Australia: Adverse weather forecast across eastern regions through at least early Dec. 1

Severe weather is forecast across much of eastern Australia through at least early Dec. 1. A low-pressure system generating severe thunderstorms passed through South Australia Nov. 28, leaving thousands without power in Adelaide and surrounding areas and disrupting flights at Adelaide Airport (ADL). The system is forecast to continue to move northeastwards over the coming days, with the worst of the severe weather likely in parts of eastern New South Wales (NSW) overnight Nov. 28-29 and in parts of northeastern NSW and southeastern Queensland Nov. 29. Severe thunderstorms could produce heavy rainfall, leading to dangerous and life-threatening flooding. The heaviest rainfall totals over the coming days are expected along the southern coast of NSW. Strong winds, lightning, and possible tornadoes will also accompany storms.

As of late Nov. 28, the Australian Bureau of Meteorology (BOM) has issued the following weather warnings across the affected area:

• Severe weather warning for damaging winds and heavy rainfall: Across South Coast and parts of Illawarra and Snowy Mountain forecast districts in NSW and parts of West and South Gippsland, Central, and South West forecast districts in Victoria.

• Severe thunderstorm warnings: Parts of Channel Country and Maranoa and Warrego forecast districts in Queensland and parts of Illawarra, South Coast, Southern Tablelands, Central West Slopes and Plains, Riverina, Lower Western, and Upper Western forecast districts in NSW.

Marine wind warnings are also in place for many southeastern coastal areas and the following flood warnings have been issued across the affected regions:

• Major flood warnings: The Moonie River in Queensland.

• Moderate flood warnings: Mungallala and Wallam creeks in Queensland.

• Minor flood warnings: The Barcoo River in Queensland and the Paroo River in both Queensland and NSW.

• Flood watch: The rivers of Illawarra Coast, South Coast, Inland Central West, and South West in NSW.

• Initial Flood watch: The rivers of Gippsland and parts of North East and South West in Victoria.

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 or a lack of stormwater drainage systems. Sites located 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.

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.

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

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and employees' inability to reach work sites. Electricity and telecommunications service disruptions are possible where significant flooding, strong winds, or landslides impact utility networks.