Damaging winds and heavy rain are battering the West Australian coast between Dampier and Port Hedland as Cyclone Veronica edges slowly towards the Pilbara coastline.
A red alert has been issued for people in or near communities between Pardoo and Mardie, including Port Hedland, South Hedland, Whim Creek, Point Samson, Wickham, Roebourne, Karratha and Dampier.
The Bureau of Meteorology has warned that a severe coastal impact is expected later today, with residents being urged to brace for torrential rain, a damaging storm surge and destructive winds for 12 hours or more.
The category three system to is expected to strengthen back to a category four system before crossing the coast on Sunday, bringing with it destructive wind gusts in excess of 165 kilometres per hour.
Authorities have warned there is a threat to lives and homes, and those affected are being urged to seek shelter immediately.
A yellow alert remains in place for those in or near remaining communities between Wallal and Pardoo and inland to Marble Bar.
Gales with gusts to 100 kilometres per hour have developed between Port Hedland and Dampier, and may extend to other coastal communities between Wallal and Mardie by Sunday afternoon.
Port Hedland residents are likely to be most at risk, with much of the town expected to be hit by storm-surge flooding.
Authorities are warning the surge may be up to four metres on top of the existing tide level, and tides are already at their highest point this weekend.
Residents urged to stay indoors
Department of Fire and Emergency Services (DFES) superintendent John Newman said people needed to be prepared for lengthy periods of destructive winds.
"We're expecting destructive winds to arrive in the area between midnight and 1:00am [Sunday], and the bureau advises we should be under the influence of destructive winds for a period of 24 hours," he said.
"The bureau has advised that if the cyclone moves further to the east it could pass directly over Port Hedland.
"That will mean Port Hedland could be in the eye of the cyclone for up to eight hours.
"It's very important that during this period of calm people remain inside because without notice the cyclone could very, very rapidly bring the town back into destructive winds as it passes over."
DFES said the red alert would probably be in place longer than usual, and residents should expect the environment during that time to be unpleasant.
The town's Mayor, Camillo Blanco, urged residents in affected areas to relocate before the cyclone hit, if they had not already done so.
"People in low lying areas of Port Hedland should make those arrangements now before it is too late," he said.
"We do not have the resources in the emergency services to come and get you if things go pear-shaped in the middle of the cyclone."
Police witness 'idiotic' behaviour
WA Police Inspector Craig Parkin also urged local residents to heed the warnings.
"If you have been visited by police in the past 24 hours, you are considered a person or a property at risk," he said.
"You need to leave your property and relocate over to South Hedland with friends or family or into the emergency centre, which is set up to cater for a number of days.
"We are already seeing behaviour which I would classify as idiotic — where the rains and tides have started we've seen families with young children along the foreshore.
"Police will be patrolling the area until the red alert begins.
"Following that that if you place yourself at risk, the emergency services will not be in a position to come and rescue you."
Hazardous waterways and dangerous storm surges
BOM has warned residents to expected significant rainfall, which is likely to cause flooding.
"We're expecting widespread totals of 100 to 300 hundred millimetres along the coast between Karratha and Wallal Downs," Mr Stewart said.
"So that will lead to significant flooding, which will make conditions on the road and even waterways extremely hazardous."
A flood warning has been issued for the Pilbara Coastal Rivers.
The system is also expected to create dangerous storm surges that are likely to cause significant flooding and could see parts of Port Hedland become temporary islands as low lying areas are inundated.
Residents head to evacuation centre
The evacuation centre in South Hedland has been filling with people.
A small army of volunteers has set up bedding and support services, while volunteers have been delivering enough food, water and toiletries to last several days.
"I just volunteered last night, we were talking about it and they didn't know how they were going to get the gear over here," volunteer Jason Maracic said.
"Me and another bloke, with two trucks, sent one to Coles and one to Woolworths just to make it a bit easier for them."
Kirk Morrison was among those staying at the centre and said having spent most of his life in the north-west, that it was not his "first rodeo" when it came to cyclones.
But Mr Morrison said it was his first cyclone with a wife and children, and he had decided the evacuation centre was the safest place for his family to be.
"My wife is panicking a little because she is pregnant, but my son doesn't seem too worried about it. He's quite chill," he said.
"But there's definitely enough shelter. It's a well-built building, it's rated to a five, so it's safe."
German backpacker, Clarissa Widder, had planned on spending just one night in Port Hedland on her way to Broome.
She said she soon realised she would be in Port Hedland for a number of days with most major roads closing.
Ms Widder made the decision to head to the centre when it became clear camping was no longer going to be an option.
"I think a tent is not really good now," she said.
A blue alert is current for people in parts of the inland Pilbara, including Pannawonica and Nullagine.
A number of roads have been closed to all traffic, including:
The following roads will be closed once a red alert is issued: