A WARNING of possible localised flooding and lightning strikes in Swindon and Wiltshire has been issued by the Met Office.

The yellow 'alert' warning, valid until 8pm today, says: "Scattered heavy, perhaps thundery, showers are expected to develop on Wednesday afternoon.

"Please be aware of the risk of localised flooding and lightning strikes.

"The showers will die out steadily through Wednesday evening."

Wiltshire luckily missed yesterday's downpours, which caused flooding in some areas.

The Met Office chief forecaster said: "Whilst today's airmass is less unstable than the one which brought Tuesday's torrential downpours, there is still the likelihood of some heavy, thundery showers developing as temperatures rise this afternoon.

"Many places will miss these, but where showers do occur they are likely to be heavy and slow-moving, leading to surface water on roads and difficult driving conditions. Lightning may also be a hazard."

Thunderstorms and lightning flooded roads yesterday, causing a temporary loss of power at Luton Airport, and set alight trees, hoardings and telegraph poles.

In south London, 1.3 inches (35mm) of rain fell in the space of an hour causing three cars to become submerged in 6.5 feet (2m) of water.

Darlington Imoh was one of three drivers rescued from a flash flood at Wallington, Sutton, and said he feared he would drown before escaping through the window of his vehicle with the help of firefighters.

Mr Imoh, 60, said he "hugged and thanked" firefighters after they saved him.

He said: "I couldn't open the door because of the force of the water. I unwound the window and struggled out and then I was rescued by the fire brigade - that's why I am alive standing here now.

"It is the closest I got to death. Survival was my biggest concern, to survive."

Mr Imoh's Vauxhall Zafira, a Mercedes and an Alfa Romeo got caught in the water on Manor Road, outside Wallington train station and underneath a railway bridge where the road dips.

London Fire Brigade said it had received more than 100 flood-related calls.

The Home Office said border security was not compromised because of the loss of power at Luton Airport.

A spokesman said: "Luton Airport experienced a temporary loss of power as a result of thunderstorms in the area.

"However, to be absolutely clear, border security has not been compromised in any way and we are able to carry out exactly the same security checks as we would normally."

An airport spokesman said queues were longer than expected but terminal staff were helping passengers, fast-tracking anyone in special need and handing out drinking water.

"It's not ideal but we have coped with it relatively well," he said, adding that the main computer system was back up within about two hours.

Grahame Madge, of the Met Office, said the downpours could continue to cause localised flooding, surface water flooding and travel disruption today.

"What we have is a situation where we have warm, very moist air coming in from the continent and the heat added to the warm air causes it to rise and sees the development of these showers," he said.

"The intensity of those can be very severe in localised areas - as we have seen in some places like London and Brighton there has been very heavy rainfall.

"And that has led to flooding in some areas - which is exactly why we issued the warnings."

The Environment Agency said 1.3ins fell in an hour in south London, which Mr Madge said was an "exceptional" amount.

"We would have expected in an average June 49mm (1.9ins) of rain to have fallen in London on average across the month - it is significant," he said.