A severe weather watch has been issued for the Bay of Plenty and Coromandel, with possible heavy rains to strike both regions on Sunday and Monday.

MetService says a slow-moving low in the Tasman Sea will direct a moist northeasterly flow over New Zealand during the weekend and on Monday.

'Rainbands embedded within the flow are likely to bring periods of heavy rain with possible thunderstorms to the northern half of the North Island.”

In the Bay of Plenty and Rotorua, periods of heavy rain and possible thunderstorms are likely from Sunday afternoon through to Monday afternoon, with the heaviest falls likely on Monday.

While on the Coromandel, periods of heavy rain with possible thunderstorms are expected Sunday afternoon through to Monday morning, with the heaviest falls likely overnight Sunday and Monday morning.

Keep up to date with the latest forecasts and any watches/warnings at metservice.com or on mobile devices at m.metservice.com.

You can also follow updates on MetService TV, on Facebook, @metservice and @MetServiceWARN on Twitter and at blog.metservice.com