Isolated heavy, and possibly severe thunderstorms are expected to develop during Wednesday afternoon across parts of Northern England and Southern Scotland. Some torrential downpours are possible leading to localised surface water flooding, with large hail, squally winds and frequent lightning also possible hazards.
The public should be aware that there is a chance of some very localised significant disruption.A hot and increasingly humid airmass now lies across much of the UK. This airmass is conducive to isolated thunderstorm development during the afternoon and into the evening. With large amounts of energy available in the atmosphere, storms could be severe, with torrential downpours, gusts to 50 mph and large hail of around 1cm in diameter. 20-30 mm of rain is possible in an hour, with as much as 40 to 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 and stay 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/