Snow, ice and wind wipe out summer

The country's Indian summer was blasted away at the weekend as a cold front swept up New Zealand.

Snow covered the Desert Rd, a 71-year-old yachtsman had to be winched to safety from a boat off Stewart Island, and an Interislander ferry carrying 676 passengers lost power in 4m swells near the entrance to Tory Channel in the Marlborough Sounds, where the MetService said winds reached 75km/h.

Last night the agency said swells in Cook Strait were bigger still at 8.3m. The Arahura took seven hours to complete the crossing, almost twice as long as usual.

The Maritime Safety Authority is investigating the breakdown. It had put emergency services - including the Rescue Co-ordination Centre and the Westpac rescue helicopter - on standby after the captain issued a "pan-pan", a call indicating a potentially serious situation, as it headed into the channel.

Marble-sized hailstones fell in Christchurch, turning the city white.

Temperatures dived from a balmy 19C on Saturday afternoon to just 4C by evening, rising yesterday to a high of 8C.

And the weather is likely to get worse.

The MetService issued strong wind warnings across the South Island and parts of the lower North Island, and four snow warnings for the central and lower North Island.

Snow was expected to affect many lower and central North Island roads overnight, including the Desert Rd, State Highway 1 north of Hunterville and the Gentle Annie and Napier-Taupo roads.

A further 15 gale and storm warnings were issued for marine areas, with Canterbury told to expect heavy thundery showers and more hail.

The blustery conditions were expected to move on to the lower North Island last night and spread up the east coast to Gisborne.

Bob McDavitt of MetService said the cold snap would sweep across the country, also bringing showers to much of Auckland and Northland.

But the good news was that a break in the rain was predicted in time for Anzac Day dawn memorial services, he said.

Some showers would linger between Wellington and Napier, but dawn ceremonies elsewhere were likely to be held under crisp, clear skies and cool temperatures.

"It'll be frosty in the south and near the mountains, and between 7C and 10C around the North Island coast. An extra layer of clothing will be the first order of the day," Mr McDavitt said.

Wellington police were last night advising people against driving unless "absolutely necessary".

"Strong wind gusts, lightning and thunder is affecting most parts of Wellington," they said.

Heavy snow fell yesterday on the Port Hills near Christchurch, and one car was reported stuck on Gebbies Pass Rd on Banks Peninsula.

Police rescued the occupants but the car had to be left behind, said Inspector John Doherty.

"The hail was the size of marbles but there have been no reports of damage," he said.

Hail first began falling in Christchurch on Saturday night, but continued throughout yesterday.

Temperatures in Queenstown fell to minus 2 degrees over Saturday night, and locals woke to find new snow blanketing the town.

In Dunedin, police were forced to close the city's northern motorway for several hours.

A 71-year-old yachtsman, airlifted from his vessel near Stewart Island, was flown to Southland Hospital in Invercargill but released last night.

Meanwhile in Northland about 10pm a rescue helicopter was sent to a mayday call from a 30m yacht in trouble off Ninety Mile Beach.

A Martime Safety Authority spokesman said there was one man on board and the yacht was taking on water.