A heavy rain watch is in place for the Bay of Plenty.

The MetService is forecasting heavy rain to move onto the region on Wednesday.

"A low pressure system in the Tasman Sea is expected to move eastwards across New Zealand during Wednesday, bringing rain to much of the country," says the latest update from the weather organisation.

"The heaviest rain is expected over the Tasman District and eastern Bay of Plenty, where Heavy Rain Watches are now in force.

"People are advised to keep up to date with the latest forecasts, in case these are upgraded or further areas are added."

While today and tomorrow are expected to be mostly fine, the MetService says there is a chance for a shower or two before the heaviest rain moves in on Wednesday.

Image: MetService.

Heavy Rain Watch
Area: The eastern ranges of Bay of Plenty
Valid: 15 hours from 9:00am Wed 15 May to 12:00am Thu 16 May
Forecast: A period of heavy rain, and amounts may approach warning criteria.

Area: Tasman about and west of Motueka
Valid: 13 hours from 4:00am Wed 15 May to 5:00pm Wed 15 May
Forecast: A period of heavy rain, and amounts may approach warning criteria.