The last few days of unbroken sunshine and dry conditions in Essex are set to come to an inglorious end, according to Met Office forecasters.
Low pressure developing towards the west of the UK is expected to stretch eastwards, bringing with "moist and unstable" conditions, and potential heavy and thundery showers.
However, temperatures are not expected to dip too much further, remaining at a steady 19C.
The unsettled conditions are also expected to linger into Saturday, with showers expected in the morning.
The Met Office's chief forecaster said: "Daytime heating will assist the development of heavy showers and thunderstorms.
"These are likely to become slow-moving and organised into bands giving some places 15-20 mm of rain in an hour or less and perhaps 40 mm in 2 or 3 hours.
"Hail and lightning will be additional hazards. As with the nature of showers, some places will escape the heavier ones."
