Metservice has warned of heavy rain in the Bay of Plenty, including Rotorua, on Sunday.
Rain is expected to become heavy early in the morning then ease from the west around the middle of Sunday.
In the 12 hours from 2am to 2pm Sunday, expect 80 to 100mm of rain about the ranges, especially east of Whakatane, with 50mm likely about lower lying areas.
A rain warning is also in place for parts of the South Island, with severe northerly gales forecast for parts of central New Zealand, this morning's warning stated.
A deep low is forecast to cross the upper South Island during Sunday, preceded by an active front which is expected to cross much of the country overnight Saturday and Sunday morning.
A period of heavy rain is forecast for Westland, Buller, Nelson, northern Marlborough, Otago, Taranaki and Bay of Plenty during this time.
People in these areas are advised to watch out for rapidly rising rivers and streams and possible slipsand surface flooding.
Gales are expected over much of the country with the passage of the deep low. Severe northerly gales with gusts around 120 km/h are expected from Taranaki to Wellington and the Marlborough Sounds and damaging wind gusts of 140 km/h or more are possible for a time about South Taranaki, Whanganui and Taihape early Sunday morning.
Winds of this strength can cause damage to trees, powerlines and possibly lift
roofs and make driving hazardous.