Tropical Cyclone Bune is making its way down to New Zealand and is expected to pass to the east of the country from Wednesday.

The eye of the storm is expected to pass directly over Raoul Island in the Kermadec group tonight, MetService forecasted.

MetService Weather Ambassador Bob McDavitt said Department of Conservation staff on the island have been given warnings of the storms progress since Saturday.

"At present the system has torrential rain and sustained winds of around 110km/h gusting 160km/h near the centre, enough to knock over weak trees and cause minor structural damage," Mr McDavitt said.

Bune is expected to move slowly southwards, out to the east of New Zealand, over the next few days.

On Wednesday heavy rain and a southeast gale may affect the northern Gisborne area, Mr McDavitt said, and there is some chance that these conditions will spread to northern Hawke's Bay on Thursday.

"Long-period swells associated with the system are likely to cause problems," said McDavitt. "Cyclone swells are expected to start arriving on eastern shores from Northland to western Bay of Plenty, and in Gisborne and Hawke's Bay, on Tuesday.

"On Wednesday and possibly also Thursday as well, waves will probably be large enough in some places to pose a danger to swimmers, cause coastal erosion and test the soundness of moorings."

Boat owners along the East Coast are advised to check their moorings beforehand.

- NZ Herald staff