Warm, moist weather as low-pressure system over NZ

A heavy rain warning has been issued by MetService. Photo / Michael Cunningham

Warm and moist weather is the name of the game this week with a swath of tropical air over Aotearoa New Zealand.

Rain, associated with a low-pressure system from the north, continues to fall on the North Island on Monday.

The areas from the Coromandel Peninsula to the Kaimai Range and in Gisborne/Tairāwhiti north of Tolaga Bay are under orange heavy rain warnings until 8pm and 9pm respectively.

“We’ve already seen 200mm of rainfall recorded at the Pinnacles on the Coromandel Peninsula over the last 24 hours, which, even given the exposure of this mountainous station, is very impressive,” said MetService meteorologist Katie Hillyer.

“MetService expects a further 70-90mm of rain to fall in those areas today.”

High humidity will be felt across the North Island too.

“Warm, humid air with plenty of cloud cover acts like an insulative blanket, meaning warmer nights and uncomfortable sleeps this week.”

The poster child of this effect was Rotorua, which saw a difference of only 2C between its maximum temperature yesterday and its minimum this morning.

Honourable mentions went to Whanganui and Hawke’s Bay, where temperatures were set to crack 30C over the next couple of days – a distinct change from the cool summer experienced in the east thus far.

Overnight, the main action switches from northeastern areas of the North Island to the South Island, with rain associated with an approaching low-pressure system from the Tasman Sea.

The ranges of the Tasman District have been upgraded to an orange warning, with 80-100mm expected to fall between 9pm tonight and 7am on Tuesday.

A heavy rain watch is also in place for the Richmond and Bryant Ranges. Rain will spread into eastern parts of the South Island tomorrow morning, soaking some of those dry soils.

“Thunderstorms could also be on the cards Tuesday afternoon and evening for Canterbury down to Southland, as well as Westland through to Buller,” warned Hillyer.

Periods of rain will continue across much of the country through to Thursday, with today and Tuesday being the most active days.

“Cloudy and wet will be the real descriptors for much of the country until Thursday and into Friday, when a ridge of high pressure starts trying to push out that humidity and bring in some fresher air.”