Saturday 28th February
The area of low cloud persisted over southern England for much of Friday morning, the air was saturated. At 08.00 the humidity was 96.1% whilst the temperature read 10.3 and the Dew Point 9.7C. The Dew Point temperature is the temperature when the air cannot hold any more moisture. There was a period mid-morning when very light rain and drizzle was observed and seen on the radar over the Marlborough area. I suspect that the saturated air stream was lifted higher as it arrived over the Marlborough Downs and that slight drop in temperature, because air cools when it rises into the atmosphere, meant that the air stream couldn’t hold any more moisture.

The maximum of 13.0C at 15.17 was due to the cloud thinning and some brightness breaking through, being 4.7C above average. The temperature fell steadily away during the late afternoon and evening until reaching a low 5.8C at 05.39 early Saturday, being 3.9C above average. It was the coolest night since the 21st.

Saturday arrived with total cloud cover from the hang back of cloud from the departing weather front. The minor ridge of higher pressure, not high pressure, should see the day improve as the cloud thins and, hopefully, the sun arrives, which it didn’t yesterday. The barometric pressure began to rise just after 02.00, and is rising rapidly this morning, but will be short lived as cloud and rain will arrive this evening as the pressure falls again.

Looking ahead, Sunday and Monday are likely to be dominated by low-pressure in the eastern Atlantic, however by Tuesday there are signs that high pressure over the Continent will edge westwards across the UK that should see drier and brighter weather arrive. The projected track of the jet stream edges north of the UK during this period, allowing this extension of the anticyclone and being on the warmer, south side.