"Wind gusts of this strength can cause some structural damage, including trees and power lines, and may make driving hazardous.
"If any tornadoes occur, they will only affect very localised areas."
This morning one such tornado ripped quickly through a residential area in Waikanae Beach, tearing the roof off at least one house and damaging others.
No injuries have been reported from the brief incident.
Strong winds are forecasted across most of central New Zealand today.
Orange heavy rain warnings are in place for the Tasman ranges west of Motueka, Buller and Westland.
170mm to 250mm of rain is expected to accumulate around the ranges south of Otira, MetService says.
Heavy rain watches are in place for the Richmond and Bryant Ranges, the Rai Valley area and northern Marlborough Sounds as well as Mt Taranaki and the Tararua Range in the North Island.
Strong wind watches are in place for the Canterbury High Country, Wellington, Taihape, the ranges of Hawke's Bay, parts of Wairarapa, inland Marlborough and the Marlborough Sounds.
It follows a night of thunderstorms across the country on Tuesday.
There were 640 lightning strikes over the land in the 12 hours to 8.30am.
"Though the risk of thunderstorms has decreased over the upper North Island they will continue over western regions south of Waitomo during today. As each line of showers passes over these regions it will bring another possible flash of lightning, period of flooding and damaging gusts," MetService warned.
"It's a turbulent start to winter but not a cold one. As the low bringing this active weather moves east of the country on Friday, not only will it signal the start of a slow easing trend in the weather but it will bring in cooler air in from the south."
