Weather: Active thunderstorms sweep North Island causing localised power outages; heavy rain and large hail reported

An active, unstable band of thunderstorms is sweeping through much of the North Island, causing localised power outages and hazardous driving conditions.

MetService meteorologist Ngaire Wotherspoon told the Herald there was a very active, broad line of thunderstorms moving northeast over the North Island on Sunday afternoon.

At 1.23pm, MetService issued a severe thunderstorm watch over Waitomo, Taumarunui, Taranaki, Taihape and Whanganui, warning heavy rain, hail, squally wind gusts and frequent lightning would follow.

As of 3.30pm, Wotherspoon said it was positioned just east of New Plymouth, with scattered thunderstorms further north near Taupō, Rotorua and inland Bay of Plenty,

“It is a very unstable situation right now and in that line itself over Taranaki and inland Whanganui, there are some very frequent lighting strikes happening,” Wotherspoon said.

⚡ A Severe Thunderstorm Watch is active for Waitomo, Taumarunui, Taranaki, Taihape and Wanganui until 5pm
⛈ Expect heavy rain, hail, squally winds and frequent lightning
Localised damage could affect power connections
🏘 Should severe weather approach, take shelter immediately pic.twitter.com/gFzPYZiR1R

— MetService (@MetService) September 22, 2024

Wotherspoon said from 12pm to 3pm, there had been about 6800 lightning strikes inland over the North Island.

“Most of them [have been] concentrated in that area over Taranaki and Whanganui. They won’t all be to the ground, most of them are cloud to cloud, but this will be making noises.”

The lightning is widespread and frequent and MetService believed it had been causing some localised damage to power connections.

“That could continue in some areas within that watch,” Wotherspoon said.

She said MetService were “keeping a close eye” on the thunderstorms and had a dedicated thunderstorm forecaster working today.

⛈ Heavy rain, thunderstorms and possible hail are spreading over Whanganui and Taranakihttps://t.co/prKU7NLNY1 pic.twitter.com/2VUtFbpYMX

— MetService (@MetService) September 22, 2024

“Our chart for today covers up to Waikato and also out into Hawke’s Bay, so it is a good chunk of the North Island that’s under risk.

“Auckland is on the higher end of the low risk last I checked, so we are definitely keeping a close eye on it. Our weather models weren’t indicating that it was up into that moderate risk area but I think it is a very active situation so it’s definitely keeping us on our toes,” Wotherspoon said.

The severe thunderstorm watch was forecast to lapse at 5pm, but Wotherspoon said thunderstorms could continue into the evening in more northern areas as the band moves northeast.

MetService advised that should severe weather approach, or if you’re feeling threatened, take shelter immediately.

A Herald reporter in Taranaki said the thunderstorms began moving in from around midday and progressively worsened.

“[It was] very loud, lots of lightning and quite widespread over a good chunk of eastern Taranaki.”

As he drove through the thunderstorms, large hail stones began slamming into the windscreen of his car.

“I’ve driven through some storms before but that one was pretty interesting. There were decent hail stones, quite heavy rain and lots of lighting all around us.”

The thunderstorms swept over eastern Taranaki in the space of a few hours.

He said power to his parents’ farm in Taranaki had been knocked out in the storm but had since been restored.