Weather: Animation shows 'damaging' Cyclone Uesi 'taking aim' at South Island

Cyclone Uesi remains on track to hit the South Island and forecasters have predicted exactly how it will arrive.

The severe category 3 cyclone is moving into the Tasman Sea area on Wednesday and could sweep Fiordland and the West Coast with flooding, winds and thunderstorms forecast.

"This system doesn't reach NZ until Sunday," MetService says. 

"Severe weather is still expected, particularly for southern South Island, still recovering from recent storms."

WeatherWatch has released a new animation of the cyclone "taking aim" at the South Island on Sunday and Monday.

"Monday looks to be the windiest but damaging winds look limited with hurricane-force winds mainly at sea and not over land," the forecaster said in a statement.

"This may change so keep up to date with any Government funded warnings at MetService and of course our latest news, video and map updates."

Between 125 and 150mm of rain is forecast in the western South Island, WeatherWatch warns.

NIWA says the details and location of the cyclone may change as it approaches.

Civil Defence Southland controller Angus McKay told Newshub they are anxious about it but it should be manageable.

Local authorities are doing everything they can to prepare for the event, he said.

In a statement, NZ Transport Agency system manager Graeme Hall said it would be working closely with Emergency Management Southland until next Tuesday.

State Highway 94 to Milford Sound remains closed to all but emergency vehicles following last week's flooding.

"We are doing our best to provide a safe route for all road users and restore this important link to Milford," Hall said.