A major storm system bearing down on millions of Western Australians on Saturday is bringing cyclone-strength winds, and is set to deliver a “wintry blast” to the east of the country early next week.

Residents across WA’s populated south-west were warned to tie down loose items and prepare for destructive wind gusts that could exceed 125km/h from Saturday evening.

The Bureau of Meteorology warned that along with the damaging winds could come thunder storms, heavy downpours, flash flooding, damaging surf and a risk of tornadoes.

Wind gusts higher than 125 km/h are typically associated with category two cyclones.

While early winter storm systems are not new for the region, Daniel Hayes at the bureau warned “this one looks quite significant.”

A deep low pressure system – where air is rising – was moving towards the WA coastline on Saturday and would bring the strong winds and was dragging tropical moisture with it to bring heavy downpours.

A bureau warning covering the entire south-west of WA was in place on Saturday morning. Residents were told to prepare properties and tie-down any loose items.

Six-hourly rainfall totals of up to 60mm were predicted in central west areas of the region from late Saturday until early on Sunday.

The entire south-west coastline was also under a warning for abnormally high tides and damaging surf.

From Sunday morning, low-lying areas could see flooding and residents were warned to stay away from surf and exposed areas.

A second round of wind gusts up to 125 km/h were expected on Sunday night between Lancelin and Albany, including Perth.

Hayes said residents in South Australia and in Alpine areas of Victoria would likely be under further warnings by Sunday as the system moved east.

“By Monday we are seeing impacts across to South Australia and later on Monday and Tuesday some of that rain and wind is picking up in parts of Victoria and New South Wales.

“Once that front moves through we start to see a pronounced wintry blast. It’s going to feel noticeably cool with these strong winds.”

Wind gusts of 50 km/h were forecast for Melbourne on Monday evening. Hayes said there could be snow falls in alpine areas early next week.

But he said the system’s connection to tropical moisture would break down as it moved east, reducing the amount of rain it could bring.

While the conditions would herald the arrival of winter, the bureau’s long-range forecast for winter shows the southern two-thirds of the country will be warmer than average.

That forecast also accounts for developments in the tropical Pacific ocean, where meteorologists are watching for the likely development of an El Niño this winter.

Previous El Niños have brought warmer and drier conditions to Australia’s east during spring periods.

The phenomenon can push up global temperatures and experts have said the system, when combined with global heating, could see 2027 become the hottest year on record.