MetService has issued a severe thunderstorm watch for Hawkes' Bay, as well as parts of the lower North Island and South Island.

A squall line with embedded thunderstorms is forecast to move north over the area about the Mahia Peninsula this evening.

Due to the fast moving nature of this line and the embedded storms, there is a risk of severe thunderstorms with damaging wind gusts of around 130 km/h.

The severe thunderstorm watch for Gisborne and Hawkes' Bay is valid for seven hours from 5pm, Monday, August 12, to 12am, Tuesday, August 13.

A severe thunderstorm watch has also been issued for Tararua, Wairarapa, Wellington, Marlborough, Canterbury Plains, and Canterbury High Country.

This is valid for six hours, 17 minutes from 12.43pm - 7pm, Monday August 12.

A squall line with embedded thunderstorms is moving north over the north of Canterbury, the east coast of Marlborough, Wellington and Wairarapa this afternoon.

Due to the fast moving nature of this line and the embedded storms, there is a risk of severe thunderstorms with damaging wind gusts of around 130 km/h.

Wind gusts of this strength can cause some structural damage, including trees and power lines, and may make driving hazardous. 

A Severe Thunderstorm Watch means conditions are favourable for severe thunderstorms in and close to the watch area. People in these areas should be on the lookout for threatening weather conditions and monitor for possible Severe Thunderstorm Warnings. 

For information on preparing for and keeping safe during a storm, see the Civil Defence Get Ready website.