Photo: Screenshot / MetService
MetService have forecast heavy rain and strong northwest winds as an active low pressure system moves east across the South Island late Saturday and early Sunday, and an associated front moves across the North Island on Sunday.
An orange-level heavy rain warning is in place for the Tararua Range, the ranges of Tasman northwest of Motueka, the headwaters of the Canterbury Lakes and rivers about and south of Arthur's Pass, Buller, and the ranges of the Westland District from Saturday afternoon.
Between 60 and 150 millimetres of rain is expected to accumulate, but there is only a minimal chance of the orange-level warning upgrading to a red-level one.
MetService has warned surface flooding, slips, and difficult driving conditions are possible.
Thunderstorms are also possible for Canterbury and the West Coast.
❗Thunderstorm Risk Outlook for Tomorrow
— MetService (@MetService) May 17, 2025
Our team of Meteorologists have carefully analyzed the upcoming weather patterns and put together a thunderstorm risk forecast for tomorrow.
⛈We’d like to emphasize that from tomorrow afternoon, parts of the North Island may… pic.twitter.com/CLnhwTCEl2
Meanwhile, an orange-level strong wind warning is in place for Marlborough, Wellington, and the Canterbury High Country from Saturday afternoon. While MetService have warned of severe gale northwest winds gusting 120km/h in exposed places, there is still only a minimal chance of upgrading to a red-level warning.
However, damage to trees, powerlines, and unsecured structures are possible. Driving may also be difficult, especially for high-sided vehicles and motorcycles.
There is also a heavy rain watch for Bay of Plenty east of Ōpōtiki, Taumarunui, Waitomo, Waikato south of Raglan, Tongariro National Park, Taupō west of the Lake, Taranaki Maunga, Richmond and Bryant ranges, also the Rai Valley, ranges of the Grey District, headwaters of the Otago Lakes and Rivers, and Fiordland north of Doubtful Sound - all with a moderate chance of upgrading to a warning.
A strong wind watch has been issued for the Wairarapa, also with a moderate chance of upgrading to a warning.
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