New Zealand: Severe weather forecast across northern parts of North Island and northwestern parts of South Island through at least July 20

Severe weather is forecast across northern parts of North Island and northwestern parts of South Island through at least July 20. A deep subtropical low is forecast to pass northeast of North Island, bringing heavy rainfall to the affected areas.

As of July 19, the New Zealand National Meteorological Service (MetService) has issued the following weather warnings across the affected areas:

• Orange Heavy Rain Warning (middle level on a three-tier scale): Tairawhiti/Gisborne north of Gisborne City. Rainfall totals of 7-9 cm (2.8-3.5 inches) are forecast in the area.

• Yellow Heavy Rain Watch: Northland, Auckland north of Whangaparaoa Peninsula including Great Barrier Island, Coromandel Peninsula, Bay of Plenty west of Whakatane, and Tasman west of Motueka.

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. Adverse weather conditions could also cause power outages throughout the affected area.

The severe weather could contribute to transport disruptions throughout the region. Traffic and commercial trucking delays might occur along regional highways. Strong winds might pose a hazard to high-profile vehicles. 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.

Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and potential track inundation.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved - it could take days before floodwaters recede and/or officials clear debris. Repair or reconstruction efforts may result in residual disruptions if there is severe damage to infrastructure.