Not so swell messaging - a homeowner's view of the Wellington state of emergency
Friday, 12 June 2026
OPINION: The first heavy swell warning arrived in my inbox at 11.29am on Sunday, June 7.
I was out and about so didn’t see it until later. But when I did, I was nervous.
Having owned a house in Ōwhiro Bay since 2005, I’ve had two decades to learn to read the ever-changing sea.
The emailed swell warnings are a legacy of the April 2020 waves that thundered down on us on a windless, blue sky day with absolutely no warning. It emerged, then, that the weather boffins had had two days of watching them track up from Antarctica, but no-one thought to tell us.
Read more:
State of emergency lifted for Wellington coast as danger from big waves recedes
Wellington south coast residents told to leave homes ahead of huge Cook Strait swells
Explaining why he called a state of emergency this time around, Wellington Mayor Andrew Little said that, after the 2020 event, the community asked the authorities to be more proactive in the future.
Actually, what we asked for was good information, so we can make good decisions and be prepared.
The emailed swell warnings - which emerged out of a joint agency and community working group - have been a brilliant innovation.
Sure, the crystal ball is a little smudgy and sometimes the swells come to nothing. But I’d always rather be over-prepared, than caught completely unawares.
What nobody wants, though, is bad, holey or conflicting information.
When I’m scanning a swell warning, I’ve learnt to look for three key things - high tide time, swell height, and period - the time between waves. That matters because the longer the interval between waves, the greater the power behind them, so the more destructive they can be at any height.
Given the April 2020 thumpers had a peak period of about 15 seconds, any prediction in the double-digits is an orange flag and anything longer than about 13 seconds blinks red.
I’m also checking Niwa’s annual tide calendar, which is magneted to the fridge. That tells me whether it’s a king tide “red alert” day, when any waves are amplified by the already high tide, or a “carefree” low tide period.
All of which is to say, coast-dwellers are not wave scientists but neither are we ignorant of the factors that combine to create risk where we live.
Like surfers and fishers, who can tell you better than any generic forecaster exactly how different weather will affect their particular patch, when you’ve spent every day somewhere for 20 years, you have some idea of how different wave predictions land on your stretch of beach.
But all that relies on good, clear and consistent information. That initial Sunday warning, two days out from the event, predicted a swell of 6.5-7.5m, with a period of 15-17 seconds. By Monday morning, that had escalated to 7.5-8m swells.
By any measure, those are numbers to take notice of. So I checked MetService’s Ōwhiro Bay boating forecast, which is generally a more useful and detailed picture, as it gives swell, wind and chop predictions in 3-hour bites, so you can see how conditions change over the day.
Unfortunately that forecast just got less useful, as it no longer includes the period from 6pm to 6am. (MetService says its boating forecasts were changed in March 2025 to provide 3-hourly instead of 6-hourly updates, but only during daytime.)
It also never seemed to marry up with the information in the swell warning, with the boating forecast predicting swell height to peak more than two metres lower, at just 5.3m, with a 15-second period, around 3pm.
Even on those numbers, it might have been fair to declare a state of emergency and ask residents to be out by 9am on Tuesday. Having stared in disbelief at the muddy tide marks on flood-trashed Esk Valley homes, and listened to the traumatic retelling of those trapped inside who were never given the chance to evacuate, I’m sympathetic to the plight of mayors who know they’re damned if they do and damned if they don’t. No-one wants lost lives on their conscience.
And while I was watching from afar for this event, everyone in our bay appreciated the Monday evening door-knock by Wellington Regional Emergency Managament Office (in some cases by radio host Grant Kereama) to advise residents of the potential danger. Especially given several never received the phone emergency alert.
But it was the mixed messages that followed that got people’s backs up. At 8.35am on the Tuesday, a MetService Facebook post announced they’d “already seen significant wave heights of 6 metres overnight, and maximum wave heights just about cracking 10 metres…but the biggest waves are yet to come!”
Those numbers appeared to relate to waves at the Baring Head offshore buoy miles from the South Coast, which might be relevant if you’re a ferry captain wondering whether to sail, but only confuses people wanting to understand the wave risk on shore.
To complicate matters further, asked why the warning and boating forecast wave heights don’t marry up, MetService says it uses “deep water” heights for swell warnings. Long-period waves tend to break further out and lose height closer to shore, which explains the very different numbers.
MetService says agencies decided to use deep water heights for swell warnings back when the warnings were set up because they had a good understanding of the impacts from long-period swell of 6m and over.
All of which is muddy as heck if you’re trying to make sense of the risk. But by 1pm or so, more than an hour after the biggest danger point of the 11.19am high tide, it was clear to any veteran of coastal swells that this was not going to be a major deal.
A handful of waves had flopped over the road, carrying some sticky debris. But nothing hit like those 2020 swells, which took out garage doors and invited themselves into homes.
Yes, there was another high tide to come, after 11pm, but the swells were always forecast to drop, so it made sense that if the morning high tide had come to little, the evening one was likely to present even less threat.
MetService had also reportedly told a briefing on the Tuesday morning that the wave heights were likely to be lower than initially forecast. That info was not passed on to residents.
Little’s 2pm announcement that the evacuation would be extended overnight, therefore seemed inexplicable and overkill. So, many residents simply made their own decisions, and walked straight through the cordon to go home.
At 4.16pm, an updated swell warning landed in my inbox, significantly downgrading the predicted evening waves. But it wasn’t until after 5pm that the state of emergency was lifted and the evacuation order rescinded, allowing residents back into their homes.
By then, several people had shelled out hundreds of dollars for Airbnbs for the night, and were understandably pissed off. One called it “outrageous“. And the problem with pissed-off people is that if they think the decision-making process is flawed, next time they might not move when asked.
Everyone understands that the sea is a fickle thing. A rogue set can do unexpected damage; a slight change in wave direction can completely alter its impact. Just give us the best information you have, so we can make informed decisions. And that means detailed, consistent predictions, broken down in chunks through the day, and through the night. So we can see what’s forecast, and how that compares to what’s happening on the beach.
As one Ōwhiro Bay resident says: “They might have made the right call with the information they had, but they should share it.”