The two cold fronts passed over our area on Sunday as forecast, just before and after midday, that brought thicker cloud and a cooler air stream on the breeze from the west. The maximum of 15.1C was the coolest day since the 9th but still 1.0C above my long-term average. The cloud meant lower solar energy and the UV level back to the ‘Low’ category, not seen since March, likewise we have not seen a westerly since last month. Variable cloud meant the thermometer did not begin to drop away until after 23.20 due to a bank of cloud, but by 04.52 the thermometer had reached its minimum of 1.5C being 2.2C below average.
First light on Monday revealed the low temperature and a much more moist air stream, a humidity of 95% was the highest at 08.00 all month, which had allowed fog to form that at sunrise limited visibility to 300m. However, just before 07.30 the sun began to break through and by 07.50 it had virtually dispersed, just limited to the north of our area and could be seen in the distance over the Thames Valley.
We are now under low pressure systems to the northwest and southwest of the UK. The small low currently over Iberia will migrate northeastwards over France and is forecast to be over southern England this time tomorrow bringing more cloud and the possibility of light rain, there is some disagreement over this feature between the major forecasters. The barometric pressure had dropped to its lowest all month yesterday due to the departure of the anticyclone and arrival of low pressure systems with a reading of 1003.2mb, but eased upwards to day to read 1006.0mb.
The cooler air and reduced sunshine is slowing up the development of the apple blossom but slowly the trees are beginning to change colour.