Dig out those winter woollies

Much of the North Island was waking shivering this morning as a severe cold snap moved up the country. 

The cold front has moved north, bringing with it snow, hail and sleet.

State Highway 1 over the Desert Rd and State Highway 49 between Ohakune and Waiouru were closed.

MetService severe weather forecaster Erick Brenstrum said 30cm to 40cm of snow would fall to 600m across the central North Island and high country, from inland Taranaki to Taihape, while lower areas could expect up to 20cm.

"It's a significant event because it's the greatest quantity we've had for quite some time. It's possibly the worst snow event of the winter, but it's not winter, it's spring," Mr Brenstrum said.

"It may well be there are some farmers who have some trouble as well."

Auckland was lashed by hail and thunderstorms throughout the day.

The front will be gone as quickly as it came, however. Mr Brenstrum said that by this afternoon there would only be some showers left over the top of the North Island.

Yesterday, Christchurch was paralysed under 5cm to 10cm of snow, delaying flights, shutting down public transport, closing schools and affecting electricity supplies.

MetService lead forecaster Andy Downs said it was not unusual to get snow at this time of year, but because spring had come so early, the warmer temperatures had lulled people into thinking winter was over.

"We've had such a mild winter people weren't predicting it."

In Wellington, a tug had to help the Interisland Line's new ferry, Kaitaki, to berth when strong southerlies hit during the afternoon.

Snow was forecast to fall to 300m around Wanganui, Manawatu and through to Taihape, Mr Downs said.

"By the morning there should be a nice big covering of snow all over the place."

He said some North Island high country farmers had got off easy so far this winter, but with heavy snow falls and bitter winds predicted the situation could get worse.

The heavy falls have had their upside, however, helping to set up Turoa and Whakapapa skifields for the school holidays next week.

"It's snowing quite heavily here now," Turoa area manager Chris Thrupp said yesterday.

"It means we can offer a terrific facility for the school holidays."

He said the skifield operators had been getting nervous, with the lower mountain base wearing thin and temperatures of up to 16C.

Whakapapa marketing manager Mark Smith said Whakapapa had remained open even on the lower fields but it was "hard work".

National Institute of Water and Atmospheric Research scientist Jim Salinger said the cold snap was unusual coming during such mild weather.

"You'd have to go back to about 1995 to find a similar one," Dr Salinger said.

Average temperatures plummeted. Christchurch recorded 3C at 3pm yesterday, whereas the average would normally have been about 15C.

In Auckland it was 9C - it would normally be about 16C - and in Waiouru it was zero instead of about 10C.