The risk of heavy weather was likely to develop on Saturday evening, escorted by a cold front sweeping the continent from west to east, Bureau of Meteorology senior forecaster Miriam Bradbury said.
"Storms are possible across a great central band of the country, extending from the Kimberley ... all the way down into Victoria," she said.
"We're also possibly going to see some storms about parts of the central Queensland coast."
Severe storms triggering high winds, giant hail and flash floods were possible for SA's northwest pastoral and west coast districts into Sunday, while similar conditions were probable for central and northern Victoria and into the NSW Riverina later in the day.
To the north, Ms Bradbury warned the Brisbane area, the Sunshine Coast and the Gold Coast were also in for a torrid time.
"All may see severe thunderstorms ... but the most likely risk for severe storms is slightly removed from the coast," she said.
"It's definitely a good idea to be keeping an eye on the radar and the warnings page tomorrow, with the risk of severe storms over so many populated areas."
Wherever severe storms were forecast, Ms Bradbury said hazards including damage to property, trees and power lines were possible, along with closures and detours as water or debris moved across roads.
Damp conditions are expected to linger along much of eastern Queensland next week as a low-pressure trough continues to draw in moisture against the coast.
Tuesday is likely to be the wettest day.
