• Severe weather warnings include potential thunderstorms, 120km/h gales, and heavy rain across several regions.
• Marlborough and Wellington face strong wind watches, with possible damage to trees and powerlines.
• Heavy rain warnings for Buller and Taranaki Maunga, with up to 200 mm expected in some areas.

Severe weather warnings have broadened across the country with potential thunderstorms, 120km/h gales and heavy rain set to lash several regions across the country.

MetService has forecast heavy rain and strong northwest winds as an active low-pressure system moves east across the South Island early this morning, and an associated front moves across the North Island today.

MetService said it emphasised that from this afternoon, parts of the North Island may experience short periods of heavy rain or downpours — with or without accompanying thunderstorms; this includes Auckland.

Latest severe weather warnings

Warnings and watches for heavy rain and northwest gales are in force for areas of both Islands, so MetService suggests people keep up to date with the latest forecast.

Several regions are facing the threat of severe weather today, with Marlborough and Wellington under an orange strong wind warning.

Both regions could expect damage to trees, powerlines, and unsecured structures.

MetService said driving may be difficult, especially for high-sided vehicles and motorcycles.

Both areas can expect to see severe gale northwest winds gusting up to 120km/h in exposed places.

Marlborough’s warning was expected to end this morning, and Wellington’s at noon.

The regions under an orange heavy rain warning include Buller, the Ranges of Tasman northwest of Motueka, the Tararua Range and the Taranaki Maunga.

Some areas can expect to see 150 to 200mm of rain while they are under the warning.

MetService warns that streams and rivers may rise rapidly, and surface flooding and slips could make driving conditions difficult.

Possible thunderstorms on the way

MetService said that as a front moves northwards through central New Zealand during Sunday morning, there is a low risk of thunderstorms.

“However, the risk is considered moderate before dawn for Westland to Buller and the Alps in Canterbury. Thunderstorms will generate localised heavy rain up to 25mm per hour (possibly more) and strong wind gusts (90-110km/h).”

There is also a low risk of small tornadoes, MetService forecasts said.

Fog in Auckland CBD. Photo / Michael Craig

Colder temperatures expected

A southerly change arriving in the deep south around midday will bring an end to the relatively mild temperatures enjoyed across parts of the country this week.

MetService meteorologist Oscar Shiviti said, “It’ll be colder than what we’ve seen [this week], but nothing out of the ordinary for the time of year.”

Temperatures in Dunedin and Christchurch are expected to fall from forecast highs of 20C yesterday to 12C and 14C respectively today, with Wellington a comparatively mild 18C.

“And there’ll be possible snow down to 800m around Tekapo [in South Canterbury]," this evening.

Parts of Auckland, Hamilton and Bay of Plenty woke to fog yesterday, but there wouldn’t be a repeat today, Shiviti said.

Most North Islanders could expect a rainy albeit mild Sunday, with temperatures around 20C for Auckland, Hamilton, Tauranga, Whangārei and Palmerston North.

Only those in the east would be spared the dreary weather that’s not set to ease until Monday, he said.