New Zealand: Severe weather forecast across northern parts of North Island through at least Dec. 21

Severe weather is forecast across northern parts of North Island through at least Dec. 21. Heavy rainfall and thunderstorms are expected around the Bay of Plenty and Coromandel Peninsula; strong wind gusts, lightning, and hail may accompany storms. rainfall totals of 8-12 cm (3.1-4.7 inches) are possible in the Bay of Plenty area. Heavy downpours may trigger flooding in low-lying areas and landslides on unstable slopes.

As of early Dec. 21, the New Zealand National Meteorological Service (MetService) has issued the following weather warnings across the affected area:

• Orange Heavy Rain Warning (the middle level on a three-tier scale): Bay of Plenty.

• Yellow Heavy Rain Watch: The Coromandel Peninsula.

• Yellow Severe Thunderstorm Watch: Great Barrier Island, Coromandel Peninsula, Bay of Plenty, and Rotorua.

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 rainfall has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Where significant flooding, landslides, or strong winds impact utility networks, disruptions to electricity and telecommunications services are possible.

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 airports in the affected regions. Flooding could block regional rail lines; freight cancellations are possible in areas with heavy rainfall and potential track blockages.

Localized business disruptions are possible in areas impacted by severe weather; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites.