Australia: High temperatures likely to persist over central, eastern, northern, southern, and southeastern regions through at least Dec. 19 /update 1

High temperatures are forecast to persist across parts of central, eastern, northern, southern, and southeastern Australia through at least Dec. 19. Temperatures in excess of 40 C (104 F) are expected across parts of the affected area over the coming days. The Australian Bureau of Meteorology (BOM) has forecast extreme heatwave conditions (the highest level on a three-tier scale) across parts of central and northern Northern Territory and western Queensland through Dec. 19. Severe and low-intensity heatwave conditions are expected over much of the rest of the affected area over the coming days.

As of Dec. 13, the BOM has issued the following heatwave warnings across the affected area:

• Extreme heatwave warnings: Parts of Gregory District in Northern Territory and North West District in Queensland.

• Severe heatwave warnings: Across the Australian Capital Territory District and parts of South Coast, Central Tablelands, Southern Tablelands, Snowy Mountains, Central West Slopes and Plains, South West Slopes, Riverina, Lower Western, and Upper Western in New South Wales; Daly, Tiwi, Arnhem, Carpentaria, Barkly, Simpson, and Tanami districts in Northern Territory; Peninsula, Gulf Country, North Tropical Coast and Tablelands, Herbert and Lower Burdekin, and Channel Country districts in Queensland; Riverland, Mid North, Flinders, North West Pastoral, and North East Pastoral districts in South Australia; and North East and East Gippsland districts in Victoria.

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

The extended period of oppressive heat and dry conditions may produce ideal circumstances for bushfire growth throughout the affected regions. Heatwaves also threaten vulnerable groups - such as the elderly, children, pregnant women, and those with respiratory illnesses - due to the increased possibility of heat stroke or heat exhaustion during prolonged exposure to high temperatures. These health risks could also extend to relatively healthy individuals during significant heatwave events. In addition to significantly impacting athletes and those who work outdoors, high temperatures can cause problems for people using mass transit. The lack of air conditioning and cramped vehicles during rush hour may lead to some passengers' hospitalization.

Very high temperatures may damage road surfaces, and overheated vehicles may worsen traffic problems in urban areas where congestion is already a problem. Commercial trucking disruptions might occur, as very high temperatures put more stress on vehicles, making tire blowouts more common. Major flight disruptions are unlikely at regional airports, but general aviation disruptions are possible, and some airfreight carriers could reduce cargo loads. High temperatures could lead to an increased demand for electricity, which might trigger localized brownouts or blackouts, exacerbating hazardous conditions when air conditioning is no longer possible.