The Met Office has issued a rare amber thunderstorm warning for the Southeast of England from 8pm Friday until 5am Saturday. Parts of eastern and southeastern England are due to be hardest hit, with rain downpours reaching 30-50mm in a short space of time, increasing the risk of surface water flooding. There is also to be large hail, strong and gusty winds in excess of 40-50mph, and lightning. The weather office warned: “Some communities are likely to become cut off if roads flood.

“Where flooding or lightning strikes occur, delays and some cancellations to train and bus services are likely. Spray and sudden flooding are probably leading to difficult driving conditions and some road closures. Flooding of homes and businesses is likely and could happen quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds. Fast flowing or deep floodwater is likely, causing danger to life.”

The Met Office also warned of power cuts, which are “likely to occur”. It advised checking on vulnerable people as they may need support with food and medical supplies.

The weather agency also suggested preparing a flood kit before the storms are due to hit, as this could “save you from loss or damage due to flooding to your home or business“.

A flood kit should include insurance and any other important documents, a torch and spare batteries, a first aid kit, prescription medicines, and supplies for caring for family members or pets, such as warm, waterproof clothes, blankets, food, and water.

This latest warning follows a yellow alert for thunderstorms from 7pm Friday to 6am Saturday and another one from 4pm to 11:59 pm today.