Heavy rain is being forecast for the Bay of Plenty region.

The MetService has issued a severe weather watch for heavy rain for the 12 hours starting 12pm on Tuesday.

'A low over the Tasman Sea moves across central New Zealand tomorrow, bringing rain to many areas,” says the weather organisation.

'An associated front brings a period of heavy northerly rain to exposed regions from Buller to East Cape.

'Meanwhile, as the low approaches and crosses central New Zealand a period of southeasterly rain is forecast for eastern parts of the South Island.

'People are advised to keep up to date with forecasts as some areas on watch may be upgraded to a warning, and additional areas may be placed on watch.

Heavy Rain Watch

Area: Bay of Plenty and the ranges of Gisborne
Valid: 12 hours from 2pm Tuesday to 2am Wednesday
Forecast: A period of heavy northerly rain, with thunderstorms possible. Amounts may approach warning criteria, especially about the ranges of eastern Bay of Plenty and the ranges of Gisborne.

Area: The central high country between Taranaki and Bay of Plenty
Valid: 12 hours from 12pm Tuesday to 12am Wednesday
Forecast: A period of heavy northerly rain, with thunderstorms possible. Amounts may approach warning criteria, mainly about higher ground.

Area: North Taranaki
Valid: 24 hours from 6pm Monday to 6pm Tuesday
Forecast: Periods of heavy northerly rain with thunderstorms possible, mainly this evening and Tuesday afternoon. Amounts may approach warning criteria. Note: A warning is in force for the Mountain.

Area: Buller
Valid: 24 hours from 4pm Monday to 4pm Tuesday
Forecast: Periods of heavy northerly rain, and amounts may approach warning criteria, especially about the ranges.

Area: Canterbury High Country, Canterbury Plains south of the Rakaia River, and the ranges of Westland
Valid: 21 hours from 7am Tuesday to 4am Wednesday
Forecast: Southeasterly rain, heavy at times, and amounts may approach warning criteria.

Area: North Otago
Valid: 12 hours from 1pm Tuesday to 1am Wednesday
Forecast: Southeasterly rain, heavy at times, and amounts may approach warning criteria.