16 Oct 2023 | 02:24 AM UTC
New Zealand: Heavy rain, snowfall, and strong winds forecast across southern and central regions through at least Oct. 17
Heavy rain, snowfall, and strong winds forecast across southern and central New Zealand through Oct. 17. Disruptions likely.
Event
Heavy rain, snowfall, and strong winds are likely across southern and central regions through at least Oct. 17. The New Zealand National Meteorological Service (MetService) has issued the following weather warnings as of the afternoon of Oct. 16:
Orange (middle level on a three-tier scale) Heavy Rain Warning: Headwaters of the Canterbury lakes and rivers about and south of Arthur's Pass, Tasman about and west of Motueka, Nelson Lakes, Buller and Grey districts, and Westland south of Otira. Rainfall of up to 18 cm (7 inches) is forecast, with possible thunderstorms.
Yellow Heavy Rain Watch: Headwaters of the Canterbury lakes and rivers north of Arthur's Pass, Marlborough northwest of Awatere Valley, and Tasman east of Motueka, excluding Nelson Lakes.
Yellow Heavy Snow Watch: Mackenzie Basin.
Yellow Strong Wind Watch: Canterbury High Country, Marlborough, Wairarapa south of Carterton, and Wellington.
Road Snowfall Warning: Lindis Pass (SH8), Arthur's Pass (SH73), Porters Pass (SH73), Milford Road (SH94), and Crown Range Road.
Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Where precipitation falls as rain, flash and areal flooding is possible. This may occur in low-lying communities near watercourses and other large bodies of water and in urban areas with easily overwhelmed stormwater drainage systems. Sites downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall.
Precipitation could fall as snow in the higher elevations over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides are possible in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Power outages are likely throughout the affected area.
Floodwaters and related debris will likely render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas will probably cause significant traffic congestion. Heavy snow will make driving hazardous in some areas; authorities will likely implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.
The disruptive weather will likely cause additional delays and cancellations at airports across the affected region. Authorities will probably suspend port operations temporarily if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding/snow will likely block regional rail lines, causing freight and passenger train delays and cancellations.
Disruptions triggered by inclement weather and resultant hazards, such as flooding or avalanches, will likely persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. Repair or reconstruction efforts may result in residual disruptions if there is severe damage to infrastructure.
Advice
Monitor local media for weather-related updates and advisories. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible delivery delays throughout the affected area. Allow extra time to reach destinations and carry an emergency kit and warm clothes if driving is necessary, especially on secondary or rural routes that could become impassable. Charge battery-powered devices in the case of prolonged electricity outages.
