Met Office weather forecasters say thunderstorms are on the cards on Saturday morning following the heatwave this week which brought the hottest day of the year so far As many as 17 UK areas could finally see some proper downpours as rain maps turn yellow. Key points and original sources are listed below.

• Met Office weather forecasters say thunderstorms are on the cards on Saturday morning following the heatwave this week which brought the hottest day of the year so farS1

• As many as 17 UK areas could finally see some proper downpours as rain maps turn yellow.S2