Weather: Severe summer thunderstorms hit South Island, torrential rain and lightning expected

The wild summer storms have made their way down the country as the lower half of the South Island braces for torrential rain and lightning.

MetService has issued severe thunderstorm warnings and watches for much of the east and lower South Island and the public is advised to take cover from the storm.

It's been an unruly past few days for parts of the North Island with heavy rain and strong winds forcing holidaymakers to abandon popular summer hotspots like the Coromandel Peninsula.

The weather forced the cancellation of concerts, and large slips and flooding have closed many eastern roads.

Now the bout of wild weather has hit the South Island with scattered thunderstorms starting to develop across the east and south of the island.

Severe thunderstorm warnings have been issued for Ashburton, Timaru, Waitaki, Waimate, Clutha, Dunedin City, Gore and Southland.

These thunderstorms are expected to be accompanied by torrential rain, large hail and frequent lightning. Torrential rain can also cause surface and flash flooding about streams, gullies and urban areas, and make driving conditions extremely hazardous.

The National Emergency Management Agency is advising people in the area to take shelter, preferably indoors away from windows, move cars under cover or away from trees and check that drains and gutters are clear. The public is also advised to avoid streams and drains and beware of fallen trees and power lines.

Weather watches and warnings.
Weather watches and warnings. Photo credit: MetService

A severe thunderstorm watch has been issued from noon Friday until 10pm for the Canterbury plains, Canterbury high country, north Otago, Central Otago and Dunedin.

"There is a risk that thunderstorms could become severe and produce localised downpours with rainfall rates of 25 to 40mm per hour," MetService said.

NIWA said there is a chance most areas in the South Island will experience a small amount of lightning.

Safeswim has issued safety warnings at many popular Christchurch and Dunedin beaches due to strong currents, strong wind, large surf and surging waves. Warrington Beach north of Dunedin also has a risk of lightning strikes and beachgoers are urged to leave and seek shelter.