Cold night across the country, frosty start for many Wednesday; heavy snow on the way for south, may reach lower and central North Island

Most of the country is in for a cold start on Wednesday, with frosts in many places.

Weather conditions had generally improved on Tuesday, but temperatures could drop away quickly overnight in areas with clearer skies, MetService meteorologist John Law said.

That included Central North Island areas such as Taupō and Rotorua, while temperatures would be below freezing in many central parts of the South Island.

“A cold and frosty morning for pretty much most of us, as we start the day tomorrow,” Law said.

After the cold start, a band of wet, snowy weather “with a real wintry feel to it” would push onto the southwest of the country.

MetService is forecasting temperatures to drop to 2C in Hamilton, 3C in Wellington and -2C in Christchurch.

Central Auckland is expected to have a small amount of wind overnight. It won’t be much but will be enough to keep the city warmer than most of the rest of the country, and prevent the temperature dropping below 8C. Slightly to the south, Pukekohe is forecast to get down to 4C.

While the 3C forecast for Wellington is low for the downtown area, it will still be considerably warmer than Upper Hutt, which is forecast to have a low of -3C. After a fine morning in the capital, showers are expected in the afternoon, with rain at night.

Conditions are also expected to deteriorate in Christchurch, from a fine start with a -2C low, to rain from afternoon falling as snow above 300m.

In the North Island, Wednesday would start with dry, clear, frosty conditions in the Bay of Plenty, and down through the eastern regions, Law said.

Cloud would thicken up during the daytime, and by the end of Wednesday, heading into the night, wet weather would be pushing in from the west.

MetService expects the east of the North Island – from Coromandel Peninsula to Hawke’s Bay, and including Taumarunui and Taupō – to have the best weather in the country on Wednesday with mainly fine conditions.

While most of the heavy and low snow is expected in the South Island – starting Wednesday morning in the south, continuing into early Thursday in the north – there’s also a chance of heavy snow in the North Island on Thursday.

In the lower North Island, snow could fall to 600m in Wairarapa and Wellington on Thursday, MetService said. It had low confidence of heavy snow on Thursday in the Tararua and Remutaka ranges, and in parts of Wellington above 600m.

There was also low confidence of heavy snow in the Central North Island High Country above 700m on Thursday, affecting the Desert Road.

In the South Island, heaviest falls are forecast for northern inland Canterbury, southern Marlborough and Nelson Lakes National Park.

Up to 30cm could fall in that area above 300m overnight Wednesday into Thursday morning, with some snow falling as low as 100m.

For Dunedin, MetService is forecasting showers to fall as snow down to 200m on Wednesday afternoon, and southwesterlies could be strong.

It was possible 1-2cm of snow could settle on the summit of the Dunedin to Waitati Highway – SH1 – at times during Wednesday, MetService said.

It also warned that as much as 25cm of snow could settle overnight Wednesday on the summits of Lewis Pass, Arthur’s Pass and Porters Pass.

Haast Pass had a chance of some snow from 9am to 1pm Wednesday, and snow could settle during Wednesday on Lindis Pass, the Crown Range Rd, and the Milford Road.

Snow could fall during Wednesday down to 200m, and could be heavy above 400m, in Southland, Fiordland, and in Otago south of a line from Queenstown to Mosgiel, MetService said.

Heavy and low snow was also possible in inland Canterbury south of Arthur’s Pass from Wednesday afternoon into the night, and from late night Wednesday into Thursday morning in Buller and western parts of Tasman.