11 Nov 2022 | 04:31 AM UTC
New Zealand: Adverse weather forecast over most of North Island through at least Nov. 12 /update 1
Heavy rainfall, strong winds forecast across most of North Island, New Zealand, through at least Nov. 12. Flooding and disruptions possible.
Event
Heavy rainfall and strong winds are forecast across most of North Island through at least Nov. 12. A low-pressure system just north of Cape Reinga is forecast to move slowly southwestwards Nov. 11 with its associated fronts moving southwards, bringing further heavy rain and east to southeasterly gales to parts of the North Island. As of Nov. 11, the New Zealand National Meteorological Service (MetService) has issued the following weather warnings:
Orange (middle level on a three-tier scale) Heavy Rain Warning: Bay of Plenty including Rotorua, Coromandel Peninsula, and Gisborne. Heavy rainfall of up to 17 cm (7 inches) is likely.
Yellow Heavy Rain Watch: the ranges of Hawke's Bay, including the eastern hills south of Hastings.
Yellow Strong Wind Watch: Auckland including Great Barrier Island, Bay of Plenty east of Whakatane, Coromandel Peninsula, Horowhenua, Manawatu, and Taupo east of the lake.
Yellow Severe Thunderstorm Watch: Auckland and Northland.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Reports indicate that most of Coromandel Town in the Thames-Coromandel District is without power due to downed power lines from strong winds; authorities estimate regular power supply would resume the afternoon of Nov. 11. Portions of the SH1 between Kitchen and Makene roads through the Mangamuka Gorge, between Hukerenui and Jordan Valley roads in Whakapara, between Prospect Avenue and SH5 in Tirau, and between Waiouru and Rangipo are closed due to landslides, flooding, and damage. SH 25 from Hikuai to Tairua is also closed due to flooding.
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 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. Power outages could occur throughout the affected area.
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 delays and cancellations at regional airports. Authorities may temporarily suspend port operations 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 with 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.
