Snow surrounding the Shotover River in Queenstown.
.
The low stretches from just south of Fiji to Antarctica's ice shelf, but only 20 per cent of the storm is affecting New Zealand.
WeatherWatch.co.nz said the forecast
air pressure at its centre over the next 24 hours would be greater than that of Hurricane Katrina when it made landfall in 2005.
Weather expert Philip Duncan said, "It's fairly normal to get a cold snap in late May. We're less than a week away from winter, it's not surprising to get a blast like this."
But he said
the low's strength was surprising.
"
The depth of this storm south of New Zealand is up there with some of the biggest hurricanes we've seen. It's a really big storm."
However, WeatherWatch.co.nz said only the
storm's edges were affecting New Zealand - its centre lay around 1000 to 1500kms to our south east.
Southland, Otago and Banks Peninsula woke this morning to the heaviest dumping of snow so far this year.
Overnight, areas of Central Otago and Southland saw up to 30 cm of snow, according to Metservice.
The North Island didn't escape the cold weather with light snow falls reported in Napier and heavier falls on the Napier-Taupo Rd.
Queenstown Airport was temporarily closed, with heavy snow right down to the township, and snow flurries blanketed Invercargill.
Dunedin was battered by an onslaught of nasty weather, said MetService, hit by snow, showers and offshore thunderstorms.
© Petra BalsillieArrowtown blanketed in snow.
Comment: Dangerous Flood Threat to Persist in Texas, Southern Plains