Heavy rain is on the cards for parts of the Bay of Plenty today.

The MetService has issued a heavy rain watch for the region.

"A broad low pressure system lying just west of New Zealand is expected to extend across central areas overnight, bringing periods of heavy rain," says the weather organisation.

"A second low then deepens to the west during Monday, allowing the rain to ease in most places."

The heavy rain watch covers northern Buller, the remainder of Nelson, and northwestern parts of Marlborough, Tongariro National Park and the Kaimanawa Range, Tararua Range and the ranges of eastern Bay of Plenty.

"People are advised to keep up to date with the latest forecasts in case part of this Watch is upgraded to a Warning, or further areas are added."

The watch is valid for 12 hours from 1am to 1pm today.

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