Much of the country is set to be drenched this week, with meteorologists warning a “La Nina-like” weather system could dump heavy rains across all major cities.
Meteorologist Ben Domensino said the rain will be caused by a negative Indian Ocean Dipole (IOD) and a positive Southern Annular Mode, while a broad low-pressure trough and cold front mixed with an unstable atmosphere will cause widespread thunderstorms.
The uncharacteristic Winter thunderstorm outbreak will likely hit this afternoon and early evening after storms stretched 3000km across most of the country early this morning.
Thunderstorms and heavy rains are likely in seven states later this afternoon and evening, with flood watches issued in parts of Victoria.
The most intense thunderstorms are likely to hit Monday afternoon, with storms likely to continue in parts of the NT, Queensland, NSW, and Victoria tomorrow.
The flood watch includes minor warnings across the Kiewa, Latrobe and Yarra Rivers.
Storms and rains will likely impact parts of the Northern Territory, Queensland, New South Wales, the ACT, Victoria, South Australia, and Tasmania with warnings of damaging winds, large hail, and heavy rain.
Supercell thunderstorms could also trigger destructive winds and giant hail across western New South Wales later today.
“Monday’s storms are being caused by a broad low pressure trough and cold front interacting with moisture-laden air and an unstable atmosphere,” Domensino said.
This instability is being enhanced by a large temperature contrast between an unseasonably warm air mass over the Australian continent encountering a much colder pool of air travelling up from the Southern Ocean.”