Houghton Bay in Wellington during a strong swell in 2021. Photo: RNZ / Dom Thomas
Swells around Wellington are forecast to increase overnight, though not quite to the same height the South Island experienced in a windy start to the week.
On the West Coast, swells reached 7m high, MetService told RNZ, and up to 6m on the east.
"Overnight tonight, a swell arriving from the southwest will sweep up the eastern coast and up towards Wellington and Cook Strait," meteorologist John Law told RNZ on Tuesday afternoon.
"Currently the swells around the capital are around 1m, but these are forecast to increase overnight and into tomorrow with long-period swells reaching 3-4m during Wednesday morning."
Southerly winds in the Cook Strait will reach 15 knots (27km/h) in the morning, easing to 10 knots (18km/h) in the afternoon.
On Tuesday afternoon, gale warnings were in place for Chalmers, Conway and Rangitata, off the coast of the South Island, and the Chatham Islands.
Heavy swell warnings were in place for Wellington, Kapiti-Porirua Coast and Wairarapa.
Swells are caused by strong winds far away. Local winds would only have a "slight" effect on wave heights around Wellington and Kapiti on Wednesday, MetService's site said, adding up to 1m to wave heights. No recreational warnings were in place for the region.
On Thursday, a new front was expected to cross the South Island from the northwest, moving northeast up the island and bringing with it a small chance of rain in Fiordland, and gale-strength winds in Fiordland, Southland, inland parts of Otago and about the Canterbury High Country.
By Saturday, the weather was expected to fine all over, thanks to a high pressure ridge, though strong winds could return to the south of the South Island on Sunday.
"Once we head beyond Wednesday, we see an easing trend in the swells as things begin to settle down and high pressure re-establishes itself over the country," Law said.