Many roads were closed and public transport was disrupted by flooding, downed trees and debris Auckland Transportationwhich urged people to avoid travel until Tuesday.
“This is an unprecedented weather event that is having a major impact on much of the North Island,” said Kieran McAnulty, the country’s minister for emergency management.
Two houses collapsed with people trapped in the coastal community of Muriwai, west of Auckland, the New Zealand Herald reported. Fire and Emergency New Zealand said further his Twitter account that its communications center received more than 500 storm-related calls in 15 hours.
Early Tuesday, the country’s MetService said the heaviest rainfall totals over the past 24 hours included up to 400 millimeters (15.7 inches) in Gisborne and up to 260 mm (10.2 inches) in Hawke’s Bay, with Coromandel measuring 300 mm (11.8 inches) received ) within 26 hours. A record storm surge of at least 0.7 meters (2.3 ft) was reported at Whitianga monitoring station in the Waikato region south of Auckland. In the capital, Wellington, some schools closed as a precaution on Tuesday as the storm surge swept south across the country.
Wind gusts had exceeded 140 kilometers per hour (87 miles per hour) in the Northland region as the storm’s low pressure center moved near the north coast of the North Island.
Before hitting the North Island, the storm had progressed from a tropical cyclone — equivalent in strength to a high-end Category 1 hurricane — to a still-strong subtropical storm.
Before the storm, the MetService had warned that Gabrielle was “at VERY HIGH risk of extreme, disruptive and unprecedented weather in many regions of the North Island.”
Forecasters expected rain to ease in northern parts of the North Island on Tuesday, even if strong winds persist, with heavy rain and strong winds persisting in eastern areas, including around Gisborne. Rain and wind impacts were forecast as far north as the South Island.
Most of the North Island should see significantly improved conditions through Wednesday as the storm moves east away from land.
This latest storm comes not long after several locations in Auckland recorded their wettest day on record on January 27; Four people died in the resulting flooding. New all-time daily rainfall records reported from the country’s National Institute of Water and Atmospheric Research included 260.6 millimeters (10.25 in) at Albany, 242 millimeters (9.5 in) at Mangere, and 238.4 millimeters (9.4 in) at Motat.
During this storm, Auckland Airport was closed due to flooding in the terminal. The observation station at the airport recorded 5 inches of rain in two hours.
A marine heatwave in the tropical southwest Pacific – caused by sea temperatures up to 6 degrees Celsius (11 degrees Fahrenheit) above normal – has helped fuel the torrential downpours.
Meteorologists say La Niña, the impact of climate change, ongoing urbanization and aging infrastructure have all contributed to the more severe flooding impacts in northern New Zealand. January was the wettest month in Auckland on record, with 539 millimeters (21.2 inches) of rain, beating the previous monthly record of 420 millimeters (16.5 inches) in February 1869.
Auckland’s record-breaking rains in January were intensified by the impact of climate change, said NIWA climate scientist Sam Dean. A New Zealand government report found that the impacts of climate change are likely to increase “very extreme rainfall events… with larger increases in shorter-duration events.”