Auckland, NZ flooding, January 2023

  • Thread starter Thread starter Astronuc
  • Start date Start date
Click For Summary

Discussion Overview

The discussion centers around the severe flooding in Auckland, New Zealand, caused by record rainfall on January 27, 2023, and the subsequent impact of Cyclone Gabrielle. Participants explore the meteorological phenomena contributing to these events, including La Niña and East Coast Lows, while also sharing updates on the situation and related occurrences such as earthquakes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Some participants describe the flooding as a "weather bomb," with extensive rainfall leading to significant flooding in Auckland, including the airport terminal.
  • NIWA reported January 27, 2023, as potentially the wettest day on record for several locations in Auckland, with rainfall amounts reaching over 260 mm in a single day.
  • There are references to similar flooding events in Australia, suggesting a pattern influenced by climate phenomena like La Niña and the Indian Ocean Dipole.
  • Some participants note that La Niña may exacerbate typical weather patterns such as East Coast Lows, which are intense low-pressure systems affecting the eastern coast of Australia.
  • Updates on the situation include reports of fatalities and ongoing weather warnings, indicating the severity of the flooding and its aftermath.
  • Participants mention the declaration of a national emergency in New Zealand due to Cyclone Gabrielle, highlighting the significant impact of heavy rains and winds across the North Island.
  • There are mentions of an earthquake occurring concurrently with the weather events, although participants note no reported damage from the quake itself.

Areas of Agreement / Disagreement

Participants express a range of viewpoints regarding the causes and implications of the flooding and cyclone, with no consensus on the overall impact or the effectiveness of responses. The discussion remains unresolved regarding the interplay of the various meteorological factors at play.

Contextual Notes

The discussion reflects ongoing uncertainty about the long-term implications of these weather events and their connections to broader climate patterns. Specific assumptions regarding the influence of La Niña and East Coast Lows remain unverified within the conversation.

Who May Find This Useful

Readers interested in meteorology, climate science, and the impacts of extreme weather events may find this discussion relevant.

Astronuc
Staff Emeritus
Science Advisor
Gold Member
2025 Award
Messages
22,512
Reaction score
7,443
In what one emergency service person described as a bit of a weather bomb, the Auckland city and region is seeing extensive flooding. The main terminal at Auckland airport is flooded.

https://www.nzherald.co.nz/nz/auckl...nz-nzdf-called-in/3YQ54VEQTJE2HJDRYHLYAYHOTQ/

https://www.nzherald.co.nz/nz/auckl...oating-down-roads/GGO5X6624FDWLPRM7EDHGC4QEY/

It seems to be a highly unusual weather event described as "record rain caused widespread flooding on 27 January 2023."

New Zealand’s National Institute of Water and Atmospheric Research (NIWA) said that 27 January 2023 is “provisionally, the wettest day on record for multiple locations in Auckland.”

In a period from 03:00 to 21:00, the Auckland Albany weather station recorded 260.6 mm of rain; Auckland Motat 238.4 mm; and Auckland Māngere 242.0 mm.

NIWA said “this is approximately an entire summer’s worth of rain (DJF) in one day! Even when using the conventional 9:00 am start time when calculating daily rainfall produces new daily records.
https://floodlist.com/australia/new-zealand-floods-auckland-record-rain-january-2023

Reminds me of the flooding in Victoria and New South Wales during the last two years.

https://floodlist.com/australia/floods-nsw-victoria-november-2022
https://floodlist.com/australia/floods-victoria-tasmania-newsouthwales-october-2022
https://www.smh.com.au/interactive/2022/lismore-flooding/

An explanation:
Australia is exposed, for a third straight year, to the La Niña weather phenomenon in the Pacific Ocean, which typically brings above-average rainfall to the country's east.

Another contributor is the Indian Ocean Dipole - a climate phenomenon that affects rainfall patterns near the Indian Ocean, including Australia. It turned negative in May, increasing the chances of above-average rainfall for most of Australia in the September-November spring.

"The oceans north of Australia are warmer and that causes more moisture flowing from the Indian ocean to eastern parts of Australia," said Agus Santoso, senior researcher at the University of New South Wales Climate Research Centre.
https://www.reuters.com/world/asia-...country-is-battling-weather-again-2022-10-15/

Apparently, the La Niña weather phenomenon exacerbates a typical weather pattern known as an East Coast Low
East Coast Lows (ECL) are intense low pressure systems which occur, on average, several times each year off the eastern coast of Australia, in particular southern Queensland, NSW and eastern Victoria. Although they can occur at any time of the year, they are more common during autumn and winter with a maximum frequency in June. East Coast Lows will often intensify rapidly over a period of 12-24 hours making them one of the more dangerous weather systems to affect the eastern coast. East coast lows are also observed off the coast of Africa and America and are sometimes known as east coast cyclones.
http://www.bom.gov.au/weather-services/severe-weather-knowledge-centre/eastcoastlows.shtml
 
Earth sciences news on Phys.org
 
New Zealand declares national emergency in wake of historic Cyclone Gabrielle
https://www.foxweather.com/weather-news/new-zealand-declares-national-emergency-cyclone-gabrielle

AUCKLAND, New Zealand – Cyclone Gabrielle continued to batter New Zealand on Tuesday, leaving widespread flooding and wind damage and prompting the prime minister to declare a national state of emergency.

"That means we’ll be throwing everything at this to make sure that we provide as much support to the response as possible," Prime Minister Chris Hipkins said in a news conference Tuesday as the country worked to clean up from the powerful tropical system. It was just the third national emergency declared in the nation's history.

Heavy rains of 6-12 inches (15.2-30.5 cm) fell across the North Island as winds gusted to 55-80 mph (88.5-129 kmph) along the mainlands and 80-100 mph (129-161 kmph) on some of their more exposed islands. Channel Island recorded a gust of 101 mph (163 kmph), according to New Zealand's MetService.
 
https://www.stuff.co.nz/dominion-po...-heavy-rain-after-63-quake-on-wednesday-night

The house rattled for a while then increasing started to shake - for a significant period of time. As that was occurring I got an Android alert to expect 'light shaking'.From https://www.stuff.co.nz/national/300808301/lower-north-island-rocked-by-magnitude-63-earthquake
"When asked how he felt about the quake Prime Minister Chris Hipkins said it was “unprintable”.
“I was looking out the window for a plague of locusts.”"
 
  • Like
Likes   Reactions: BillTre
Earthquake + heavy cyclone!
 
Astronuc said:
Earthquake + heavy cyclone!
Yup. As far as I'm aware, there is no reported damage from the earthquake. Just Cyclone Gabrielle, especially in the upper North Island and Hawke's Bay.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 1 ·
Replies
1
Views
4K