'Scary' lightning strike forces Air NZ flight to turn back

Trucks in Arthurs Pass wait for the weather to lift and the roads to clear. Photo / Simon Baker

A lightning strike forced an Air New Zealand plane back to Auckland on Tuesday night because the pilot feared the aircraft had been damaged.

The incident happened part-way through the flight to Wellington as thunderstorms lashed the North Island, and startled even experienced passengers.

"It was scary - everyone knew we had been hit by lightning," passenger Chris Partridge said.

The cabin went "dead silent" after the strike, which was a large flash and a loud crack. "The pilot came on and said they didn't know if there was any damage but we would continue to Wellington."

The first they knew of the plane turning back was when the pilot announced they were descending into Auckland, she said.

Ms Partridge said passengers clapped when the plane landed.

Air New Zealand said the aircraft returned to Auckland as a precaution and was undergoing checks yesterday.

All passengers were transferred to another aircraft and flown to Wellington that night.

Weather experts say the worst of the lightning has passed. WeatherWatch head analyst Philip Duncan said last night that Monday night had been the most active, with 3200 strikes an hour.

"It was unbelievable and it's the most we have ever seen, that's why we put out a weather alert," Mr Duncan said.

Those in the lower part of the North Island, from Taranaki to Wellington, would see some lightning strikes in the next few days although it would not be as bad as those in Auckland in previous days.

Mr Duncan also warned of the possibility that another tornado could hit somewhere from Greymouth to Taranaki.

Meanwhile, MetService weather forecaster Ian Miller said there were heavy snow warnings for the South Island in Fiordland and Westland, south of the glaciers.

Heavy snow is also forecast for Clutha and several road snowfall warnings were also issued last night.

Those roads included Lewis Pass, Porters Pass and Arthurs Pass.

Late last night the MetService was preparing to issue a warning for the Desert Rd.

The weekend is expected to be mostly fine in many parts of the country, including Auckland.