MetService is issuing a rain warning for the Coromandel and the Bay of Plenty west of Matata.

This comes as a subtropical low continues to bring heavy rain to parts of northern and central New Zealand.

"A slow-moving subtropical low over the Tasman Sea directs a moist northeast flow over northern and central New Zealand, bringing warning amounts of rain to some places," says a MetService spokesperson.

"Heavy rain could cause slips, surface flooding and damage to roads.

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

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

Area: Coromandel Peninsula
Valid: 5 hours from 8.00pm Fri 6 Jan to 1.00am Sat 7 Jan
Forecast: "Expect a further 20 to 40 mm of rain to accumulate on top of what has already fallen, mainly about the ranges. Peak rates of about 10 mm/h about the ranges."

Area: Bay of Plenty west of Matata and north of Rotorua
Valid: 7 hours from 8.00pm Fri 6 Jan to 3.00am Sat 7 Jan
Forecast: "Expect a further 30 to 50 mm of rain to accumulate inland on top of what has already fallen, especially about the Kaimai Range, with lesser amounts elsewhere."

Area: Tasman west of Motueka
Valid: 8 hours from 8.00pm Fri 6 Jan to 4.00am Sat 7 Jan
Forecast: "Expect 40 to 60 mm of rain to accumulate on top of what has already fallen, mainly about the ranges. Peak rates of 10 to 15 mm/h."

Heavy Rain Watch
Area: Bay of Plenty from Matata eastwards, also Gisborne north of Ruatoria
Valid: 10 hours from 8.00pm Fri 6 Jan to 6.00am Sat 7 Jan
Forecast: "Periods of heavy rain, and rainfall amounts may approach warning criteria, mainly inland."