A severe tropical cyclone is expected to start battering New Zealand later today, but is likely to brush the coastline rather than striking major centres.
WeatherWatch.co.nz head weather analyst Philip Duncan said Cyclone Wilma would be more severe than last weekend's sub-tropical low, which coincided with a king tide, causing flooding in coastal areas of Auckland.
High seas were already forming around the northeast coast, and campers and residents in the upper North Island were being warned to prepare for severe weather including gales and torrential rain.
Cyclone Wilma formed east of Samoa last Saturday and passed over Tonga on Tuesday, causing damage to resorts and crops but, like last week's two cyclones, its strength was expected to decrease by the time it reached New Zealand.
Mr Duncan said the storm would be severe as it passed near the upper North Island, regardless of whether it was downgraded from a cyclone.
"We're talking sustained winds of at least 80kmh to 100kmh near the centre and gusts over 150kmh.
"The only thing working for North Islanders is the fact that the low looks likely to brush our coastline rather than a direct hit on somewhere like Auckland."
The cyclone would pass near the Bay of Islands tomorrow morning, tracking 200km from downtown Auckland.
"If it maintains category 1 strength it could make for damaging winds in Northland, Auckland, Coromandel and particularly eastern Waikato, where gusts may be even higher due to the geography of the Kaimais and Mt Te Aroha," Mr Duncan said.
He said the cyclone was "like dropping a large rock into a pond".
"The ripple effect will spread into places like eastern Northland, eastern Coromandel Peninsula and Bay of Plenty.
"The seas are going to be incredibly dangerous and we're advising even the keenest of surfers to stay out of the sea on Saturday."
There was no need to panic, but people should be prepared for "worst case scenarios" like road closures, power cuts and minor damage to trees and weak structures.
