A ridge of high pressure over the North Island is expected to move away to the east on Tuesday, while a strengthening north to northwest flow with embedded fronts will be affecting the South Island, MetService said.

“There is low confidence that a heavy rain warning may be required for the ranges of Southern Westland and Fiordland.

“There is also low confidence that severe northerly gales will affect southern Fiordland during the morning and also low confidence of severe northwest gales for Canterbury High Country during the second half of the day.”

On Wednesday, the fronts embedded within a strong west to northwest flow are forecast to move northwards over central and northern New Zealand, with a narrow ridge over the South Island.

“There is low confidence that northwest winds could reach severe gale about exposed parts of Wellington and Wairarapa during the morning and afternoon, and low confidence of severe west to northwest gales about the Tararua District and Hawke’s Bay south of Hastings during the second half of the day.”

A weak ridge of high pressure should move over New Zealand on Thursday.

“Then a band of rain is likely to spread southwards onto the North Island during the second part of the day ahead of a low-pressure system approaching from the north Tasman Sea,” MetService said.

“At this stage, there is minimal risk of severe weather affecting the country.”

The low-pressure system should move southeast over the North Island on Friday, bringing a burst of heavy rain and strong winds.

Meanwhile, a narrow ridge over the South Island is due to weaken with a westerly flow over the lower South Island strengthening later in the day.

“There is low confidence that a heavy rain warning will be required for the upper North Island from Taumarunui, Taupo, Bay of Plenty and far northern Gisborne/Tairawhiti northwards on Friday.

“There is low confidence of severe northwest then severe southwest gales for Northland, and there is also low confidence of severe southwest gales affecting Auckland and northern Coromandel Peninsula later in the day,” MetService said.