MetService is forecasting heavy rain for parts of central and northern New Zealand this coming week.

"A slow-moving low pressure system is forecast to lie to the west of New Zealand this week, directing a moist north to northeast flow across the country," says a MetService spokesperson.

"A front embedded in this flow is expected to move eastwards across northern and central New Zealand on Sunday and Monday, delivering a period of heavy rain to many places.

"At this stage, the most rainfall is expected in Northland where an Orange Heavy Rain Warning is now in force, while Heavy Rain Watches are now in effect for northern and eastern parts of Auckland including Great Barrier Island, the Coromandel Peninsula, western Bay
of Plenty, northern Taranaki and northwest Tasman."

People are advised to keep up to date with the latest forecasts in case any changes are made, or further areas are added.

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

The heavy rain warning for Northland is valid for 23 hours from 10am Sunday to 9am Monday and 100 to 140 mm of rain is expected to accumulate, mainly in the north and east, though some localised areas may see larger accumulations. Peak rates of 15 to 25mm per hour, but localised downpours of 25 to 40mm per hour are likely in thunderstorms.