A severe thunderstorm watch is now in force for the Bay of Plenty.

The MetService is expecting scattered thunderstorms over many North Island areas from Northland to Manawatu and northern Wairarapa this afternoon and evening.

"Between 3pm and 10pm today, a few of the thunderstorms could be severe with localised downpours of 20-40mm/h and hail," says a spokesperson for the weather organisation.

"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 also be hazardous with surface flooding and poor visibility in heavy rain.
The thunderstorm activity should ease late evening."

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."

Area: Northland, Auckland, Waikato, Waitomo, Taumarunui, Bay of Plenty, Rotorua, Taupo, Hawke's Bay, Taihape, Wanganui, Manawatu, Tararua, Wairarapa
Valid: 7 hours 8 minutes from 2:52pm Sat 10 Dec to 10pm Sat 10 Dec