Windrush Weather

Thursday was the sixth successive day with thick, low cloud that meant no UV light triggered the sensor. Like previous days the temperature varied little between night and day with the diurnal range just 1.1C. The maximum of 6.5C was logged at 19.26, being 1.6C below average and the minimum of 5.4C at 07.48 early Friday, being 2.0C above the long-term average. The precipitation amounted to 0.9mm from mist and light drizzle early Friday. The thermometer edged upwards just after 17.00 as a warm front arrived that raised the temperature 0.5C to its peak of 6.5C. Just after 01.30 early Friday the temperature started to ease downwards again. There was one significant change compared to previous days in that there was almost a complete absence of wind, with the anemometer occasionally coming alive indicating 1mph or 2mph for many hours, the peak movement was just 8mph.

Friday started even duller than previous days, if that was possible, as the cloud was even lower and thicker from a wide band of mist and light drizzle extending from London, west to North Devon. The cloud draped the Marlborough Downs and Savernake Forest with continuous light drizzle in the misty conditions.

The recent high pressure has been easing away dropping 6mb in the last twenty-four hours. As a result of that repositioning the wind will at last veer from the northwest that was persistent for the past four days to southeast and south with it moving future clockwise to southwest this evening, bringing a less cold flow of air. We will have to wait until Sunday for temperatures by day returning closer to normal.

Wednesday was like the previous days trapped under the persistent low, thick cloud brought in by the northeasterly breeze but thankfully less strong. However, wind chill was still a factor when going out as it felt at least 2C lower than that indicated on the thermometer. No rain or drizzle was observed and no UV light triggered the sensor being the fourth consecutive day that this has occurred, but not surprising in Winter under the thick, low cloud.

The diurnal temperature range was minimal at just 1.0C variation between the day maximum of 5.6C at 15.25 and the night minimum of 4.6 at 01.24 early Wednesday. The high was 2.5C beak average whilst the low was 2.2C above average.

Thursday morning was identical to previous days so no change in the cloud cover but the wind continued much lighter and from the northeast with reduced wind chill.

The anticyclone that has hovered over the UK for the last few days is showing signs of migrating eastwards but change in our weather will be slow and not much improvement until the weekend. The barometric pressure has varied just 1mb since Monday with the reading of 1032.6mb at 08.00 with the centre of the anticyclone almost overhead this morning.

As the anticyclone moves away the wind tomorrow will begin to back into the east then southeast thus stopping the flow of air travelling over the cold North Sea and picking up moisture on its way. This will mean the resultant persistent gloomy conditions should improve.

The very high pressure moved little on Tuesday so it was another dull day, however, the wind strength had dropped a little with a maximum gust of 24mph and the average wind speed over ten minutes had fallen into single figures after the peak average go 18mpg on Sunday. Once again, due to the brisk wind from the northeast, a cold direction, the thermometer struggled to rise just 1.1C all day with a maximum of 6.3C at 13.38, being 1.8C below the average. At night the thick cloud acted as a duvet limiting any loss of warmth into the atmosphere with a drop of only 1.6C to a minimum of 4.7C at 07.16 early Wednesday, which was 2.2C above the average. Needed to say any UV light was not strong enough to trigger the UV sensor.

The new day on Wednesday struggled to come into life under thick cloud cover and the northeasterly still blowing but not as strong. Outside due to wind chill it felt more like 2.1C at 08.00 when the thermometer read 4.7C. The air is much drier today with a humidity level of 86% at 08.00 so no drizzle currently falling. There is no indication on the rain radar of any drizzle carrying cloud arriving at the moment.

The anticyclone has moved very little so continues the air stream from the northeast but today the ten minute average wind speed is down to 5mph with a maximum gust of just 13mph during the past two hours.The barometric pressure has varied little with a reading of 1033.3mb at 08.00, down just 0.4mb in twenty-four hours.

The forecast track of the Jet Stream varies little over the next two or three days so what we have today will be similar to that on Thursday and Friday but hopefully perhaps with a few breaks to brighten each day.

Although the worst of the very strong winds have passed there were gusts up to 27mph on Monday and the average wind speed over ten minute hovered around 12mph all day. The extreme gusts and lulls of Friday and Saturday have been superseded by more consistent winds without the extreme gusts. As a result of the cool northeasterly wind and thick cloud cover over the twenty-four hours, the temperature varied little by day or night with a maximum of 6.6C being 1.4C below average and a minimum 5.2C being 2.7C above average. Light drizzle over various periods amounted to 0.3mm.

Tuesday began where Monday ceased with very thick, low cloud and a persistent wind from the northeast. The pressure differential between the low and high pressure systems has been falling as a result the wind is very slowly beginning to drop with the average wind speed over ten minutes now down to 8mph from a high of 18mph on Sunday.

The cool, strong wind is once again producing a wind chill so that the temperature of 5.2C at 08.00 outside felt more like 2C. Also the word having travelled over the North Sea is continuing to pick up moisture so although it is not likely to rain there will be variable drizzle from time to time.

The high pressure system has edged a little closer, as a result the barometric pressure read 1033.7mb at 08.00, the highest for a month.

Although the extreme winds gusting to over 40mph abated a little Sunday evening they were still strong at over 30mph. The strong wind and from a cold northerly direction meant a cool day with the thermometer not exceeding 6.9C at 22.35 being 1.2C below my long-term average. In fact those conditions produced a wind chill again in that when the thermometer read 6.1C in the evening the wind chill meant outside it felt more like 2C. The minimum of 4.9C was logged at 14.30 being 2.5C above average. The intermittent showers amounted to 3.8mm.

Monday revealed a day that was so similar to Sunday with the wind still gusting strong. However, there was one major variation. The very strong gusts, then brief lulls, on Sunday had given an average speed over ten minutes of up to 18mph whereas on Monday the very strong gusts had dropped away with gusts up to 25mph with more consistent wind strength around 15mph and still an average speed over ten minutes of 14mph.

The winds are the result of a squeeze between the high pressure centred off Ireland, circulating clockwise as they do, and the old depression now over the Mediterranean, circulating anticlockwise. The barometric pressure has risen another 12mb with a reading of 1032.2mb at 08.00, the highest pressure since 14th November.

There is a lot of cloud again due to the airstream travelling over the North Sea picking up moisture along the way.