Weather: Heavy warnings and watches as school holidays begin

Make the most of the fine weather on Tuesday because heavier rainfall is expected for much of the country from Wednesday.

MetService said the rain would reach many parts of the country on Wednesday and Thursday.

"As we near midweek, MetService is forecasting heavy rain and strong winds to put an end to the sunny spree."

MetService meterologist Mathapelo Makabulane told Midday Report there will be "a little bit of an unsettled period ahead", but it will not be too long before fine weather returned.

"School holidays started off really bright and sunny, but inevitably we do have the next weather system," she said.

"We're expecting that from very late tonight into Wednesday, starting off in the South Island, extending across the South Island, and eventually reaching the North Island. And for the North Island, it looks to continue into Thursday."

She said some regions would be wetter than others.

"Most parts of the country can expect at least some wet weather in the coming days, but the places that look to get the most would be the ranges of Westland, but in reality the whole western South Island," she said.

"Then even in the North Island, places like Northland, parts of the Coromandel and Bay of Plenty, it's been very dry but it could be a different story in the coming days."

But the sunny weather would return next week, she said.

"Once this weather system has moved through we could see some brighter spots some time next week. [There's] a little bit of an unsettled period ahead, but not too long to go before the fine weather returns."

Makgabutlane said there was a possibility of snow for parts of Otago.

"We are still in snow season and we see the return of some snowfall in the Otago region, Southern Lakes into parts of Central Otago," she said.

"If people are going to be traveling on those high level roads, places like the Haast Pass, Lindis Pass, Crown Range Road, we could see some snow settling on those roads."

In the South Island, Heavy Rain Warnings were in place for Westland, Tasman northwest of Motueka, and the Richmond and Bryant Ranges from Wednesday.

In Westland up to 190mm of rain was expected in the ranges with lesser amounts near the coast.

A yellow Heavy Rain Watch was in place for Buller and Grey districts from 10am Wednesday.

While Heavy Rain Watches in the North Island began later in the day Wednesday in Bay of Plenty, Coromandel and Northland.

There have been two Heavy Rain Watches issues in the Bay of Plenty. The first is west of Whakatane and lasts from 6pm on Wednesday to midday on Thursday. The second watch is for the Bay of Plenty east of Whakatane and lasts from 11pm on Wednesday to 3am on Friday.

MetService indicated periods of heavy rain was expected and localised downpours were possible.

There was a high chance the watches will be upgraded to warnings and advised residents to clear drains and gutters in preparation.

An orange Heavy Rain Warning was also issued for Mount Taranaki from 3pm Wednesday with up to 130mm of rain forecast.

A Heavy Snow Watch was also in place for Central Otago and the Queenstown Lakes District.

A Road Snowfall Warning has been issued for Milford Road (SH94) from 11am through until 7pm Wednesday with possibly up to 15cm of snow expected to settle near the tunnel.

Streams and rivers could rise rapidly and there may be flooding and slips, MetService said.

In the North Island on Wednesday the forecast was for scattered showers turning to rain in the north and west, with some heavy falls in the north. While in the South Island, the rain was expected to start in the southeast and spread everywhere.

Temperatures were also expected to be mild.