Forecasters have warned people in parts of the North Island to prepare for severe thunderstorms and rain.
Photo: Supplied/ MetService

Severe thunderstorms and heavy rain could be on the way for many areas of the North Island, MetService says.

The warnings and watches cover many regions, including Wellington, Auckland, Northland, Great Barrier Island, Coromandel, the Bay of Plenty and Rotorua.

Residents in the Wellington and Wairarapa had been warned to stay inside and away from windows, with heavy thunderstorms set to batter the region.

MetService issued a severe thunderstorm warning for Wellington City, Hutt City and South Wairarapa, after detecting severe storms near offshore Mana Island and near Wellington Airport.

The bad weather was expected to rest near Wellington, Porirua, Wellington’s south coast, Palliser Bay and Baring Head, moving later to the southern Remutaka Ranges.

Heavy rain and hail had also been forecast, and residents are being encouraged to keep indoors and check that drains are cleared.

Meanwhile, MetService meteorologist Ngaire Wotherspoon said Northland, Auckland, Coromandel and the Bay of Plenty down to north of Gisborne should be prepared for downpours.

Forecasters issued a watch notice for the period from 6pm Sunday to midnight, due to an unstable northwest airflow.

Downfalls between 25 and 40 millimetres per hour were forecast, with a risk of hail and a low risk of tornadoes, she said.

Rainfall of this intensity could cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and might also lead to slips, the MetService notice said.

It urged people to plan ahead, and be vigilant for changing or threatening conditions; and to stay updated on weather warnings.

“Driving conditions will also be hazardous, with surface flooding and poor visibility in heavy rain.”

The weather was expected to ease after 10pm for areas in the north.

Advice about how to prepare for a storm can be found here.