Barometer falling rapidly ahead of storm

With little sunshine, just 1 hour, and a brisk wind from the southwest on Friday it was not surprising that the peak temperature of 13.1C was again below average (-1.5C). There was brief rain around 10.00 that amounted to 0.5mm but the remaining part of the day and night were dry.

During the evening the thermometer fell steadily away to reach a minimum of 5.3C at 00.10 early on Saturday being 1.8C below average. The temperature then began to climb again as cloud built up ahead of the next rain band.

Three depressions on Friday in the North Atlantic have now combined to form a deep low pressure system to the north west of Scotland that produced the thicker cloud and an increasing wind speed from 03.00 on Saturday morning. Light drizzle was observed at 07.45 with a gust of 21mph. By 08.00 the temperature had risen to 10.9C. The barometric pressure is now falling rapidly with a current reading of 1003.5mb whereas the centre of the depression had a reading of 953mb at 08.00. This considerable variation in pressure is producing a steep pressure gradient that will see the wind strength increasing considerably during Saturday. The rain radar shows a wide band of heavy rain approaching the West Country that will reach us in a few hours.