KEY POINTS:
Wild weather which lashed the Wellington region over the past two days is now causing chaos further north.
After a thunderstorm cut power to about 40,000 homes on the Kapiti Coast, Porirua and the Hutt Valley overnight, heavy rain and wind hit the capital today.
Surface flooding in Petone caused delays for drivers on State Highway 2, and in Raumati five shops were flooded, Fire Service communications manager Murray Dunbar said.
Wellington firefighters responded to about a dozen calls, he said, mostly involving trees and power lines coming down.
Four or five roofs lifted but none came off, and there were no reports of anyone injured or major damage to property.
"It certainly wasn't what we'd call extremely busy, we've had incidents of weather that have been far worse than that," Mr Dunbar said.
The police said driving wind and rain were creating hazardous driving conditions on the Kapiti Coast and visibility is down to 25 metres in some areas.
Neither ferry crossings, nor flights have been affected by the conditions.
Inspector Ian Brooker of the police northern communications centre said Waikato was getting a battering from the winds this evening.
One woman was taken to hospital in Hamilton with critical injuries after a tree fell on her near the intersection of Ruakura Rd and Silverdale Rd near Waikato University.
He said there had been several reports of trees and power lines being down.
Strong winds were also affecting parts of Auckland, with a number of people without power since 3pm, mostly in the North Shore and Rodney districts.
Vector Energy spokeswoman Phillipa White said about 7000 customers were without power in parts of Waitoki, Kaukapakapa, South Head, Hobsonville and Mairangi Bay.
A fire communications centre spokeswoman said there were several reports of tiles flying in parts of Auckland, with west Auckland particularly hard-hit.
A coastguard spokeswoman said winds had hit up to 68 knots on Manukau Harbour and 55 knots on Waitemata Harbour but the seas were relatively calm and boats were at this stage secure.
Two container terminals at Auckland's port have been closed down due to safety concerns, after winds reached 45 knots. Port law forbids the operation of the terminals if the wind gusts over 38 knots.
This afternoon's rough weather followed a short, sharp storm in Auckland last night, with thunder, lightning and squalls in many areas and winds reported up to 120km/h on the Hauraki Gulf.
Downed trees affected power supplies in some parts of greater Auckland, and there was one report of a trampoline sent flying by wind in Henderson.
Metservice spokesman Bob McDavitt said the stormy conditions were the third part of a three-part weather system which had formed over the ocean halfway between New Zealand and Antarctica.
"Basically shuttlefuls of Antarctic air have been forced onto New Zealand -- we had the warm front on Monday night and the cold front arrived last night, which caused the thunderstorm."
He said the worst winds and rain were moving over the North Island this evening.
"Summer's taken on a mood change really, it might be the beginning of the end."
He said nonetheless the Metservice was expecting a few more anticyclones bringing dry conditions in autumn.
- NZPA, NEWSTALK ZB
