NZ North Island braces for ‘potentially devastating’ weather as cyclone Gabrielle barrels toward region

Communities across New Zealand’s North Island – some still recovering from flooding from record rain just weeks ago – are bracing for a “potentially devastating” weather event as ex-tropical cyclone Gabrielle barrels towards the region.

New Zealand’s MetService issued a series of red weather warnings Sunday for intense rain and gale force winds, including for Auckland which suffered record rains only two weeks ago.

The city’s 1.7 million residents were asked to be vigilant and prepare for the worst. The city could see up to 200mm of rain on Monday, with the Coromandel area to the east in line for 400mm, the MetService said.

“We are looking down the barrel of a very severe and potentially devastating weather event,” said Rachel Kelleher, deputy controller of Auckland Emergency Management.

The worst of the rain and winds for the city were expected on Monday, but a storm surge could coincide with a high tide in the early hours of Tuesday morning, the MetService said.

The western tip of the North Island had already seen wind gusts up to 140 km/h on Sunday morning, the weather agency said, warning Gabrielle was bringing a “very high risk of extreme, impactful and unprecedented weather” over many parts of the North Island from Sunday until Tuesday.

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“This is not a system to ignore, the worst is yet to come,” the agency said on Twitter on Sunday.

In a briefing on Sunday, the city’s mayor Wayne Brown said: “Cyclone Gabrielle is on our doorstep and it will be a challenging time for all of us, but we are well prepared and are taking it seriously. Aucklanders are strong and resilient and we will get through this.”

Kelleher said the severe winds and rain would come on top of already sodden land, risking structural problems, landslips, falling trees and powerline problems. The whole Auckland region was at risk of flooding, Kelleher said.

Some 370 households were still in emergency accommodation as a result of last month’s flooding, Kelleher said.

There was high demand for sandbags in the region, and the public were asked to prepare emergency packs and remove any blockages around drains and gutters to lessen the risk of floods.

The low pressure generated by the system could cause storm surges not seen for 40 years.

The MetService said gale force winds could extend 400km from Gabrielle’s centre. The storm was expected to intensify on Monday “as the low centre curves southwards, towards the Great Barrier Island and Coromandel Peninsula,” the agency said.

On Saturday night, the cyclone passed over Norfolk Island, an Australian territory, downing trees, blocking roads and causing power outages.

Dr Kevin Trenberth, an Auckland-based climate scientist, said hundreds of homes were still damaged from the “extraordinary” downpours at the end of January.

“This isn’t just these two events. We’ve had a raft of sub-tropical low pressure systems that have bombarded New Zealand this year.”

Trenberth, a distinguished scholar at the US-based National Center for Atmospheric Research and an honorary academic at the University of Auckland, said ocean temperatures around New Zealand were very warm and this provided fuel for storms and adds moisture for rainfall.

“But there’s a clearly a global warming signature to this,” he said, pointing to the long-term warming of oceans.