Heavy rain is forecast for the eastern ranges of the Bay of Plenty, with the possibility of thunderstorms and also localised downpours tomorrow afternoon.

The MetService's severe weather watch said there was an active front moving eastwards across southern New Zealand today and central and northern New Zealand on Friday.

This would be accompanied by a period of rain for most places," the MetService said.

The watch is for the possibility that rainfall accumulations could meet warning criteria in Buller from Thursday evening to early Friday morning, and for the eastern ranges of Bay of Plenty from Friday afternoon to overnight Friday


"The heaviest falls were expected in Fiordland and the ranges of Westland where a heavy rain Warning is in force."

This watch also covers the possibility of northwest gales becoming severe today in southern Fiordland, Southland, Otago and Canterbury High Country.

People in these areas are advised to stay up to date with the latest forecast in case parts of this Watch is upgraded to a full warning or further areas are added.