dorset providing electricity for 60,000 homes. With more than 700 UK battery projects either planned, being built or in operation, we are set to see huge build up of the storage needed to make the most of Britain’s world-beating renewable resources.