Lightning strikes in Adelaide overnight.
Lightning strikes in Adelaide overnight.

A teenager has been taken to hospital after being struck by lightning as thunderstorms sweep across South Australia.

The SA Ambulance Service said the incident occurred at a Hallet Cove property in Adelaide's southern suburbs on Monday.

A spokeswoman said the 15-year-old boy was conscious and in a stable condition when he was taken to the Flinders Medical Centre.

Earlier emergency authorities warned people to take precautions with thunderstorms, heavy rain and strong winds forecast to hit the state.

Ten of thousands of homes have lost power at some stage today as strong winds from thunderstorms damaged powerlines and lightning sparked fires across the state.

More than 100,000 lightning strikes in the past 24 hours also started several fires, including three that burned out of control on the Eyre Peninsula.

While they are now under control, a blaze at Darke Peake caused $140,000 damage.

Fierce storms also blacked out about 20,000 homes and businesses, and SA Power Networks says it could be hours before electricity is restored to them all.

The worst affected areas were Kangaroo Island, the Adelaide Hills and suburbs in Adelaide’s inner north around Broadview, Clearview and Greenacres.

The State Emergency Service (SES) has also been run off its feet, responding for more than 80 calls for help, mainly for fallen trees.

The Bureau of Meteorology re-issued a severe thunderstorm warning at 4pm for the Adelaide Metropolitan area, Mount Lofty Ranges, Eastern Eyre Peninsula, Yorke Peninsula, Kangaroo Island, Flinders, Mid North and parts of the Murraylands, Upper South East, North West Pastoral and North East Pastoral districts.

“Scattered thunderstorms are occurring with a strong frontal system which is expected to move across central and eastern parts of SA during this afternoon and evening,” the warning reads.

“Some of these thunderstorms are likely to be severe with damaging wind gusts and very heavy rainfall that may lead to flash flooding.

“There is also a risk of large hailstones north of about Whyalla.”

Gusts between 80km/h and 90km/h have been recorded on the Yorke Peninsula, in the Mid North and Mount Lofty Ranges already today, with northerly winds average 60-65km/h.

Strong winds blew a tree down onto this car at Nailsworth this afternoon. Photo: Alex Fragnito, 7News

Latest From 7News