It's not every day your house is struck by lightning and you see a beach ball-sized orb of "orange crackling fire'' levitating in your spare room.

The MetService said the lightning strike was one of 181 to strike within a 60km radius of Alexandra from 2pm to 11pm yesterday.

Cromwell resident Shirley Field said she got the fright of her life when a passing thunderstorm struck her house and two others in Bell Ave, about 7.20pm yesterday.

"I was just putting some mail away in my filing cabinet in the spare room, and there was this almighty bang. I thought, 'What the ...'


"I turned around and there was just this ball. It looked like fire light and it was sparky - it really crackled. As quick as it was there, it was gone.

"I managed not to swear. I've never experienced anything like that before.''

Mrs Field said her carpet was not damaged, but many of her household appliances, such as her flat-screen television and Wi-Fi, had stopped working.

She said her neighbours' houses appeared to have been more badly damaged.

Electrical wiring had melted and plugs were either smoking or had been blown out of walls.

There were some scorch marks up the walls at one of the houses, she said.

Tom and Lanie Hedley were watching television in their Bell Ave, Cromwell, home when they heard a massive boom.

"I thought 'holy hell!' It was awful. It sounded like a bomb going off,'' Mrs Hedley said.

The power went off and they could smell burnt plastic.

A quick inspection of their office at home revealed scorch marks around a power socket where their computer was plugged in, and phone jack points in the bedroom also were hot.

Lightning appeared to have travelled down the phone lines, blowing up the computer router, plugs and power smoother.

Mr Hedley phoned the fire brigade.

Tom Hedley checks the power smoother designed to
Tom Hedley checks the power smoother designed to "calm" power surges to his computer. In the background are the scorchmarks left after the lightning struck. PHOTO: LYNDA VAN KEMPEN / ODT

"I told them there was no fire; I just wanted the fire officers to check around the house just in case.''

An electrician was called and their power was restored later in the evening, but the phone lines and television appeared to be "fried'', thanks to the lightning strike, Mr Hedley said.

The passing storm also caused flooding to several properties in Alexandra.

MetService meteorologist Claire Flynn said the storm was caused by a strong front which brought masses of unstable air to the area between 7pm and 8pm.

The front resulted in lightning strikes and heavy downpours across Central Otago.

The 181 lightening strikes within a 60km radius of Alexandra started about 2pm and moved further east from about 5pm.

Lightning was continuing to strike at 11pm, but was expected to ease overnight.

She said 10.8mm of rain fell at Alexandra Airport between 7pm and 8pm: "10.8mm is definitely quite heavy, but the thing is with thunderstorms, is they can make the rainfall a lot heavier in localised areas.''But, there could have been a lot more rain in other areas, she said.

Between 8pm and 9pm, 12.8mm of rain recorded at Roxburgh and 12.4mm at Millers Flat. Once the front moved through, the rain eased and was expected to clear to scattered showers today.

The number of lightning strikes that came with the front was "unusual, but certainly not unheard of''.

A Fire Service communications spokesman said the storm kept firefighters busy with calls to the Bell Ave lightning strikes in Cromwell and another strike in Lake Hawea, and reports of flooding in Tarbert St, Fox St and Old Bridge Rd, in Alexandra and another flooding callout to the Roxburgh Bowling Club.