New Zealand: Severe weather forecast across central and western South Island through at least April 11

Severe weather is forecast across central and western South Island through at least April 11. A front is forecast to track northwards over Fiordland April 9, and become slow-moving over Westland April 10-11. Periods of heavy rain are likely over Fiordland and Westland, and strong north to northwest winds over Fiordland and the Canterbury High Country. As of April 8, the New Zealand National Meteorological Service (MetService) has issued the following weather warnings:

• Orange Heavy Rain Warning (middle level on a three-tier scale): Fiordland about and north of George Sound, headwaters of the Otago lakes and rivers, and Westland District south of Hokitika. Up to 25 cm (10 inches) of rain is forecast.

• Yellow Heavy Rain Watch: headwaters of Canterbury lakes and rivers, Fiordland south of George Sound, Grey District, and Westland District about and north of Hokitika.

• Yellow Strong Wind Watch: Canterbury High Country and Fiordland.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

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 stormwater drainage systems. Sites 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 rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are likely where significant flooding or landslides impact utility networks.

Floodwaters and debris flows will likely render some bridges or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces will probably cause hazardous driving conditions on regional highways. Authorities are likely to close some low-lying routes that become inundated by floodwaters temporarily. Flight delays and cancellations at airports are probable.

Localized business disruptions are likely in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.