A winter storm set to bring heavy rain and gales to much of the country has started baring its teeth down south.
MetService severe weather forecaster Erick Brenstrum said rain has already started falling in Fiordland around Milford Sound, and would only get heavier over the next couple of hours.
"We're expecting the heavy rain from about 9pm onwards tonight. It's all yet to come," he said.
"As far as we can tell it's on track to be pretty much what we said it would this morning."
The New Zealand Transport Agency website warned SH94 from the Hollyford Tunnel to Milford Sound would be closed overnight due to heavy rain, and would reopen tomorrow dependent on conditions.
MetService earlier warned a nasty trough was waiting over the Tasman Sea, set to hit the South Island's West Coast tonight and move its way over the rest of the country tomorrow.
Heavy rain was expected overnight Tuesday and during Wednesday for Mt Taranaki, the western ranges of Nelson, Buller, Westland, Fiordland, Canterbury headwaters and for Otago's lakes and rivers.
MetService warned the rain could lead to rapidly rising rivers and streams, and cause slips and surface flooding.
Severe northerly gales were forecast to hit inland Canterbury tonight, moving north to wreak havoc over the Cook Strait tomorrow. The severe winds would particularly affect the Marlborough Sounds and Wellington, and could pose a hazard for motorists.
Even Aucklanders would see a bit of the action, with strong northeasterlies forecast for tomorrow.
Residents in the city of sails can expect a high tomorrow of 18 degrees and an overnight low of 15.