Weather: Severe thunderstorm warning for parts of North Island, torrential rain and hail possible

Thunderstorms with torrential rain and hail could hit parts of South Waikato, Taupō and Rotorua on Wednesday afternoon, MetService is warning.

At 1:37pm, MetService detected severe thunderstorms near Tīrau in South Waikato, moving southeast.

The thunderstorms are expected to be accompanied by torrential rain and hail.

That rain and hail could cause surface and flash flooding around streams and urban areas, and make driving conditions dangerous.

Elsewhere in the North Island, a severe thunderstorm watch is also in effect for areas including Auckland, Coromandel Peninsula, and Bay of Plenty. It applies from 2pm-7.30pm on Wednesday.

"For eastern Auckland, inland parts of Waikato, inland parts of Bay of Plenty west of Te Puke including Rotorua and northern Taupo, there is a moderate risk of severe thunderstorms with localised downpours of 25-40 mm per hour," MetService said.

In the South Island, a severe thunderstorm watch is in effect for Dunedin, Clutha, and Southland. It applies until 7pm on Wednesday.

"For southern Southland, and inland parts of Clutha and Dunedin, there is a moderate risk of severe thunderstorms with localised downpours of 25-40 mm per hour," MetService said.

There is also an orange heavy rain warning in place for Bay of Plenty east of Opotiki, as well as the ranges of Gisborne and Tairawhiti, north of Tokomaru Bay. It's in effect until 5pm on Wednesday.

"We've still got this band of rainfall across the eastern side, and as we head through the afternoon we'll find the return of more showers, some heavy and thundery," meteorologist John Law said.

Down south, a heavy rain watch also applies for the ranges of Westland District near Mt Cook until 9pm on Wednesday.