Polar blast grounds flights, shuts highways in New Zealand

The North Island capital city of Wellington was lashed by the worst tidal storms in years, with authorities asking some coastal residents to be ready to evacuate, as large swells were forecast over the next 24 hours.

"Those people whose homes have been impacted by past swell and storm events should be prepared for these potential impacts again," regional emergency authorities said in a website statement.

A state of emergency was declared for southern and eastern areas of Wellington. Dozens of flights and ferry services were cancelled, and schools shut.

Hailstorms were reported earlier in the day in Wellington, where the cold winds brought a blanket of snow, as in other South Island cities such as Christchurch, Dunedin and Queenstown.