MetService has issued a Severe Thunderstorm Watch for the Waikato, Bay of Plenty and Rotorua regions.

The watch is valid for seven hours from 2pm - 9pm today. 

"Scattered thunderstorms are expected about Bay of Plenty and eastern Waikato this afternoon and evening, bringing localised heavy rain and small hail," a MetService spokesperson said.

"Between 2pm and 9pm a few of the thunderstorms may be severe, producing localised downpours of 25 to 40 mm/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 also be hazardous with surface flooding and poor visibility in heavy rain."

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