09 May 2023 | 02:48 AM UTC
New Zealand: Adverse weather forecast over much of North Island and northern South Island through at least May 11 /update 2
Severe weather forecast over parts of northern and central New Zealand through May 11. Flooding, transport disruptions ongoing.
Event
Severe weather is forecast over northern and western North Island and northern South Island through at least May 11. As of May 9, the Meteorological Service of New Zealand (MetService) has issued the following watches and warnings:
Red Severe Thunderstorm Warning (the highest level on a three-tier scale): Albany, Auckland City, Franklin, Gulf, Hauraki, Rodney, and Waikato.
Yellow Severe Thunderstorm Warning: Auckland, Bay of Plenty, Coromandel Peninsula, Great Barrier Island, Northland, Rotorua, and Waikato.
Orange Heavy Rain Warning (the middle level on a three-tier scale): Auckland including Great Barrier Island and Coromandel Peninsula, Bay of Plenty including Rotorua, Mount Taranaki, Tasman from Motueka westwards, Marlborough about and north of the Awatere Valley, Nelson, Tasman south and east of Motueka, Grey and Westland Districts from Fox Glacier town northwards, and Headwaters of the Canterbury Lakes and Rivers from Arthur's Pass to Lake Tekapo. The heaviest rainfall of up to 15 cm is forecast over Grey and Westland districts.
Yellow Heavy Rain Watch: Buller and North Taranaki away from the Mountain.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Officials have imposed a State of Emergency in Auckland as a result of the widespread floods affecting northern and western parts of Northland. The Northern Motorway is closed between Northcote and Esdmonde roads due to poor driving conditions, while State Highway 1 at Dome Valley and Brynderwyn Hills is closed due to flooding. Reports indicate that evacuations are ongoing at several schools across Auckland. Heavy rain and thunderstorms in the Auckland Region are likely to continue through at least midnight May 9.
Hazardous Conditions
Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Additional power outages are possible in areas impacted by the weather system.
Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. The disruptive weather may cause additional delays and cancellations at airports across the affected region. Flooding could block regional rail lines; freight cancellations are possible in areas subject to heavy rainfall and track blockages.
Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after weather conditions have improved; it could take days before any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.
Advice
Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast or reported. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.
