Cyclone Uesi edges closer, Southland braces for more flooding

Southland is preparing for the possibility of more flooding with Cyclone Uesi set to hit the region over the weekend.

On Thursday the storm was downgraded to an extra-tropical cyclone, but forecasters say "it could still pack a punch".

It is expected to make landfall in the South Island from late Saturday, bringing heavy rain and strong to gale force winds on Sunday into Monday.

Ellyse Gore, Otago Regional Council's duty flood officer, says the exact impact the storm will have is unclear, but people in Southland need to be ready. 

"We will potentially see significant rainfall amounts in the same areas that were affected by weather last week, which could mean impacts to our lake levels as they are already high" Gore told Newshub.  

Last week torrential rain caused severe flooding in Southland, damaging houses and putting a strain on businesses in what should be their peak season.

Nearly 6000 people were evacuated from their homes across Southland, with Gore and Mataura hit the hardest. 

Hundreds of tourists were also stranded in Fiordland after flooding damaged State Highway 94 and cut off access to the Milford area.

Gore says officials are keeping a close eye on the situation.

"We know that it's coming, we know it could potentially be significant, but there's uncertainty around that."

Emergency Management Southland was warning farmers in the region to be prepared.

"With soil moisture levels already very high following the flooding last week, farmers in particular need to be prepared and keep a watch on their local waterways and stock," it wrote on its Facebook page.

"We have the state of emergency for Southland still in place and the team at the emergency coordination centre are watching and preparing should the predicted rainfall arrive."

The MetService predicts the deep low will be felt most in Westland and Fiordland, though there was a chance there could be a "significant impact" in Southland and Otago, in addition to the west of the South Island. 

There was a moderate chance of "warning amounts of rain"  in Fiordland, Southland and Otago, MetService said, adding they had "high confidence" of heavy rain in Westland, with that expected to spread across to the headwaters of Canterbury lakes and rivers on Sunday and Monday. 

A map showing Weatherwatch's forecast for Uesi on Sunday night.
A map showing Weatherwatch's forecast for Uesi on Sunday night. Photo credit: WeatherWatch

Despite being downgraded from a tropical cyclone, Uesi "could still pack a punch", forecasters from WeatherWatch said.

Head forecaster Philip Duncan said the technical change helps "unwind" the tightly packed centre of the storm.

"The centre of the cyclone switches from a perfect circle to a more egg-shaped low, while the tightly packed isobars around it spread out further," Duncan said.

"But extra-tropical storms are well known for becoming even bigger than their tropical alter ego".

Duncan said Uesi was "still a very serious storm" and that its remnants may well linger from Sunday to Wednesday before high pressure returns.