Atmospheric river warnings for West Coast

Northland and Auckland have heavy rain and severe weather warnings in place. Nelson, Tasman, and Marlborough have also experienced heavy rain.

However MetService suggests that the worst of the heavy rain is already over, and that it should clear up over the weekend.

Meteorologist Mmathapelo Makgabutlane says by the end of Friday, most of the country should be clear of the severe weather.

Atmospheric rivers are narrow, long weather events that carry a lot of concentrated water vapor. They are often referred to as sky rivers.  

NIWA climate scientists say New Zealand could face twice as many of the most extreme atmospheric rivers by the end of the century, according to new research.

Scientists say atmospheric rivers can have twice the water flow of the Amazon River. Sky rivers can cause massive amounts of flooding and serious rain events.

Atmospheric rivers make up most of the biggest weather events in recent years, including the West Coast flooding that took out the Waiho Bridge in 2019, and the Westport flooding in 2021.

The most recent was in the summer of 2022/23 when Auckland was hit with flooding and constant downpours.  

Most atmospheric rivers are formed over warmer tropical climates such as Fiji or Tonga, but this one has been formed over the Tasman Sea, been carried to New Zealand on strong wind currents and low-level jet streams.

NIWA scientists had predicted sky rivers would make up almost half of Aotearoa’s annual rainfall by the end of the century, and that the number could double. However they had not realised they would become so prevalent this fast.

MetService recommends people still prepare for a wet and stormy weekend, follow any information that local council or civil defence provides, and make sure all pets are safe.