THE Met Office has issued a flash weather warning for the East of England. Members of the public are being urged to prepare for heavy thundery showers, which will become widespread throughout the afternoon and continue into the evening. These may produce up to 20mm of rain in an hour in some places. Flash warnings of severe or extreme weather are issued when the Met Office has 80 per cent or greater confidence that severe weather is expected in the next few hours. The expected showers could make driving conditions hazardous and motorists are being warned to take extra care and seek advice from the Highways Agency on disruptions to motorways and trunk roads.