11 Feb 2022 | 06:59 AM UTC
New Zealand: Adverse weather forecast to continue in central and northwestern regions through at least Feb. 13 /update 6
Further severe weather forecast across central and northwestern New Zealand through at least Feb. 13. Disruptions possible.
Event
Further heavy rainfall and strong winds are forecast across central and northwestern New Zealand through at least Feb. 13. The affected areas include Auckland, far northeastern Canterbury, southern Hawke's Bay, Manawatu-Wanganui, Marlborough, Nelson, Northland, Taranaki, Tasman, southern Waikato, Wellington, and northeastern West Coast regions. The heavy rainfall is likely to cause rapid water level rises in streams and rivers. Localized flooding and landslides are likely. The rain might result in hazardous driving conditions.
As of Feb. 11, the New Zealand National Meteorological Service (MetService) has issued the following warnings and watches:
Orange (middle level on a three-tier scale) heavy rain warning: Bryant Range, Horowhenua, Kapiti, Marlborough Sounds, Rai Valley, Richmond Range, Taranaki, Tararua Range, Tasman west of Motueka, Tongariro National Park, Wairarapa, and Wellington; the heaviest rainfall is forecast over the Tararua Range with 20-30 cm (8-12 inches) and over the Tongariro National Park with 17-25 cm (6.5-10 inches) of rain. Up to 20 cm (8 inches) of rain is forecast over the rest of the orange warning area.
Yellow heavy rain watch: Buller ranges, Canterbury north of Waipara, the rest of Marlborough, ranges of Nelson Lakes, Taihape, Taumarunui, southern Taupo, the rest of Taranaki, Tararua District, Waitomo, and the rest of Whanganui and Manawatu.
Yellow strong wind watch: Auckland, Buller, Marlborough Sounds, Northland, Taranaki, Tasman, and Wellington.
A local state of emergency is in place for the Buller District. Authorities evacuated 121 residents from Westport Feb. 10 due to the likely flooding of low-lying areas from heavy rain coinciding with high tide; as of early Feb. 11, residents have since been allowed to return home. At least five houses in Mohikinui township were damaged by the floods. The water infrastructure in Waimangaroa has sustained significant damage; authorities have established an emergency water supply for residents.
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 heavy rainfall has saturated the soil. 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 some delays and cancellations at regional airports. Authorities may temporarily suspend port operations along the Tasman Sea 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 experience heavy rainfall and potential track blockages. State Highway 67 from Karamea to Mokihinui and Westport to Mokihinui remains closed due to multiple landslides. Authorities estimate that the road will be reopened 09:00 Feb. 12. State Highway 7 at Lewis Pass and State Highway at Shenandoah are also closed.
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.
