Tasman Tempest: Auckland's wettest March day in 58 years

Monday, 13 March 2017

A deluge caused major flooding in the West Auckland suburb of New Lynn on Sunday. Resident James Ellis' home was waterlogged.

The Tasman Tempest dumped more rain in some places in six days than is usually expected for the entire month of March, new figures reveal.

The storm, which battered Northland, Auckland and Waikato from Tuesday to Sunday, washed away weather records held in some places for decades, Niwa said.

It caused widespread flooding, property and livestock losses and power outages to more than 2.2 million residents.

Whangamata received the most total rain, with 475mm falling over the six days - more than the town would usually receive throughout all of autumn.

A footpath collapsed in New Lynn following the deluge, opening up a temporary sink hole.

* Live: Flooding strikes scores of Auckland homes as storm spreads across North Island

* Flash floods, landslides and power cuts strike Waiheke Island, causing widespread damage**

The spillway of the Lower Nihotupu Dam in west Auckland catches the dam's overflow from heavy rain over the weekend.

Kaitaia also had its wettest March hour since records began in 1962, with 44.6mm of rain falling between 3am and 4am on Saturday.

Auckland hit its wettest March hour since 1965 with 27mm of rain falling from 5pm to 6pm on Friday.

Charles Malcolm begins the long cleanup of silt from his flooded property in Clevedon, south Auckland.

That day was also the wettest for Auckland since 1959, with 100mm falling from 9am.

Hunua saw a 1 in 100-year rain event, and New Lynn's flash floods were the result of a 1 in 30-year rainfall, Niwa meteorologist Ben Noll said.

The intensity of the storm could have been fuelled by climate change, he said.

'While no one weather event is caused by climate change, all events are influenced by climate change since the atmosphere is now warmer and wetter than it was in the past.

'Climate change increases the likelihood of extreme rainfall, given the appropriate weather setup.'

Reearch suggested there would be up to eight per cent more intense rain for every one degree Celsius of warming, Noll said.

GOODBYE TEMPEST, HELLO SUNSHINE

High pressure building over New Zealand this week would cause much calmer conditions across the upper North Island, and the country as a whole, Noll said.

'The humidity that the Tempest brought will be replaced with typical crisp autumn mornings, though afternoons will be filled with sunshine and comfortable warmth for many.

'For those looking to have some late-season beach days, next weekend is looking pretty fabulous across the upper North Island.'

And for the rest of the month?

'Long stretches of dry weather and sunshine with temperatures near or above average.'