A witness has described how his neighbours escaped unharmed after a lightning strike caused the roof to collapse and flames to spread through two semi-detached houses.

A 70-year-old woman was assessed by paramedics after the strike severely damaged the two houses in Mercia Avenue, Andover, Hampshire, on Saturday morning.

The incident came as storms hit the south of England, bringing the recent heatwave to an end.

Neighbour Barrie Austen, 79, told the PA news agency: “There was this enormous bang, it was obviously the lightning, I think it woke the rest of the street up.

“I saw the flickering and when I looked out I saw the roof of the semi-detached house completely ablaze and it had completely gone.

“The side that supports the roof, that collapsed as well and then the flames spread into next door.”

He said that two sisters live at the property and one was checked over by ambulance crews.

He added: “She seemed shaken but seemed OK, no real physical problems. I think the lightning hit the roof, woke them up and they just got out.”

The woman was assessed by paramedics but did not require hospital treatment, according to Hampshire Fire and Rescue Service.

A spokesman said: “Crews from Whitchurch, Amesbury, Ludgershall, Winchester, Overton, Basingstoke and Rushmoor were called to Andover early this morning following a house struck by lightning.

“Two semi-detached houses were severely damaged in the incident.

“A 70-year-old female was assessed by ambulance crews on the scene but was not taken to the hospital.

“One aerial ladder platform and two 45mm jets were used at the incident.”

The spokesman added that fire crews were damping down the property.

The lightning strike came after the Met Office warned of thundery conditions for southern and central areas, with yellow weather warnings in force during the weekend.

A thunderstorm warning is in place until 10pm on Saturday, with the possibility of heavy rain that could cause disruption and flooding.

The warning covers southern England and Wales, potentially disappointing anyone who hoped for a dry, sunny trip to the coast.

Music lovers at the Latitude festival in Suffolk will be hoping they can avoid a muddy mosh pit while anyone with camping in mind may want to pack wisely.

Saturday is likely to see frequent lightning, thundery rain and strong, gusty winds in the areas covered by the thunderstorm warning.

There is also a risk of large hail falling in a few places, and where there are heavy downpours there could be up to 35mm of rain falling within an hour, bringing the risk of flooding.

A second yellow warning has been updated by the Met Office advising of the possibility of thunderstorms across southern parts of England and Wales on
Sunday from 5am to midnight.

Forecasters said some of the heaviest showers are expected in the South East in the morning, before falling more widely across the warning area as the day goes on.

There is the potential for up to 80-100mm of rainfall to build up in some places over the course of the day, which will bring a risk of flooding and some poor driving conditions with surface water likely on roads.

Met Office principal operational meteorologist Frank Saunders said: “This more unsettled weather brings a risk of torrential downpours and flooding in some places.”

Forecasters said the unsettled weather looks set to continue early next week, with more persistent rain expected for much of the UK.

A Met Office amber warning for extreme heat had been in place for England until midnight on Thursday.

The country reached its hottest temperature of the year on Tuesday when 32.2C was recorded at Heathrow Airport in west London.