The central North Island is set to be lashed by severe thunderstorms and hail this afternoon.
The severe weather forecast has been issued by the MetService, which says unstable humid conditions over parts of the country is the culprit.
MetService has issued a severe thunderstorm watch for Rotorua, Bay of Plenty, and Taupo.
These areas could produce localised downpours with intensities of 25 to 40mm per hour and hail of 5 to 15mm in diameter.
MetService said rainfall of this intensity could cause flash flooding especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.
Driving conditions would also be hazardous with surface flooding and poor
visibility in heavy rain.
MetService will continue to monitor the situation closely for severe thunderstorm development and issue further updates.
A severe weather watch is also in place for Fiordland, Dunedin and North Otago.
A front preceded by north-westerly rain is due to move onto the south of the South Island this morning, then moves= slowly northwards over the lower and central South Island during the afternoon and evening.
Meanwhile, a period of southerly rain is forecast for south-eastern parts of the South Island following the passage of the front.