Sunday 27th September
Saturday was a splendid early autumn sunny day that eventually saw the thermometer climb to a peak of 20.6C at 15.14 before cloud began to thicken around 16.00. It was the seventh consecutive dry day with the UV level classed as Moderate. The cloud again began to thicken considerably after 22.00 that meant a less cold night than previously, however, a minimum of 8.6C, logged at 05.18, was 0.9C below my long-term record.
A thick bank of cloud blotted out any chance of sunshine after dawn on Sunday. In fact, two weather fronts are going to pass over the UK today, both cold fronts with cooler air behind them, that will see the cloud thicken towards mid-day, after some brightness mid-morning, with the possibility of light shower activity from around noon. The rain radar at 08.00 indicated scattered showers already falling over Dartmoor and Exmoor arriving from the southwest, while there track indicates that they will miss us. However, a line of developing shower activity, stretching from Brittany across the Channel towards southern England, is now being shown on the radar that could pass over our area. This significant change in our weather is the result of low pressure to the west of the UK that is producing very heavy rain over Ireland and North Wales. The air stream today will veer from southeast to south then west-southwest as the day progresses and pick up in strength after a calm night.
We are now in an unsettled period of weather as the recent high pressure has moved over eastern Europe allowing low pressure systems to arrive from the Atlantic that will edge towards the UK. The barometric pressure is currently falling rapidly with a reading of 1015.0mb at 08.00.
Tomorrow will see another major change in wind direction, from west, through north to east that will give us a sunny day behind the departing Sunday weather fronts. As Tuesday progresses, the wind direction will change further, to come the south-southeast, that will mean a much warmer air stream arriving from the near Continent, resulting in the temperature climbing higher again, probably several degrees above the late September average.
By Wednesday a very deep depression in the Atlantic, will have edged closer, its centre heading between Scotland and Iceland, that will bring possible sunshine and shower activity. At the moment the forecast charts indicate that the large area of high pressure over central Europe will block any further movement of the depression over the UK, thus any heavy rain and strong winds will keep to the west of England.