The engine room of the State's economy is expected to go into lockdown today as tropical cyclone Rusty zeroes in on the Pilbara.
Modelling suggests the system will reach at least category three intensity and make land near Pardoo, 150km east of Port Hedland, late tomorrow night or early Wednesday.
But a more westerly crossing has not been discounted and the world's biggest bulk export port was taking no chances yesterday.
Ships at anchor were ordered to evacuate and inbound movements suspended.
Complete shutdowns at BHP Billiton and Fortescue Metals Group's Port Hedland operations are expected to follow.
Coastal communities between Karratha and Broome were reporting gales last night.
The Weather Bureau said Rusty had a big radius with maximum winds of about 100km/h, meaning the strongest gales could be some distance from the centre.
Pardoo Roadhouse manager Gareth Gates said he was surprised at wind strength yesterday given the system was more than 48 hours away.
"It's already gale force out here at the moment," he said. "It's blowing up a storm but there's no rain.
"All our loose stuff outside has been put away and we're no longer taking guests. We're not quite sure yet if the staff will stay here and ride it out.
"It depends how close it's going to be to us."
Motorists are warned of road closures in the Kimberley and Pilbara.
Department of Fire and Emergency Services Kimberley district officer Matt Reimer said Rusty was forecast to bring heavy rain over the next two days.
"Along its path, we are expecting between 400mm and 600mm a day," he said. "If that does happen, it will probably cause road closures in the Pilbara, maybe even the Great Northern Highway. That is a concern we are planning for at this stage, in addition to any potential cyclone impact."
Mr Reimer said Broome had escaped mostly unscathed so far but strong wind gusts and heavy rain began hitting on Saturday afternoon.
"In Broome, we are expecting between 50mm and 100mm a day over the next couple of days," he said.
Mr Reimer said emergency crews were called to a house in Broome on Saturday night after a tree was blown on to it.
Early this morning the Department of Fire and Emergency Services issued a BLUE ALERT for Broome to Whim Creek, including people in or near Port Hedland and Wallal.
A cyclone watch is current for people in or near the coastal communities of Whim Creek to Mardie, including Karratha and Dampier, extending inland to Marble Bar and Millstream.
Tropical Cyclone Rusty is about 315km north of Port Hedland and 420km west of Broome. It is moving south at 6 kilometres per hour.