There have been more than 1000 lightning strikes recorded in two hours, sparking two fires on the West Coast.
MetService said between 5.30am and 7.30am on Saturday, it observed 1300 lightning strikes over the country.
Most were recorded on the South Island’s West Coast and over the Tasman Sea, a spokesperson said.
Firefighters put out two separate fires in Greymouth that began due to the lightning strikes.
Crews were called to a report of smoke coming from a property shortly before 6am.
The two crews were then called to a commercial building in the town centre, where another lightning strike had ignited a fire.
There were no injuries and both fires have since been put out.
MetService meteorologist Dan Corrigan said the stormy front has since moved beyond the Grey District.
“We’ve had an active band of storms work its way northwards up the West Coast, it’s just coming around upper Buller so around Kahurangi National Park is where it is at the moment.”
He said Tasman, coastal Canterbury and Otago and Kāpiti Coast to Raglan may also see thunderstorms on Saturday.
Meanwhile, a strong wind watch is in place for Taranaki.
The watch is in place from 10am until 8pm.
“Westerly winds may approach severe gale in exposed places,” MetService said.
Taumarunui, Taupō, Taihape, Whanganui, inland Hastings District, Central Hawke’s Bay District, and Manawatū north of Hunterville are also under a strong wind watch from 11am until 11pm.