The Met Office have issued a yellow warning for heavy rain for Northamptonshire, Lincolnshire, Cambridgeshire, Essex, Norfolk, Peterborough, Southend-on-Sea, Suffolk, Thurrock, Hertfordshire, Milton Keynes and Bedfordshire.
The warning is valid from 4pm until 10pm on Saturday 12 July 2014
The Met Office warning says: "Heavy showers and isolated thunderstorms are likely to develop over some eastern parts of England later this afternoon and through the evening.
"The public should be aware that localised downpours could lead to temporary surface water flooding."
The Met Office Chief Forecaster's assessment is: "Temperatures into the mid-20sC seem likely to trigger scattered heavy showers and thunderstorms from mid-afternoon and through the evening.
"There is the risk of 20-30 mm of rain falling within an hour in a few places, although as is often the case with showers, many places will miss the heaviest rain and some areas will escape with a dry day."