Niwa forecaster Seth Carrier said the storm came with several notable and unusual features. "This is sort of like a West Coast rain event, but in reverse," Carrier said of the impact on the South Island's east coast.
And while specific conditions explain the storm, it is also known that intense, impactful weather events are becoming more frequent with climate change.
Every year now features dramatic fires, cyclones, droughts and storms on a scale that surprise people. Even as debates occur on how to reduce carbon emissions, different regions of the world are being regularly hit by hugely costly weather disasters.
The cost to insurers of storms, fires, tornadoes and floods last year was $273.8 million and $205.9m in 2019 and $226.3m in 2018, according to Insurance Council of New Zealand figures. That compares with $76.2m (inflation adjusted) in 2010, $6.8m in 2009, $99.1m in 2008 and $150.7m in 2007.
The increasing cost and intensity of disasters is reflected in other countries. NOAA figures for United States disasters costing at least US$1 billion show that for the last five years there were 16.2 per year costing US$123.3b per year. In the 1990s (inflation adjusted) that was 5.3 per year and US$27.7b per year.
Coastal New South Wales in Australia is still recovering from record rainfall in March which caused A$600m worth of damage. ABC reports that scientific data shows lower rainfall has meant a huge fall in water flowing across Australia's largest river system, the Murray-Darling Basin, in the past 20 years.
In Western Australia in April, the town of Northampton was hit by tropical cyclone Seroja. The last such event was tropical cyclone Hazel which made landfall in the state in 1979.
Simon Bradshaw, a researcher for Australia's Climate Council, told SBS: "It tracked very far south, it was unusually intense for that time of year, and it retained that strength for longer than was forecast as well.
"Now these are all things we've been told to expect from climate change and cyclones."
Public and legal pressure is increasing on governments and big companies to step up. Last week oil corporations were forced to take action to reduce emissions. Exxon Mobil lost a shareholder revolt seeking to shake up its board. Chevron investors told the company to cut its emissions. A court told Royal Dutch Shell to slash emissions by 45 per cent in nine years.
Yesterday, the Climate Change Commission delivered its final recommendations to the Government on New Zealand's plan of attack for the next 15 years, after going through 15,500 submissions on its draft report. The country's commitment is to be net-zero by 2050.
This is one chunk of future planning we can't squabble about and do nothing. The problem the world is grappling with will chase us the whole way.
