Western Australia braces as our most severe storm in 10 years prepares to lash the state

West Australians have been urged to “bunker down” ahead of Sunday and Monday’s severe weather event, which the Bureau of Meteorology says will be the biggest and most severe storm the State has seen in a decade.

The “very rare event for WA”, expected to bring with it dangerous wind gusts of up to 130km/h and heavy rain, will descend on the west coast from early this morning in the Gascoyne Region, after which it is forecast to spread south.

Duty forecaster Angus Moore said BoM’s warning area, from Kalbarri to Albany, was “massive”, making it “very difficult to know for sure where exactly the worst” of the storm was going to hit, and when.

“The general consensus is that we’ll start to see very windy conditions developing up around the Ningaloo coast and Gascoyne coast from about 5am Sunday and that weather will then start to intensify and move rapidly down the coast,” he said.

“Those conditions will start ramping up and develop down the west coast, so in terms of the South West, things could get significantly more intense ... the biggest impact ... is expected Sunday afternoon and evening.”

While wind gusts up to 100km/h are forecast for almost the entire west coast today and tomorrow, isolated wind gusts as high as 130km/h are predicted for some areas along the coast.

BOM state manager James Ashley warned “the whole west coast is at risk with this event”, which won’t ease off until Monday afternoon.

In addition to securing their homes, he asked West Australians to stay out of the water, with damaging surf conditions and peak wave heights of up to 8m expected.

Department of Fire and Emergency Services Chief Superintendent Jon Broomhall said the deep, low pressure system, brought on by tropical cyclone Mangga, could trigger flash flooding in low lying coastal areas and would “test people’s buildings, sheds and all those unsecured items”.

This is going to come from the north-west . . . so it definitely stands out from other storms.

He assured residents additional crews and volunteers were on standby, and that assistance from the Australian Defence Force had been organised, should the help be needed.

“We haven’t yet requested interstate assistance, we’ll wait and see what the impact is, but we have had discussions already with the Australian Defence Force locally, for what they can help us with,” Supt Broomhall said.

“Normally our storms comes from the south-west, this is going to come from the north-west ... so it definitely stands out from other storms.”

He urged people who travelled to the south-west for the weekend to “come home early”, while there was still time, but not to drive through the storm.

“Get back here as soon as you can and get your property ready,” Supt Broomhall said, adding the advice was only for those in the south-west, where the storm is expected to reach its peak from late this afternoon.

The wild weather will bring with it heavy and widespread rain, with isolated falls of up to 100mm expected in coastal areas from Cape Leveque and Broome down to Kalbarri.

Heavy rain is also likely down the west coast from Kalbarri to Albany, with totals of around 20-30mm and some isolated falls up to 70mm, while rainfall totals in the Pilbara and western Kimberley coastal areas likely to be around 20-40mm.

Many agricultural areas are likely to receive between 10-20mm of rain.

The closest comparison to this storm is a 2012 weather event that prompted more than 600 calls for help and 170,000 homes losing power.