Batten down the hatches - meteorologists are warning people to avoid travel as a short but sharp storm approaches parts of the country today.

A heavy rain warning is in force for Westland, Fiordland, the headwaters of Canterbury and Otago Rivers and lakes. A strong wind warning is in force for Canterbury, Marlborough, Wellington, south Wairarapa, Horowhenua-Kapiti Coast, Manawatu, Whanganui and Taranaki south of the mountain.

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

Wellingtonians may be in for a sleepless night with winds gusting up to 140km/h, while parts of the South Island can expect heavy rain, severe gales, and snow.


"If you're an extremely heavy sleeper you might not notice it, otherwise you might want to wear some ear plugs," MetService meteorologist Tom Adams said.

The "fast-moving" weather event is set to hit Fiordland at midday and make it's way up the country, reaching Wellington and other parts of the lower North Island about 10pm.

The storm is expected to be fleeting, with tomorrow's maximum temperature forecast for 18C in Wellington, despite a cold southerly sweeping through overnight. Residents may wake up to a chilly morning, but that should wear off by the afternoon.

Snow could fall as low as 300m in Fiordland.

Adams said there were "so many things going on" that would affect different areas, so people should check MetService to find out what to expect.

"Some of the worst hit places are certainly going to get snow and heavy, strong winds. That's a recipe for trees blowing over, power lines falling down."

Adams said there might be power outages in some parts, and people would want to avoid travel if possible.

"If you don't need to head out, don't."

Other parts of the country would see a "much more milder picture", with scattered showers in Auckland later tonight. The city would still experience gales, but nowhere near the severe gales forecast elsewhere.

"This is a fast-moving system so it will be through in the space of 12 hours or so for most places, but for that same reason it's going to arrive very quickly as well as leave very quickly, so don't get caught out in it."

People should take some time today to secure trampolines or other loose items before the wind arrives this evening.