A heavy rain watch has been issued for Bay of Plenty and Coromandel.

An active front is expected to move over the country during the weekend, bringing heavy rain to northern and western regions, says a MetService spokesperson.

Heavy rain watches are now in force for Northland, Coromandel Peninsula, Bay of Plenty, Mount Taranaki and northwest Tasman.

Bay of Plenty, west of Kawerau, and Coromandel can expect periods of heavy rain and possible thunderstorms between 3am and 6pm on Sunday, with heavy rain expected to ease in Coromandel early Sunday afternoon.

Areas east of Kawerau including Gisborne/Tairawhiti north of Ruatoria can expect the heavy rain and possible thunderstorms between 9am on Sunday and midnight on Monday.

Today and Saturday is looking mostly fine for the region, with a few showers developing in Tauranga Saturday night.