Category: Commentary

A maximum of 13.6C on Thursday was again below average at -0.5C as the high pressure to the west of the UK continued to feed cold air down from the north arriving on a brisk westerly gusting to 20mph at its strongest. The cloud overnight acted as a duvet limiting the loss of warmth to the atmosphere thus producing a minimum of 8.1C, which was 4.4C above my 40-year average.

Thursday brought the strongest sunshine in strength (w/m2) since 15th August and the highest UV since 3rd September registering 5.6, which was well into the ‘High’ category. It was also the third continuous dry day. The monthly rainfall total is 41.4mm being 73% of my 40-year average.

Friday revealed weak intermittent sunshine after dawn but predominantly cloudy.The wind is still cool and brisk with a more northerly component than on Thursday, so another cool and probably mainly cloudy day. The wind will slowly veer into the northeast as the day progresses, a direction not occurring since March. The cold air is originating north of Iceland and is streaming down the North Sea.

The anticyclone is still centred to the west of the UK although edging closer and likely to dominate our weather for the next few days.

The barometric pressure has continued to rise slowly as the anticyclone to the west of the UK edges closer. As a result, on Wednesday we had another dry day although the maximum of 12.3C, being 1.8C below my 40-year average, was disappointing due to the continuing brisk wind, maximum gust if 20mph, from the north and northwest. That colder air stream also meant a chilly night under clear skies, with the thermometer sinking to 2.0C at 04.45 producing a short lived ground frost. The low was 1.7C below my long-term average.

The sun began to shine strongly on Thursday shortly after it got up and lifted the temperature to 5.4C by 08.00. Mid-afternoon a weather front will cross our area bringing with it cloud thus obscuring the sunshine after a sunny morning.

The high pressure has seen another 6mb aded to the barometric pressure since Wednesday and will continue to rise as the anticyclone edges closer and is likely to take charge of our weather for the next few days. That should mean a few dry days but the cloud cover variable. The wind will back a few degrees early afternoon and come from the west, a slightly warmer direction than of late.

The thermometer did rise a little higher on Tuesday, following the cold day on Monday, with a maximum of 13.7C, but still below my 40-year average at -0.4C. However, it was a dry day with ‘Moderate’ UV levels at the peak.

With clearer skies overnight the thermometer fell steadily to reach a low of 2.1C at 03.00, also below average at -1.6C, making it the coldest night this month and since 16th March. However, there was a modest rise after that time to reach 6.6C at 08.00.

The anticyclone to the west is beginning to influence our weather and will do so for the next few days. The barometric pressure has risen 12mb in two days with a reading of 1018.1mb at 08.00. However, it will continue to stream cold air from the northwest, and probably north tomorrow, so no return to the warm days that we enjoyed almost two weeks ago. As the centre of the anticyclone approaches, the wind strength will continue to fall after the gusty days of late.

With a maximum of just 11.3C on Monday it was the coolest day since 28th March being 2.8C below my 40-year average. It felt up to 2.5C colder outside in the very strong northwesterly wind that produced a wind chill, often gusting in excess of 30 mph with a peak gust of 39mph. There were the occasional brief rain squalls that amounted to 2.6mm of precipitation with small hail falling at 14.40. At that time the air temperature dropped from 10.4C to 8C.

The past night saw an above average minimum if 6.8C at 06.39 early Tuesday being 3.1C above the long-term average.

There was the odd flicker of brightness early Tuesday with longer spells of sunshine just before 08.00 that had lifted the temperature to 9.1C by 08.00.

The recent depression is now heading eastwards over Germany and we are coming under the influence of a high pressure in the Atlantic. The barometric pressure at 08.00 read 1014.1mb, up 8mb since Monday. The anticlockwise circulation of air associated with the depression and the clockwise circulation linked to the anticyclone is still streaming strong winds from a northwesterly direction, but not as strong as on Monday. This will continue into Wednesday.

The brisk westerly on Sunday allowed some sunshine in the cloud breaks, but it was a much cooler day than previously. The maximum of 13.3C was 0.8C below my 40-year average. The low of 6.8C was above average at +3.1C, and occurred just after midnight at 01.03. This was the turning point in the wind strength as after that time it began to increase in strength and stir up the atmosphere thus minimising the heat loss. The maximum gust of wind until around 04.00 was just 14mph but reached a peak of 25mph at 07.35 and forecast to increase further.

The distinct change in our weather is due to the depression, that has been centred around Iceland recently, moving down across the country today. The barometric pressure as a result is falling rapidly, down 19mb since Sunday and reading 1006.3mb at 08.00, a drop of 23mb since Friday. The relocation of the depression will also mean that the wind will veer from the west into the west-northwest or even northwest briefly today.

Monday dawned with intermittent spits and spots of rain observed at 06.00 and later. The rain radar indicates that the main rain band will arrive nearer 08.40.

The recent three dry days has seen the rate of evaporation from the ground and plant life exceed 2mm a day as the sun and breeze got to work with no rain.