Isolated heavy, and possibly severe, thunderstorms are expected to develop on Friday evening across parts of England and Wales. These are likely to become more frequent later and spread northwards towards southern Scotland. Some torrential downpours are possible leading to localised surface water flooding, with large hail and frequent lightning also possible hazards.
The public should be aware that there is a chance of some very localised significant disruptionOn Friday evening another hot and increasingly humid airmass is expected to spread into the south from the Continent. This airmass looks conducive to the development of isolated thunderstorms during the evening across England and Wales which could become more frequent later in the night as they spread northwards towards Scotland. With large amounts of energy again available in this atmosphere storms could be severe, with torrential downpours and large hail. 30 mm of rain is possible in less than an hour, with as much as 50 mm possible in 3 hours very locally.
Large uncertainty remains regarding areas most at risk from storms, and many areas will miss these altogether, staying largely dry. However, where they do develop, disruption is possible. The public is advised to take extra care, further information and advice can be found here: http://www.metoffice.gov.uk/public/weather/warnings/