A heavy rain watch issued for the Bay of Plenty is being upgraded to a warning.

A severe weather warning also remains in force for the Coromandel area.

'A low is expected to move slowly southwards and over northern New Zealand during Friday from the subtropics, bringing significant amounts of rain and gale east to southeasterly winds to parts of the North Island,” says a MetService spokesperson.

'A Heavy Rain Warning is in force for Coromandel Peninsula, and now including Bay of Plenty and Gisborne, while Watches for heavy rain and strong east to southeasterlies are in force for some other parts of the North Island.

'People are advised to keep up to date with the latest forecasts in case any changes are made, or more 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: 20 hours from 1am Fri 11 Nov to 9pm Fri 11 Nov
Forecast: Expect 130 to 180 mm of rain about the ranges, but 70 to 120 mm near the coast. Peak rates of 15 to 25 mm/h about the ranges during Friday afternoon and early evening.

Area: Bay of Plenty including Rotorua
Valid: 18 hours from 9am Fri 11 Nov to 3am Sat 12 Nov
Forecast: Expect 90 to 140 mm of rain to accumulate, especially west of Kawerau and the ranges east of Opotiki. Peak rates of 15 to 25 mm/h expected during Friday afternoon and evening.

Area: Gisborne
Valid: 22 hours from 5am Fri 11 Nov to 3am Sat 12 Nov
Forecast: Expect 140 to 200 mm of rain or more about the ranges north of Tolaga Bay, with lesser amounts elsewhere. Peak rates of 20 to 30 mm/h about the ranges, especially north of Tolaga Bay from Friday afternoon.

Heavy Rain Watch

Area: Northland
Valid: 19 hours from 9pm Thu 10 Nov to 4pm Fri 11 Nov
Forecast: Periods of heavy rain, with thunderstorms possible during Friday afternoon. Rainfall amounts may exceed warning criteria.

Area: Auckland north of Takapuna, including Great Barrier Island
Valid: 18 hours from 12am Fri 11 Nov to 6pm Fri 11 Nov
Forecast: Periods of heavy rain, with thunderstorms possible Friday afternoon. Rainfall amounts may reach warning criteria.

Area: The ranges of Hawke's Bay, including eastern hills south of Hastings
Valid: 15 hours from 10am Fri 11 Nov to 1am Sat 12 Nov
Forecast: Periods of heavy rain. Rainfall amounts may exceed warning criteria.
Note: Heavy Rain about the ranges north Hastings is expected to ease around midday Thursday, and a Watch for a new period of heavy rain during tomorrow.

Strong Wind Watch

Area: Northland from Bay of Islands southwards
Valid: 15 hours from 9pm Thu 10 Nov to 12pm Fri 11 Nov
Forecast: East to southeast winds may approach severe gale in exposed places.

Area: Auckland from the Harbour Bridge northwards, also Great Barrier Island and Coromandel Peninsula
Valid: 22 hours from 6pm Thu 10 Nov to 4pm Fri 11 Nov
Forecast: East to southeast winds may approach severe gale in exposed places.

Area: Bay of Plenty east of Whakatane and Taupo east of the Lake
Valid: 32 hours from 9am Thu 10 Nov to 5pm Fri 11 Nov
Forecast: East to southeast winds may reach severe gale in exposed places.

Area: Manawatu and Horowhenua
Valid: 10 hours from 12pm Fri 11 Nov to 10pm Fri 11 Nov
Forecast: Easterly winds may approach severe gale in exposed places.