Cool change: Stormy weather on way

An autumn storm is set to bring a dramatic fall in temperatures, severe weather and a dusting of snow likely for the Southern Alps. 

MetService says thunderstorms, heavy rain and gales are expected as two weather fronts slam into New Zealand on Sunday and Monday, enveloping both islands.

An intense front will sweep northeast over the South Island and onto the lower North Island. At the same time, a slow-moving front over the North Island intensifies.

MetService has issued orange rain warnings for overnight until Monday morning for Fiordland north of Doubtful Sound and the Otago headwaters. 

Between 70 to 80mm of rain was expected in the headwaters about the main divide and 50 to 70mm within 15km farther east. 

In Fiordland, 70 to 80mm of rain was forecast, mainly about the ranges. Peak rates of 15 to 25mm/h were expected with possible thunderstorms.

Heavy showers and thunderstorms, with alpine snow, were likely through Monday morning and afternoon.

A heavy rain watch is in place in the ranges of the Westland District. 

Meanwhile, a strong wind warning is in effect for the Canterbury high country, with gusts expected to reach 120km/h in exposed places.

Strong wind watches are in force for Fiordland and Southland from Mataura northward, and Central Otago, including the Queenstown Lakes District overnight. 

Northwest winds may approach severe gale in exposed places.

MetService meteorologist Juliane Bergdolt said the strong winds would bring a dramatic temperature shift, with cooler conditions replacing some of the recent sweltering days.

“Maximum daytime temperatures [will be] in the mid-teens for southern parts of the South Island on Monday and Tuesday. 

“The colder air runs northwards across the country, bringing some snowfall to the tops of the Southern Alps for the early hours of Monday morning.”

Snow may settle above 900m in Fiordland. 

In the North Island, severe gales were expected in Gisborne, Hawke’s Bay, Wellington, Taranaki, Waikato, Manawatū, Marlborough and Nelson. 

Heavy falls were also tipped for Taranaki, Waikato, Manawatū and western parts of the Bay of Plenty.

Most main centres had heavy rain forecast for Monday.

- NZ Herald, ODT Online