The MetService has issued a severe weather watch for the Coromandel Peninsula and the western Bay of Plenty.

The forecast is for periods of heavy rain about Coromandel Peninsula and western Bay of Plenty from Monday afternoon to Tuesday.

A low over the north Tasman Sea will move on to the North Island Sunday night, and over the North Island late Monday and on Tuesday. The low should bring periods of heavy rain with isolated thunderstorms to the northern parts of the North Island.

The heaviest falls are expected about Coromandel Peninsula and Bay of Plenty west of Te Puke from Monday afternoon to Tuesday evening, and a Heavy Rain Watch is now in force for these regions.

People are advised to keep up to date with the latest forecasts in case this watch is upgraded to a full warning or further areas are added.

The Heavy Rain Watch for the Coromandel Peninsula and the Bay of Plenty west of Te Puke is valid for 27 hours from 3pm Monday to 6pm Tuesday.

Periods of heavy rain are forecast during this time and rainfall amounts may approach warning criteria during, with possible thunderstorms.

An update for severe weather will be issued by the MetService by 9pm on Sunday.