Civil Defence is urging holidaymakers and residents in the Coromandel to find a safe and secure location while a storm passes through.
A subtropical low over the Tasman Sea is directing a strong and moist northeast flow over New Zealand, with some areas likely to receive warning amounts of rain and possible severe gale northeasterlies, MetService said. It warned large northeast swells could bring hazardous conditions to exposed coasts.
Earlier on Wednesday, the forecaster issued a heavy rain warning that will last from 9am until 11pm on Wednesday for the Northland region. There are more warnings for the Coromandel for 24 hours from 3pm on Wednesday, Bay of Plenty west of Matata from 9pm on Wednesday to 3am on Friday, and Tasman northwest of Motueka from midnight on Wednesday to 6am on Friday.
There is also a strong wind warning for Auckland, including Great Barrier Island, from 9am on Wednesday to 3am on Thursday.
In an update on Wednesday, the Thames-Coromandel District Council said residents and holidaymakers should "err on the side of caution". People in the area are urged to make plans and act before heavy rain and increasing gale-force north-easterly winds arrive. There is also a strong wind watch in place for the area for 24 hours from 6pm on Wednesday.
"While there is still some uncertainty, five more days of north-easterly wind and rain on the Coromandel is likely to have a wide impact. So, we urge you to consider going to a safe, secure location, or even heading home today until the storm passes," said Civil Defence Controller Garry Towler.
"The accumulation of rain by Saturday could see surface flooding, slips, road closures and power issues, so it is worth hatching a plan today to ensure no one is stuck or isolated."
There are further strong wind watches for the following: Northland from 9am on Wednesday to 1am on Thursday; Waikato, western Bay of Plenty to Taranaki, and Taihape for 24 hours from 6pm; and Banks Peninsula from 4pm to 10pm on Wednesday.
Additionally, there are heavy rain watches for: the ranges of Westland south of Otira for 24 hours from 5am on Thursday; Auckland, including Great Barrier Island, from 9am on Wednesday to 3am on Thursday; Mount Taranaki from 9am on Wednesday to 3am on Friday; and the Richmond and Bryant ranges, including the Rai Valley, and the Marlborough Sounds from 6am on Thursday to 3am on Friday.
MetService said earlier that rain had already set in over the upper North Island, with Kerikeri recording 74.4mm of rain as of 1:50pm. Also, 100km/h winds were recorded in Auckland and Northland.
