03 Jan 2023 | 02:03 AM UTC
New Zealand: Adverse weather forecast over most of North Island and far northwestern South Island through at least Jan. 5
Heavy rainfall, strong winds forecast across northern and central New Zealand, through Jan. 5. Flooding and disruptions possible.
Event
Heavy rainfall and strong winds are forecast across most of North Island and far northwestern South Island through at least Jan. 5. A subtropical low over the Tasman Sea is likely to bring heavy rain and possible severe gale northeasterlies to parts of the upper North Island and the Tasman District. Large northeast swells could bring hazardous conditions to exposed coasts. The heavy rain could cause landslides, surface flooding, and damage to roads. Severe gales could make driving conditions hazardous, especially for motorcycles and high-sided vehicles. Temporary structures such as tents could be affected. Authorities have advised residents to keep up to date with the latest forecasts in case any changes are made or further areas are added.
As of Jan. 3, the New Zealand National Meteorological Service (MetService) has issued the following weather warnings:
Orange (middle level on a three-tier scale) Heavy Rain Warning: Northland. 11-16 cm (4-6 inches) of rainfall is forecast mainly in the north and east, though 20-25 cm (8-10 inches) of rain is possible in the eastern hills.
Yellow Heavy Rain Watch: Auckland, Great Barrier Island, Bay Of Plenty west of Matata, Coromandel Peninsula, and Tasman west of Motueka.
Yellow Strong Wind Watch: Auckland, Great Barrier Island, Bay Of Plenty about and west of Tauranga, Coromandel Peninsula, Taihape, Taranaki, Taumarunui, Taupo, Waikato, and Waitomo.
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 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.
