Metservice issues severe thunderstorm watch for Clutha and Southland 

The Metservice has issued a severe thunderstorm watch for Clutha and Southland for Thursday afternoon.

The forecaster says thunderstorms are expected to develop over the southern half of the South Island this afternoon and evening, bringing heavy rain with intensities of 15 to 25mm/h and hail 10 to 20mm in diameter.

It says there is a risk some thunderstorms could become slow moving and severe, producing localised downpours of 25 to 40mm/h.

Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips. Driving conditions will be hazardous with surface flooding and poor visibility in heavy rain, the forecaster says.

READ MORE:
* Southland hit by 1130 lightning strikes
* Nearly 1700 lightning strikes across NZ, more than 1100 in Southland alone

Metservice duty forecaster Lewis Ferris said residents should keep an eye on the sky during the afternoon to see where thunderstorms were developing.

“There will be some places that see heavy rain and some will get absolutely nothing.

“You’ll see those big tall convection clouds caused by convection heating up during the hottest part of the day.’’

Conditions were likely to be the same on Friday.

“Broadly speaking we might also see some action on Saturday, but by the time Sunday comes along things will settle down as that muggy weather is replaced by cooler temperatures.”

On Saturday, businesses in Gore and Winton were damaged after heavy rain fell in the area.

A Gore District Council spokesperson said: “we appreciate the prospect of another downpour like Saturday will be of concern to businesses impacted at the weekend.

“The Council has advised its contractors about the weather watch, Staff will be monitoring the situation closely and will be in a position to respond quickly should the severe thunderstorm hit.’’