New Zealand / Weather

Weather models would still struggle to predict Auckland Anniversary floods - MetService

18:13 pm on 31 January 2024

The home of Kannan Thiru was surrounded by a large pool of water still on Wednesday afternoon. Photo: RNZ / Cole Eastham-Farrelly

MetService says it would still struggle to predict the intensity of last year's Auckland floods if they were to happen again.

It has been one year since a major deluge of wet weather battered parts of the North Island on Auckland Anniversary weekend.

Monday will mark a year since Cyclone Gabrielle also caused widespread damage to homes and properties, particularly in Hawkes Bay and Tai Rāwhiti.

MetService head of weather communications Lisa Murray said it had undertaken an independent review of its procedure, as was normal for any major weather event.

However, she prefaced by saying there was little that could have been done differently when forecasting the Auckland Anniversary Floods weather.

"That Auckland Anniversary flood was a really extreme event - an anomaly in terms of forecasting. All the weather models would still struggle to identify that in advance."

In comparison, she said it had forecast Cyclone Gabrielle well.

"We're actually quite proud of how we forecast Cyclone Gabrielle. We put out warnings earlier than we normally do, we put out communications about Cyclone Gabrielle over a week in advance.

"We actually communicated very well that Cyclone Gabrielle was coming down."

Photo: RNZ / Samuel Rillstone

Despite that, Murray said some changes were made to improve its communication and operations, including more streamlined engagement with regional councils, Civil Defence and the National Emergency Management Agency .

Murray said it had worked towards simpler messaging about weather watches and warning.

On Thursday, it had released a feature on its app which released push notifications to warn people in the paths of extreme storms or in areas with a high fire risk.

This feature was something she was proud to finally get across the line after a year of development and a partnership with Fire Emergency NZ, she said.

"I'm personally quite excited about these push notifications, because even if you don't want to use the MetService app, if you have that on your phone just to get those notifications, that could potentially be a life-saving and death situation."

While some models might not predict an Auckland flood again, she said meteorologists could apply prior experiences to change the MetService warning level.

The threshold for what constituted a rain watch and warning had not changed, because it was in the hands of regional experts to decide how much rain a region was capable of taking, she said.

Areas like Hawkes Bay and Auckland, for example, briefly lowered their threshold after Cyclone Gabrielle, but had since returned them to normal, she said.