MetService National Weather: November 16-18.
More than 2,500 lightning strikes have struck both inland and offshore as MetService issued severe thunderstorm warnings for much of the North Island.
MetService meteorologist Angus Hines said 2,597 lightning strikes have been recorded since noon, mostly in the lower parts of the North Island, such as Wairarapa and inland Manawatu.
There were also isolated strikes in other parts of the country such as Waikato, Marlborough, inland Canterbury and inland Southland.
Waikato, Waitomo, Taumarunui, Taupo, Hawkes Bay, Taihape, Wanganui, Manawatu, Tararua, Wairarapa have severe thunderstorm watches from 1pm to 7pm today.
MetService warns that these storms will become “heavy” in the early evening, producing localized downpours with intensities of 25 to 40mm per hour.
“Rainfall of this intensity can cause surface and flash flooding, especially in low-lying areas such as streams, rivers or narrow valleys, and also lead to slips,” MetService advised.
“Driving conditions will also be dangerous with surface flooding and poor visibility in heavy rain.”
The storm is being caused by a low-pressure system slowly moving across the Tasman Sea, pulling warm air and moisture across land ripe for showers, MetService meteorologist Tui McInnes said.
“To make matters worse, it’s late in the year, which means the sun is high in the sky, sea breezes are strong, and that adds to the ingredients for thunderstorms,” McInnes said.
“So don’t be surprised if you see a few flashes in the sky and hear a roar from above.”
Showers and thunderstorm waves will hit much of New Zealand, particularly the North Island.
Downpours are also likely.
Risk of localized flash floods and slips.
Maybe tomorrow afternoon clearing ⛅️ for the upper north island. pic.twitter.com/x3hoQEMse0
— NIWA Weather (@NiwaWeather) November 16, 2022
Sticking with the mix of extremes we’ve had over the past week, with scorching temperatures in the south and thunderstorms in the north, Mcinnes said: “If you’re not going to get wet, expect some sun”.
“Given the weather scenario at hand, expect the wet weather to be localized – meaning while one town could get soaked in the afternoon, the next town down the road could remain completely dry,” Mcinnes said.
Later in the evening, Hines said the torrential downpour and thunder are likely to hit tomorrow, with Northland getting the worst of it.
“The most intense rain will start in Northland tomorrow but move south as the day progresses,” Hines said.
“So it looks like it’s going to basically be all over the North Island by the end of the day and then move on to the north and east of the South Island over the weekend.”