Weather warnings questioned after overnight Auckland downpours
by Karoline Tuckey, Soumya Bhamidipati · RNZAucklanders say severe weather alerts were too little too late, during a wild thunder and lightning storm that lashed Auckland and caused flooding on Easter Friday night, drawing comparisons with the devastating Auckland Anniversary weekend floods of 2023.
But Auckland Emergency Management is also making no apologies for sending out two alerts within several minutes of each other on Saturday afternoon.
An Auckland City councillor and a raft of voices on social media responded with frustration after official warnings of the intense and severe storm arrived after the storm did.
However, Auckland Emergency Management (AEM) general manager Adam Maggs defended the agency's response. He said AEM staff began speaking with MetService about midnight on Easter Friday, and a severe thunderstorm watch was issued shortly after.
MetService issued a yellow Thunderstorm Watch alert just after midnight, as heavy rain flooded parts of the city. While MetService meteorologist Alec Holden said thunderstorm development was difficult to forecast, a chain of various warnings had been issued for Ex-Tropical Cyclone Tam in the previous days, and their team's response to the observed conditions during the night of Easter Friday matched the criteria for the alerts issued.
But between 11:30pm Friday and 4am Saturday, Fire and Emergency said they received hundreds of calls for help in Auckland due to the storm. During that window, 223 weather-related calls were made asking for firefighters' help. Of those, two were water rescues where people were trapped in their cars by floodwaters - one in Wesley and one in Onehunga.
Streets and garages also flooded, AEM said firefighters were kept busy pulling cars out of floodwaters, and Fire and Emergency confirmed at least one home was set alight by lightning.
"Residents of Auckland's Sandringham and Mt Roskill fared the worst, with more than 100mm of rain recorded during the thunderstorm," Maggs said.
There were about 750 lightning strikes over Auckland, MetService said. Some streets became impassable or were closed, and Auckland Airport's updates board showed orange with rows of cancelled or delayed flights.
Two warnings in minutes
On Saturday afternoon, Auckland Emergency Management sent out two alerts within several minutes of each other.
Aucklanders phones blared at 2pm, alerting them to a severe thunderstorm warning that was due to expire at 2:15pm.
A second alert was sent shortly after that the warning had been extended until 3pm.
Maggs said they only had a few minutes' notice that the thunderstorm risk had increased.
"We made the call to get an EMA out to all Aucklanders to say be prepared to take action because we've got another thunderstorm cell coming through.
"We had a little bit of notice, a few minutes really, but we wanted to let our community know that was the risk.
"MetService subsequently changed the duration of the warning and extended it so we sent an additional EMA so at least the public are seeing accurate information about when the risk period is."
He said the region could expect more wild weather this afternoon with Central and West Auckland being the most affected.
Warnings must come sooner, Aucklanders say
But despite the two warnings on Saturday afternoon, Auckland City Councillor Shane Henderson said last night's warnings should have been up earlier.
"Last night we've had a situation where we've had at least an hour of huge downfall - people freaking out and having no information on how long this could last. I do think a warning should have been put in place a bit earlier than midnight."
Henderson said Aucklanders need to be given confidence they will be warned of storms in advance.
The storm and flooding brought back unwelcome memories from Cyclone Gabrielle, Auckland City Councillor Richard Hills said in a post on Bluesky.
"We are very lucky it stopped when it did. Very triggering for those affected in 2023."
Parts of Auckland received more than a month's worth of rain in just over an hour overnight, Hills said. Some areas had nearly beat 2022 records, while some had more than the highest amount of rain that had fallen in any one hour during the 2023 floods.
"A very intense night for many, especially if, like us, you live under one of those red dots," he said, referring to red dots on a map marking rainfall data.
"100mm of rain fell in the red parts, including large parts of the Shore and Central suburbs. Sadly some homes and streets were flooded again.
"Thinking of those affected. Hope you, your whānau and your property are doing okay. Please check on neighbours, people living alone and older residents you know."
Hills said all of the red dots showed places where more than 100mm of rain had fallen during the storm overnight, between Easter Friday and Saturday.
Social media users began posting dramatic footage online before midnight Friday, and Waimauku resident Brya Wallace said the first wave of Friday night's storm rolled over her home at the northern end of the Auckland region, about 10pm.
"There were a couple of thunderous booms that shook the whole house. There was one ... that sounded almost alien as it reverberated through the air before descending into a satisfying clap that shook the house," Wallace said.
A chain of angry comments followed AEM's first comment of the night to their Facebook emergency updates page at 12.42am Saturday.
"Warning issued at 00.43[am] for a massive thunderstorm that started almost an hour ago?!?", one said.
"A bit late, its been hammering down up that way for the last 2-3hrs," another said, while another posted: "That was one of the worst thunderstorms I've ever experienced in my 40+ years living in Auckland."
"A bit late, Blackbridge Road, Dairy Flat was sooo close to being flooded again. Thankfully rain has stopped so hopefully our flooding risk will ease. Felt like Auckland Anniversary weekend all over again," a Rodney vet nurse said.
Still another complained the warning was an "ambulance at the bottom of the cliff".
Auckland Mayor Wayne Brown released his first public statement on the storm, on X, just before 1pm on Saturday afternoon, saying it had been "an uncomfortable night for some Aucklanders".
"My thanks to the Auckland Emergency Management team who have been keeping me updated on the response. I also spoke to Minister Simon Watts earlier today.
"The team followed all the emergency protocols and mobilised quickly to respond to what was an unpredictable set of circumstances with an intense thunderstorm band that quickly developed into a sustained period of heavy rain."
The weather and civil defence agencies respond
"I think the key thing for us is that we were working with Fire and Emergency New Zealand right from the start of this, when the calls started coming in - and MetService - to understand the nature of where the system was tracking," AEM's Adam Maggs said.
"Initially, there wasn't an indication that (FENZ) were under any pressure or that the impacts were going to be that great. However, we started getting, you know, signals that actually there was some flooding happening."
At that point, AEM decided to set up its emergency co-ordination centre (ECC), Maggs said: "We were already liaising and working with FENZ, but by standing up at our ECC it means that we can get our staff together so that we can co-ordinate things, for example, such as the CDC (Civil Defence Centre) and setting that up.
"We feel like we responded effectively based on what we were facing with the pretty rapid-onset event."
Back up in North Auckland's Waimauku, Brya Wallace said the first storm to reach her had lasted for at least an hour, maybe even an hour and a half.
"I was actually playing a video game on my computer and could hear the thunder through my headset," she said. "My family and I were watching it for about an hour as it went from about 16km away, by counting the seconds, to overhead and passed overhead."
Weather events can happen very fast - AEM
The storm conditions had unfolded very quickly, Maggs told Saturday Morning: "These types of events can happen very quickly and without warning."
"What we noticed last night was we had a range of thunderstorm cells that trained - which means that they followed each other in a line across Auckland, around midnight, for about three hours into the early hours of the morning.
"That was what caused the impact, not only the light show, but also a lot of rain, particularly around Mt Roskill and Sandringham, within Auckland."
MetService uses a progressive colour-coded alert system of public notifications to warn about forecasts of severe weather, including heavy rain, strong wind and thunderstorms. Their red Warnings are rare and the most severe, orange Warnings are more common but also severe, while yellow Watches are used more often.
MetService meteorologist Alec Holden said: "There have been various watches and warnings for ex tropical cyclone Tam in place since early last week, where the risk of potential for thunderstorms and strong winds were noted as being possible."
"On Friday morning [18 April] there was a low risk of severe thunderstorms issued on the thunderstorm outlook chart covering the Auckland region. This reflected that at the time there was a potential for localised intense downpours overnight Friday/early Saturday morning."
MetService then "stood up" a night shift to monitor rain radar readings through the night, and at midnight: "In response to the increased thunderstorm activity we were seeing and the ongoing uncertainty, a Severe Thunderstorm Watch was issued ...to cover the risk of further intense downpours," he said.
"At the time what we were seeing did not meet the threshold for issuing a targeted Severe Thunderstorm Warning. Throughout the night, the on-duty forecaster was in direct contact with local agencies, providing real-time advice and updates as thunderstorms moved through the region."
However he noted that MetService alerts include their criteria, with Thunderstorm Watches specifying that prediction of thunderstorm activity is "highly uncertain," Holden said, including their development and location.
"With regards to if the Severe Thunderstorm Watch was adequate, we are always looking at ways to better our watch and warning processes.
"Following any significant weather event, we take the time to work through what happened, and tweak our criteria and thresholds. Each weather system is different, and part of what we do at MetService is learn from real life observations and the impacts on the ground."
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