Another night with a dramatic change in temperature

Sunday brought after midday 5.7 hours of sunshine but the light breeze from the north meant the temperature was depressed with a maximum of only 6.1C being 4.4C below average. The UV level of 2.3 was the highest since 11th October being at the top end of ‘Low’.

During the late afternoon the thermometer began to fall again under clearing skies but fell rapidly during the evening. The air reached freezing point (-0.1C) at 19.36, -1.0C occurred at 20.05 and -3.0 at 22.54 before the minimum of -3.3C was logged at 23.30. Thereafter, the thermometer began to recover so that by 08.00 on Monday the temperature had returned above freezing with a reading of 0.7C with no evidence that during the late evening a hard frost had occurred. The thermometer edged above freezing at 03.15 before briefly falling back to -0.1c just before dawn.

Monday after dawn saw complete cloud cover. The anticyclone has been retreating with the current pressure at 08.00 of 1025.8mb, down 10mb in 24 hours. The centre of the high pressure is now over the western side of the Bay of Biscay that will bring air movement today from the west – a significant change in direction.

‘Scandinavian Surge’ continues cold weather

Although the maximum on Saturday was 1C up on Friday, which was 1C up on Thursday, it was a cold day. The thermometer eventually rose to a peak of 6.4C, which was 4C below the 37-year average. I read yesterday that the plunge of cold air from this direction is referred to as the Scandinavian Surge. The breeze continued from a northeasterly direction but less brisk than of late with a peak gust of 13mph.

The past night was very similar to the previous night in that the thermometer dropped away to a minimum in the early hours before rising again as cloud drifted in. The minimum of -1.3C at 02.27 Sunday morning produced a short lived air frost so that by 08.00 on Sunday the thermometer had recovered to read 1.2C.

Sadly no sun was evident after sunrise on Sunday due to the thick cloud. The wind, has backed slightly into a more northerly aspect as the centre of the anticyclone is over the southwest coast of Ireland at midday. The air today is much drier than of late with the wind now passing over more land than sea with a humidity of 72% at 08.00, not seen since 12th February.

Limited sunshine on Friday – disappointing!

Although Friday started with glorious sunshine, cloud built up quickly obscuring the sun after 1.1 hours. The breeze continued mainly from the north east and brisk, peak gust of 19mph, that limited the temperature rise to a maximum 5.5C. This was 1C up on the Thursday very low figure but still a significant 5C below the average.

It was dry day with the UV level restricted due to cloud, with a peak reading of 1.8, which is classed as ‘Low”. The UV needs to reach 3 before it is classed as moderate.

The thermometer steadily dropped during the evening reaching a minimum of -2.0C at 02.45 on Saturday morning, which was 4.4C below the 37-year average.

Saturday dawned with cloud on the eastern horizon blocking out the sun but just before 08.00 it rose above the cloud but sadly more continuous cloud cover shortly obscured much sunshine after 08.45. The thermometer had recovered to 1.1C at 08.00. The high pressure is meandering around the UK and its centre is forecast to be over The Wash at midday hence the very high current pressure of 1035.6mb, the highest since 27th February.

Sunshine at sunrise – what a treat!

Thursday continued the gloomy, grey and sunless days. The cold air brought on the brisk north-east breeze, gusting to 21mph at times, meant a cool day with wind chill. The thermometer was reluctant to rise during the daytime with a maximum of only 4.4C, which was almost 4C on the previous day. This was an increase of only 1C after the 08.00 reading and 6C below the 37-year average.

There was a drop of just 3C overnight with a minimum of 1.3C at 06.54 on Friday morning being 1.1C below the long-term average.

It was such treat to enjoy sunshine as the sun rose above the horizon on Friday followed by broken sunshine as the morning progressed.

The high pressure is currently centred over Edinburgh, having moved southeastward over past hours. This has resulted in the barometric pressure rising several millibars since yesterday with a reading of 1031.7mb at 08.00. As a result the wind has backed a little, currently coming from the north north-east. The modest breeze is again producing a wind chill so that it felt more like 2C outside at 08.00 rather than the 3.2C indicated on the sheltered thermometer.

The variation between the maximum and minimum temperature over the past twenty-four hours, referred to as the diurnal range, was a minimal 3.1C.

First rain in a week

Wednesday was the first sunless day since 19th February as the grey, gloomy weather persisted all day. The thermometer struggled to reach 8.3C, which was 2.2C below the 37-year average.

A few rain drops were observed at 13.21, not enough to wet the pavement, as a large shower complex moved northwards just to the east of this area and another more modest shower area to the west. However more persistent light rain began just after 21.15 and a heavier shower at 04.00 on Thursday. These showers amounted to 3.1mm of rainfall, the first this month and since 24th February.

The fog returned late evening and was thick but by first light on Thursday the cloud base had risen so that visibility had increased to at least 2,000m if a little misty. The minimum temperature of 3.0C was 0.6C above the long-term average thanks to the thick cloud acting as a duvet stopping warmth from escaping into the atmosphere. The wind today has backed from easterly to northeasterly as high-pressure develops to the north west of the UK bringing much colder air, and very light again. The maximum gust on Wednesday was just 14mph.