A low pressure system northeast of East Cape is bringing a strong and humid south to southeast flow to Hawke's Bay and Tairawhiti/Gisborne.

Heavy Rain Warnings are in place for those regions, with periods of heavy rain forecast through to Sunday morning.

For Tairawhiti/Gisborne, and the Wairoa District of Hawke's Bay, expect 80 to 100 mm of rain to accumulate in addition to what has already fallen. Peak rates of 10 to 20 mm per hour are forecast with possible thunderstorms.

This warning is valid until 8am on Sunday, November 25.

People are advised to keep up to date with the latest forecasts in case any changes are made. Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

Weather on Sunday

North Island

The forecast for the North Island on Sunday is cloudy in the east with rain and heavy falls for northern Hawkes Bay and Gisborne.

These should be clearing from the south from the afternoon onwards with gusty south to southwesterly winds, says WeatherWatch.

Out west conditions will be drier with a mix of sun and cloud, and one or two isolated showers possible.

Showers about Bay of Plenty may be heavy in the late afternoon and early evening.

South Island

High pressure is bringing mainly settled weather to the South Island on Sunday.

"Mostly sunny, a cool start inland,' says a WeatherWatch spokesperson.

"Foggy to start for the lower South Island. Some high cloud pushes in from the southwest during the course of the afternoon and evening.

"Overnight fog patches may be a little more extensive."