Heavy rain's expected across the top of the North Island today

A low pressure system is forecast to move eastwards across northern New Zealand - bringing bands of rain, which are likely to be heavy in some areas.

Heavy rain watches are in place for Northland, Auckland, Coromandel Peninsula, Waikato and Gisborne.

MetService Meteorologist Aluuyn Bakker says Orange Heavy Rain Warnings are in place for the Bay of Plenty, through till midnight.

He says there are thunderstorms expected through the region as well - with peak rain rates of 25 to 40 millimetres in localised downpours.