Humid weather, heavy rain for parts of the North Island

A swathe of rain warnings and watches are in effect for parts of the North Island starting Friday, as humid conditions are expected to spread across the country. MetService has issued warnings ranging from heavy rain to potential thunderstorms, extending into the weekend.

Heavy Rain Warnings Issued for North Island

An orange heavy rain warning is in place for Bay of Plenty east of Ōpōtiki and Gisborne/Tairāwhiti north of Tolaga Bay from 8 p.m. Friday through Saturday. Forecasters expect 80 to 100 mm of rain to accumulate, with the possibility of 130 to 150 mm in localized areas.

“Peak rainfall rates are very dependent on localised convection or thunderstorms, and may reach 25 to 35mm per hour during Saturday morning,” MetService said.

Yellow heavy rain warnings have also been issued for Northland, Auckland (including Great Barrier Island), Coromandel Peninsula, Waikato, Waitomo, Gisborne/Tairāwhiti from Tolaga Bay southwards, Manawatū, Tararua District and Hawke’s Bay throughout Friday.

The conditions are likely to lead to thunderstorm development and localized downpours in some North Island locations. While the risk of downpours is low to moderate, they could have significant impacts if they occur, according to MetService.

South Island to See Heavy Showers and Thunderstorms

A front moving up the South Island on Friday will bring heavy rain to western areas, with some rain extending east of the Alps. Southerly winds moving through on Saturday are expected to bring heavy showers and potential thunderstorms to Otago and Canterbury during the second half of the day.

Meteorologist Alwyn Bakker noted that the exact position of the low center developing east of the North Island remains uncertain, making it difficult to pinpoint the intensity and location of potential severe weather. The forecast position may change daily, and people are urged to check for updates over the weekend.

“We’re currently predicting the rain will stay away until the tail end of Wellington’s Round the Bays on Sunday, which should motivate participants to keep up the pace. However, there will still be strong southerlies during the races, so take advantage of those tailwinds when you can,” Bakker said.

Temperatures to Cool Down After Warm Spell

The top of the South Island experienced a “murky morning” with lingering cloud cover, including at Mt Cook Airport. Temperatures remained high across both islands today, with Invercargill reaching 28C and Alexandra hitting 30C. A heat alert was in effect for Upper Hutt.

However, the run of warmer-than-average temperatures is expected to end this weekend. While a couple of days of warmer temperatures and high humidity remain, cooler air is set to push in from the south.

“A lot of the South Island will have a cooler-than-average weekend, with a few locations seeing a difference of more than ten degrees between Friday’s and Sunday’s maximum temperatures. Cooler temperatures move up the North Island through Saturday and should stick around into early next week,” Bakker advised.