A heavy rain and thunderstorm watch is in force for the Bay of Plenty and Rotorua.
MetService said thunderstorms were likely and would bring heavy rain or showers, strong winds gusting 100 km/h, hail and the risk of a small tornado.
There was also a moderate risk that a few of these thunderstorms could become severe producing damaging winds of 110 km/h or stronger or a damaging tornado.
Wind gusts of this strength could cause some structural damage, including trees
and power lines, and may make driving hazardous.
If any tornados occurred, they would only affect very localised areas.
MetService said 50mm of rain could fall in areas east of Whakatane from 10pm tonight to 4am Monday morning.
Rotorua can expect a few showers to develop this afternoon, turning to rain this evening with the chance of heavy falls.
Showers with some possibly heavy and thundery are forecast for tomorrow.