Heavy rain and strong northwesterlies are expected to hit most parts of the North Island today as a northwest flow and several embedded troughs move over the Island.
The rain was expected to be persistent in areas including Auckland, Northland, Coromandel and Bay of Plenty until early afternoon when it will ease to showers.
"It's a fairly active weather situation," said MetService meteorologist Ravi Kandula.
In the South Island, heavy snow warnings are in place for southern Westland and Fiordland, where snowfall has closed three state highways.
A severe weather watch was also in place for western areas of the South Island for periods of heavy rain and snow. People in Canterbury, Otago and Southland are also being warned about strong to gale force west to northwesterly winds, which may become severe in exposed places.
MetService has issued a warning that heavy snow could also damage trees, power lines and cold conditions may cause stress for livestock.
State Highway 1 Goose Bay to Peketa, Lewis Pass and SH94 Hollyford Valley Rd intersection to Chasm Stream Bridge are closed until further notice.
SH73 at Porters Pass was also closed due to a slip.
Up to 40cm of snow was expected to accumulate above 400 metres in Fiordland, with lesser amounts down to 200m.
The heaviest snow was expected in the area this morning, where between 10cm and 15cm could accumulate in a six-hour period.
Those in Harihari, Westland southwards could expect between 20cm and 30cm of snow to accumulate around 500m, with lesser amounts down to 400m.
There was also a high risk of thunderstorms and hail for Fiordland as a cold, unstable westerly flow continued over the South Island this morning. A moderate risk of thunderstorms was in place for Westland for this afternoon and evening.
However, the weather was expected to gradually ease across the country tomorrow.
Chains are essential on a number of roads in Canterbury and the West Coast, according to the NZ Transport Agency.
Stay up to date with road closures and warnings here.
