A large area of low pressure brings severe weather to Aotearoa New Zealand this week.

MetService is forecasting rain, snow, and strong winds and a raft of Watches and Warnings are in place for a wide extent of the country. 

Forecasters are keeping a close eye on the southeastern South Island where heavy rain is expected on Monday and Tuesday. North Otago, Dunedin, and Clutha are currently under an Orange Warning for Heavy Rain.

“It’s not often we see persistent rain like this in this part of the country, and the area does not need large amounts of rain for impacts to be felt,” says MetService meteorologist Mmathapelo Makgabutlane.

“We could see surface flooding, especially in eastern areas of Dunedin, so people are advised to keep up to date with the latest information from MetService, as well as their local authorities.” 

Other parts of the country in line for possible heavy rain include western Tasman, also under an Orange Warning for Heavy Rain, as well as Southland, the Westland District, western Marlborough ranges, Mount Taranaki, and eastern Bay of Plenty, all under Heavy Rain Watches.

Extensive snowfall is expected for Monday and Tuesday in the lower and central South Island.

Inland Southland, Otago and Canterbury have a possibility of heavy snow above 500 to 800 metres, with lesser snowfall amounts possible down to 200 to 300 metres.

South Canterbury High Country could see 30 to 40 centimetres of snow settling above 500 metres.

“This is expected to be a wide-reaching snow event, especially for farmers and road users,” Mmathapelo says.

Other parts of the South Island may also see snow, including Banks Peninsula and inland Marlborough, although at this stage unlikely to be heavy.

Road Snowfall Warnings have been issued for high level roads and mountain passes that could be affected by snow.

“Remember to drive to the conditions, and check Waka Kotahi NZTA’s website for how roads may be affected,” Mmathapelo advises.

Strong winds will be something to watch, especially for the western South Island where wind gusts could reach 120 km/h in valleys and isolated exposed areas.

An Orange Warning has been issued with the possibility of fast-moving winds.

While rain is on the cards for much of the country this week, the wettest weather is expected in the east of both the North and the South Islands.

During Tuesday, the rain extends to the Canterbury Plains, and this shifts to Wairarapa and Hawke’s Bay from Wednesday and Tairāwhiti Gisborne on Thursday.

For the North Island, places that have had recent heavy rain could see some large rain accumulations later this week.

“This is a developing situation, and although it’s all happening in the South Island during the early part of the week, it’ll be a good idea for people in the eastern North Island to also have a close eye on the forecast,” Mmathapelo comments.

By the end of the working week, settled weather makes a return as a ridge of high pressure moves onto the country, bringing a close to an active week of weather.