Orange warnings cover Bay of Plenty and Taranaki as storms sweep the North Island

Thousands of New Zealanders started the weekend in the dark and the wet as a violent band of storms rolled up the country, knocking out power overnight and leaving the top half of the North Island braced for heavy rain, thunder and the small chance of a tornado.

The system first lit up the South Island. MetService recorded thousands of lightning strikes overnight, the bulk of them in the south, and the flashes were dramatic enough to be filmed streaking across the sky over Nelson. MetService meteorologist John Law told RNZ there had been roughly 5000 strikes through the night, most of them over the South Island, with Friday shaping up as the most active day of the run.

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The lightning came with a price. Homes from Stoke through to Tākaka lost electricity just before 9pm on Thursday when the front swept through the centre of the country. Lines company Network Tasman worked through the evening to bring supply back, and by 1am there were no unplanned outages left on its network. Even so, it was an uncomfortable night for households in the upper South Island who went to bed without power as the rain hammered down.

By Friday the worst of the weather had shifted north. MetService placed orange heavy rain warnings, its second-highest alert level, over two regions. The eastern Bay of Plenty, east of Whakatāne, sat under a warning running from 5pm Friday to 5am Saturday, with 70 to 90 millimetres of rain forecast and peak bursts of 20 to 30 millimetres an hour over the ranges. Taranaki north of Eltham was placed under its own orange warning, with 90 to 120 millimetres expected on the lowlands and as much as 150 to 200 millimetres about Taranaki Maunga, the mountain that dominates the region.

Forecasters warned that streams and rivers could rise quickly under that kind of rainfall, raising the risk of surface flooding, slips and hazardous driving. Civil Defence echoed the message, urging people in the warning zones to watch for slips, flooding and possible road closures and to delay travel if conditions turned bad.

A long list of other districts sat under the lower-level heavy rain watch, including the western Bay of Plenty, Rotorua, Taupō, Waitomo, Taumarunui, Tongariro National Park, Horowhenua, the Kāpiti Coast, Wellington and the Tararua Range. On top of that, MetService issued a severe thunderstorm watch for the top half of the North Island for Friday evening, flagging downpours of 10 to 25 millimetres an hour, wind gusts of up to 100 kilometres an hour and a low risk of a small tornado forming in the most unstable cells, according to the New Zealand Herald.

Road authorities took no chances on the most exposed routes. State Highway 35, the coastal road that loops around the East Cape, was set to close from 10pm Friday until 8am Saturday as the heaviest rain moved through, cutting off the quickest link for several small communities until the danger passed.

Wellington, meanwhile, was dealing with a grubbier problem. Heavy rain overwhelmed parts of the capital’s wastewater network and pushed raw sewage onto the streets near Lyall Bay and Island Bay, with residents reporting faecal matter and sanitary products coming up through maintenance holes. After a separate discharge of raw sewage at Tarakena Bay, Health New Zealand advised people to stay out of the water from Ōwhiro Bay around to Breaker Bay for 48 hours, ruling out swimming, surfing and kayaking along a popular stretch of the south coast.

The storms are the latest reminder that an unusually warm start to winter has not meant a quiet one. Just days earlier Wellington broke a 55-year-old June heat record, and forecasters say the country is now almost certain to be in El Niño conditions through June, July and August. Earth Sciences New Zealand puts the chance of El Niño at about 95 percent for the three months, a pattern that tends to drive more wind from the west and south and leaves much of the North Island and the east of the South Island leaning towards drier than normal overall, even as individual fronts like this one deliver a soaking.

For now the advice is simple enough. People in the warning areas have been asked to keep up with the latest forecasts, secure anything loose around the property, avoid driving through floodwater and check on neighbours who might struggle if the power goes out again. The heaviest falls were due to ease overnight into Saturday, and MetService expected the warnings to lift through the early hours as the front cleared to the east.

Did the storm reach your part of the country, and did your power stay on? Tell us what you saw in the comments below.

This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂