Weather: Thunderstorms, heavy wind gusts expected to hit North and South Islands

Kiwis can expect to hear more thunder and lightning as several fronts and troughs move over the country bringing heavy showers with them.

MetService meteorologist Jessie Owen said the current weather was caused by a low-pressure system in the Tasman Sea.

“This low is dragging warm, muggy air from the north down over the country, which combined with the extra heating we are getting from the sun now that we are heading into summer makes conditions ripe for showers and thunderstorms.”

Today, it is expected there will be periods of rain and showers across the whole North Island, with a band of more persistent rain moving down from the north, due to a front extending out from the low-pressure system, Owen said.

“There is a moderate risk of thunderstorms across the whole North Island, any areas which do see thunderstorms will experience heavy rain, there is also a low risk of downpours associated with severe thunderstorms for the North Island.”

🌩🌩🌩

Hear any rumbles yesterday? Plenty of activity over Aotearoa/New Zealand yesterday!

More lightning and thunder possible today - check out the details https://t.co/BZWb7ZPiRd pic.twitter.com/STIOtEeUNg

— MetService (@MetService) November 17, 2022

Owen said showers were also expected for most areas of the South Island with the band of rain reaching more northern areas (Nelson/Tasman, Buller, Marlborough, and northern parts of Westland and Canterbury) by late afternoon or evening.

These northern areas of the South Island are also within the moderate risk of thunderstorms and low risk of severe thunderstorms, so heavy showers are also likely there.

“For the rest of the South Island, the risk of heavy showers is lower apart from an area in Central Otago and Fiordland.”

In the weekend, they were not expecting it to stop for a break, Owen said.

“A warm muggy northerly flow is going to keep producing showers across most of Aotearoa through Saturday and Sunday, with the most shower activity expected in the afternoons and early evenings when the heating from the sun is at a maximum.”

This morning there was a “moderate risk of thunderstorms” about Northland, a MetService spokesperson said.

“These thunderstorms may be accompanied by localised heavy rain with intensities of 10 to 25mm per hour and strong wind gusts of 90 km/h, especially near the coast.

“There is a low risk that these thunderstorms could become severe, producing localised downpours with 25 to 40mm per hour or small tornadoes, especially about the eastern coast. In the afternoon, the risk of thunderstorms reduces to low.”

For Auckland, the Coromandel Peninsula, Waikato and Waitomo the risk remained till the afternoon

There may be localised heavy rain with intensities of 10 to 25mm per hour associated with thunderstorms.

“Also, mainly over and near the Hauraki Gulf, strong wind gusts of 90km/h are possible,” MetService said.

From Taranaki, Taumarunui and Bay of Plenty southwards and the northern South Island, there was a moderate risk of thunderstorms this afternoon and evening, the spokesperson said.

MetService said these thunderstorms may bring localised heavy rain with intensities of 10 to 25mm per hour and a low risk of severe thunderstorms and downpours with intensities of 25 to 40mm per hour.

For much of the inland areas of the South Island, there was a low risk of thunderstorms this afternoon and evening, but for parts of Fiordland, the Queenstown Lakes District, Central Otago and Southland, there was a moderate risk of thunderstorms this afternoon, the spokesperson said.

No other areas of severe convection or thunderstorms were expected.

Heavy rain watches have been put in place for Northland, Auckland, Tasman west of Motueka, Wellington and the Tararua Range, Kaikōura Coast and Ranges, Canterbury and North Otago and Dunedin.