Satellite view of Cyclone Gabrielle

Cyclone Gabrielle causes national state of emergency in New Zealand

by Kirsty McCabe, FRMetS


New Zealand declared its third ever national state of emergency in February 2023, following the passage of Cyclone Gabrielle, with the government attributing the scale of the disaster to climate change.

For those living in Auckland, the country’s largest city, the extreme weather was particularly unwelcome as they were still recovering from their wettest day on record just a fortnight earlier. At least four people died following January’s torrential thundery downpours, which led to significant damage and flooding across Auckland and the North Island.



  • Auckland had its wettest day with 280mm at Albert Park (211mm of that fell in under 6 hours)
  • In less than an hour, a month's worth of rain fell at Auckland airport (equivalent to January's rainfall)
  • Unsurprisingly, January 2023 was the wettest month since records began, with 539mm of rain at Albert Park


The National Institute of Water and Atmospheric Research, the country's climate science body, said 27 January was the wettest day on record for a number of locations, describing it as a 1-in-200 year event.



The torrential rain prompted widespread flooding, evacuations and flight cancellations. Footage and images online showed people trapped in waist-deep floodwater, rescuers carrying out evacuations on kayaks, and grocery items floating down supermarket aisles.


An unusual combination of environmental factors led to Auckland’s wettest day in history; a formidable La Niña, a marine heatwave and a nearby subtropical depression led to more moisture being available. A trough in the jet stream and converging winds over the city led to an entire summer’s worth of rain falling on the city in less than a day.

As the residents of Auckland recovered, attention shifted to a new threat. Long-range forecasts indicated a tropical cyclone could bring severe weather mid February, so New Zealand's MetService provided early insights and important communications.



MetService Māori Communications


The far north of New Zealand has a subtropical climate and does occasionally catch the tail end of tropical systems. Currently, an average of about 10 tropical cyclones form in the South Pacific tropics between November and April each year, and about one of those will affect New Zealand as an ex-tropical cyclone (usually in February or March).


Cyclone Gabrielle track


But don’t be fooled by the reclassification of tropical to ex-tropical, as these storm systems can still bring severe weather. As was the case with Gabrielle. This tropical cyclone reached severe category 3 in the South Pacific, before transitioning into a deep subtropical low and heading to New Zealand.




Multiple heavy rain and wind warnings were issued across the North Island as Gabrielle approached. States of emergency that were already in place in Auckland and the Coromandel as a result of January's floods were extended.



Gabrielle affected the North Island and the top of the South Island from 12 to 16 February, with a national state of emergency declared on 14 February. About half of the country’s population was affected, with around 10,000 forced from their homes, and at least six people lost their lives.

Strong winds led to widespread power outages and property damage, while heavy rainfall caused severe flooding and landslides. The military helped with evacuations and delivered supplies to the worst-affected parts of the North Island.



While New Zealand has been affected by ex-tropical cyclones before, climate change is more than likely to blame for the intensity of Gabrielle, which brought more destruction to the country than any weather event in decades. And it doesn't bode well for the future, as a warming atmosphere will increase the intensity and frequency of extreme rainfall events.

A study published at the end of March 2023 by the World Weather Attribution found that the rainfall from Gabrielle was about 30% heavier, and that climate change undoubtedly played a role.

Categories: Climate In the Spotlight Weather
Tags: Climate Climate Change Extreme Weather News Precipitation Storms Tropical Cyclones Weather Wind WorldWeather

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