Rotorua Daily Post
  • Rotorua Daily Post home
  • Latest news
  • Business
  • Opinion
  • Lifestyle
  • Property
  • Sport
  • Video
  • Death notices
  • Classifieds

Subscriptions

  • Herald Premium
  • Viva Premium
  • The Listener
  • BusinessDesk

Sections

  • Latest news
  • On The Up
  • Business
  • Opinion
  • Lifestyle
    • All Lifestyle
    • Residential property listings
  • Property
    • All Property
    • Dairy farming
    • Sheep & beef farming
    • Horticulture
    • Animal health
    • Rural business
    • Rural life
    • Rural technology
  • Rural
  • Sport

Locations

  • Tauranga
  • Te Puke
  • Whakatāne
  • Rotorua
  • Tokoroa
  • Taupō & Tūrangi

Media

  • Video
  • Photo galleries
  • Today's Paper - E-Editions
  • Photo sales

Weather

  • Rotorua
  • Tauranga
  • Whakatāne
  • Tokoroa
  • Taupō

NZME Network

  • Advertise with NZME
  • OneRoof
  • Driven Car Guide
  • BusinessDesk
  • Newstalk ZB
  • Sunlive
  • ZM
  • The Hits
  • Coast
  • Radio Hauraki
  • The Alternative Commentary Collective
  • Gold
  • Flava
  • iHeart Radio
  • Hokonui
  • Radio Wanaka
  • iHeartCountry New Zealand
  • Restaurant Hub
  • NZME Events

SubscribeSign In
Advertisement
Advertise with NZME.
Home / Rotorua Daily Post

Did Cyclone Cook really make a monster 12m wave?

Jamie Morton
By Jamie Morton
Multimedia Journalist·NZ Herald·
14 Apr, 2017 02:13 AM3 mins to read

Subscribe to listen

Access to Herald Premium articles require a Premium subscription. Subscribe now to listen.
Already a subscriber?  Sign in here

Listening to articles is free for open-access content—explore other articles or learn more about text-to-speech.
‌
Save

    Share this article

Waves crash on to Mount Maunganui beach as Cyclone Cook moves in last night. Photo / John Borren

Waves crash on to Mount Maunganui beach as Cyclone Cook moves in last night. Photo / John Borren

Did a wave the height of a four-storey building really form off the Bay of Plenty?

A 12m-high reading that was picked up by a wave buoy amid the thick of Cyclone Cook was one of the more dramatic figures that have emerged from the storm.

The regional council-operated buoy, located 13km off Pukehina Beach at a spot where the water is 62m deep, lies in a central position within the curve of the Bay of Plenty.

A graph shows maximum wave height climb sharply from around 5.5m yesterday afternoon to nearly 12.5m at 6pm, just when the cyclone was beginning to make landfall between Tauranga and Whakatane.

The "maximum wave height" simply measures the largest wave recorded, from peak to trough.

Advertisement
Advertise with NZME.
Advertisement
Advertise with NZME.

The instrument's "significant wave height" readings - the average measurement of the largest third of waves, something which corresponds well to our own visual estimates of wave height - dramatically climbed from 2.5m to 8m at 6pm.

At around 6pm, the average wave height was 5.1m.

But did one really reach over 12m?

Advertisement
Advertise with NZME.

"It's in the realms of possibility," said Niwa forecaster Chris Brandolino, who formerly served as a marine forecaster with Australia's Bureau of Meteorology.

"Could it have been bad data? I suppose ... but I'm inclined to believe that it was good data.

"So if we assume that it's good data, you can find waves can be above the height of the significant wave height.

"My understanding was that the buoy was continuously reading 8m, so if we take that as the general wave height, 12m falls within double - and these things can happen."

Discover more

New Zealand

Cyclone recovery begins in Whakatane

14 Apr 04:30 AM

For such a monster to have been created, Brandolino said a combination of three factors were needed: a high wind speed, a large area of water for winds to blow across, or what's called fetch, and a persistent wind direction.

"If the winds are coming from the north, continuously, the waves will build, but if it switches to the west, just by 30 degrees, a new wave will build: so you'd want minimal change in direction."

What would have it been like to confront a 12m wave?

"I would say it could have capsized a boat ... depending on the boat."

According to the World Meteorological Agency, it was also a buoy that last year recorded the highest wave ever: a 19m-high beast rolling in the North Atlantic Ocean between Iceland and the UK.

Save

    Share this article

Latest from Rotorua Daily Post

Rotorua Daily Post

Bay home crowd rallies behind netball's Magic

11 Jul 05:00 PM
Rotorua Daily Post

Tearful hunter admits shooting and killing friend

11 Jul 05:00 PM
Rotorua Daily Post

Mixed verdicts delivered for Tribesmen accused of murdering one of their own

11 Jul 05:00 AM

From early mornings to easy living

sponsored
Advertisement
Advertise with NZME.

Latest from Rotorua Daily Post

Bay home crowd rallies behind netball's Magic

Bay home crowd rallies behind netball's Magic

11 Jul 05:00 PM

The Magic play the Pulse in the ANZ Premiership at Baypark Arena on Saturday.

Tearful hunter admits shooting and killing friend

Tearful hunter admits shooting and killing friend

11 Jul 05:00 PM
Mixed verdicts delivered for Tribesmen accused of murdering one of their own

Mixed verdicts delivered for Tribesmen accused of murdering one of their own

11 Jul 05:00 AM
Pair deny charges over death of Paige Johnson in alleged hit-and-run

Pair deny charges over death of Paige Johnson in alleged hit-and-run

11 Jul 12:26 AM
Solar bat monitors uncover secrets of Auckland’s night sky
sponsored

Solar bat monitors uncover secrets of Auckland’s night sky

NZ Herald
  • About NZ Herald
  • Meet the journalists
  • Newsletters
  • Classifieds
  • Help & support
  • Contact us
  • House rules
  • Privacy Policy
  • Terms of use
  • Competition terms & conditions
  • Our use of AI
Subscriber Services
  • Rotorua Daily Post e-edition
  • Manage your print subscription
  • Manage your digital subscription
  • Subscribe to Herald Premium
  • Subscribe to the Rotorua Daily Post
  • Gift a subscription
  • Subscriber FAQs
  • Subscription terms & conditions
  • Promotions and subscriber benefits
NZME Network
  • Rotorua Daily Post
  • The New Zealand Herald
  • The Northland Age
  • The Northern Advocate
  • Waikato Herald
  • Bay of Plenty Times
  • Hawke's Bay Today
  • Whanganui Chronicle
  • Viva
  • NZ Listener
  • Newstalk ZB
  • BusinessDesk
  • OneRoof
  • Driven Car Guide
  • iHeart Radio
  • Restaurant Hub
NZME
  • About NZME
  • NZME careers
  • Advertise with NZME
  • Digital self-service advertising
  • Book your classified ad
  • Photo sales
  • NZME Events
  • © Copyright 2025 NZME Publishing Limited
TOP