New Zealand: Adverse weather forecast for northeastern parts of North Island through at least Jan. 19

Event

Severe weather is forecast across northeastern parts of North Island through at least Jan. 19. A low-pressure system is forecast to pass close to East Cape late Jan. 18-early Jan. 19, bringing heavy rainfall to much of Gisborne Region and strong winds to northern parts of Gisborne and eastern parts of Bay of Plenty regions. Rainfall totals of 7-9 cm (2.8-3.5 inches) are forecast across northern and central parts of the Gisborne Region. Heavy downpours could cause landslides, flooding, and damage to roads, especially in areas where the ground is already saturated by previous rainfall following the passing of ex-tropical cyclone Hale over parts of North Island Jan. 9-11. A state of emergency remains in place over the Gisborne Region due to severe flooding caused by the storm.

As of late Jan. 17, the New Zealand MetService has issued the following weather warnings across the affected areas:

• Orange (middle level on a three-tier scale) Heavy Rain Warning: Gisborne north of Tolaga Bay.

• Yellow Heavy Rain Watch: Gisborne about and south of Tolaga Bay.

• Yellow Strong Wind Watch: Gisborne north of Ruatoria and Bay of Plenty east of Opotiki.

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
Authorities have warned that State Highway 35 between Tolaga Bay and Ruatoria may be closed at short notice due to the adverse weather. 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.

Resources

New Zealand National Meteorological Service
New Zealand Transport Agency