Red warnings and red alerts for rain, winds or both are now in place for the entirety of the North Island. “This is a serious event for New Zealand,” said MetService’s Georgina Griffith at the Auckland Emergency Management briefing this afternoon. “Red warnings are not issued lightly.” Severe weather had already impacted Northland and Aotea Great Barrier Island but what had been experienced in Auckland so far was no more than an “entrée”, she said. “Don’t be fooled if you’re not affected till Tuesday, and just remember – today? Today is the good day.”
Forecasts point to 200mm-250mm rainfall in Auckland north of Whangaparāoa and Barrier, with 150mm and 220mm rain for other parts of Auckland.
Red warnings for heavy rain and strong wind have been issued Auckland and Aotea Great Barrier Island, with harsh rain and wind expected from Sunday night and the most severe impacts on Monday and Tuesday.
“High intensity deluge or downpour events” of 35mm to 40mm an hour are possible from Monday afternoon. This is expected to cause dangerous river conditions and significant flooding, with slips and floodwaters disrupting travel, leaving some roads impassable and potentially isolating some communities. “Plan for flooding or slip impacts and count yourself lucky if you don’t see them – other parts of Auckland almost certainly will,” said Griffith.
Severe gales, with gusts up to 130 km/h from Monday are expected to cause widespread damage, with risks to trees and powerlines, as well as a risk of roofs being lifted. Road closures and power outages are likely, with conditions rated hazardous for motorists and “a danger to life from flying debris and falling trees or branches”. The wind gusts are “top end” with a low that “we haven’t seen in 40 years”, said Griffith.
Storm surges are another risk, potentially measuring up to half a metre along eastern coastlines on Monday afternoon and into the high tide in the very early hours of Tuesday morning. Throw low pressure and strong onshore winds into the mix and “there is now a high risk of coastal inundation on the Monday evening high tide”.
AEM deputy controller Rachel Kelleher warned that while the rainfall might not be as great in most parts of Auckland as a fortnight ago, the risks, on top of that event especially, are very serious. “Wind first, then the heavy rain on Monday, then possibly that storm surge at 2am Tuesday – be vigilant … Plan, prepare, check in on family and friends and take the steps needed to be safe.”