26 Jul 2021 | 08:26 AM UTC
New Zealand: Heavy rainfall forecast in multiple locations through at least early July 27 /update 1
Heavy rainfall forecast in parts of northern and western New Zealand through at least early July 27. Disruptions possible.
Event
Heavy rainfall is forecast in portions of northern and western New Zealand through at least early July 27. The affected areas include Auckland, Bay of Plenty, Gisborne, Marlborough, Nelson, Taranaki, Waikato, and West Coast regions. As of July 26, the New Zealand National Meteorological Service (MetService) has issued the following warnings:
Orange Heavy Rain Warning (the middle level on a three-tier scale): Bay of Plenty, including Rotorua, Coromandel Peninsula, Nelson west of Motueka, and Westland south of Otira. Up to 11 cm (3 inches) of rainfall could occur in these areas.
Yellow Heavy Rain Watch (the lowest level on a three-tier scale): Buller, Gisborne, Mount Taranaki, Waikato, Marlborough, and the rest of Nelson.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
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 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. Power outages could occur throughout the affected area.
Transport
Strong winds have prompted officials to cancel some commuter ferry services in Auckland. All Pine Harbour Ferry and Gulf Harbour Ferry services were canceled and replaced by bus services early July 26; services for Pine Harbour Ferry have resumed 11:40 July 26. Additionally, 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 some delays and cancellations at regional airports. Authorities may temporarily suspend port operations along the Bay of Plenty, Tasman Sea, and Cook Strait if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding could block regional rail lines; freight cancellations are possible in areas that see heavy rainfall and potential track blockages.
Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after 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. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.