New Zealand: Heavy rain and strong winds forecast in places July 15-16

Heavy rain and strong winds are likely across the north and upper south regions July 15-16. An active front is forecast to track eastwards across New Zealand July 14, bringing heavy rain and strong winds to the North and South Island areas. The New Zealand National Meteorological Service (MetService) has issued the following weather warnings:

• Orange (middle level on a three-tier scale) Heavy Rain Warning:

  Coromandel Peninsula from 08:00-20:00 July 15. Bay of Plenty, and west of Rotorua from 13:00 July 15-04:00 July 16.

• Yellow Heavy Rain Watch: Northland, north of Whangaparaoa Peninsula, and Auckland from 02:00-16:00 July 15. Tasman District and west of Motueka from 17:00 July 15- 03:00 July 16.

• Yellow Strong Wind Watch: Northland from 01:00-11:00 July 15.

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, and decreased visibility is likely in mountainous areas. Rain-induced landslides are possible in areas of elevated terrain, and avalanches are possible 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 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.