18 Apr 2017

MetService defends 'dire' warnings ahead of Cyclone Cook

From Morning Report, 8:23 am on 18 April 2017

A Metservice meteorologist says, due to climate change, extreme weather events are likely to continue.

The stopbank wall which has been pushed onto College Road, was supposed to prevent flooding from the river Rangataiki but it breached and flooded the majority of the town causing the evacuation of 1600 residents.  Thursday 6 April 2017

The stopbank wall which has been pushed onto College Road, was supposed to prevent flooding from the river Rangataiki but it breached and flooded the majority of the town causing the evacuation of 1600 residents. Thursday 6 April 2017 Photo: RNZ/ Brad White

"We seem to be talking about records all the time. We're seeing the warmest temperature on record, the coldest temperature on record, the strongest wind gust on record for all the different regions around the country," MetService meteorologist Lisa Murray says.

Much of the country was braced last Thursday for Cyclone Cook which was predicted to be the worst weather event in decades.

This MetService infrared satellite from 6am shows the cyclone has largely passed the North Island and is moving over the South.

This MetService infrared satellite from 6am shows the cyclone has largely passed the North Island and is moving over the South. Photo: MetService

But in many areas, including Auckland where commuters left work early, the dangerous storm didn't pack the punch expected.

Media and forecasters have been criticised for getting it wrong and over-hyping the event.

But Lisa Murray is defending the warnings and says the result could have been very different.

"We have some very strict criteria that we adhere to for warnings. We only put a warning out if we are expecting gusts of 120kmh or 100ml of rainfall in 24 hours."

whakatane flood

whakatane flood Photo: RNZ

She says Auckland and Wellington missed the worst of it because Cyclone Cook tracked further east than expected and the centre of the low wasn't as deep as first thought.

Lisa Murray says it is notoriously hard to pinpoint  tracks from the tropics.

"Even 50 km in one direction or another direction can really impact the forecast for a region and that's exactly what happened in Auckland."

She says a team of 65 MetService meteorologists analyse numerous global models for consistency.

"The models aren't used to these very extreme events. So it certainly helps to have that human touch that we can add to the forecast and try to get the message, when there is a severe weather event out to the public.

"We want to be able to warn the public so they can protect their properties, protect their animals and protect their loved ones as well."