Tropical Cyclone Veronica remains a category four system as it travels closer to Western Australia's northern coast but may temporarily intensify to a category five.
The Bureau of Meteorology says the Pilbara region is likely to be impacted from late Saturday afternoon and on Sunday.
"While the cyclone may weaken before reaching the coast, a severe coastal impact is likely."
Pictures circulating on social media show supermarket shelves in the region bare.
Many supermarket shelves in the region are empty as residents prepare for Cyclone Veronica Source: Twitter: @nat_forrest
Gales with gusts to 100km/h may develop between Pardoo and Mardie on Friday evening, and may extend farther east to Wallal Downs, farther west to Onslow and extend to inland areas including Pannawonica and Marble Bar later on Saturday.
Destructive winds with gusts exceeding 125km/h are forecast to develop along the coast between Dampier and Pardoo later on Saturday.
Heavy rain is expected to trigger significant widespread flooding from late Saturday.
A Blue Alert is in place for people in or near communities between Mardie and Wallal, including Port Hedland, South Hedland, Wickham, Roebourne, Point Samson, Karratha, Dampier, Barrow Island, Pannawonica and Marble Bar.
The Pilbara Ports Authority has cleared all large commercial vessels from the harbours and anchorages at the Ports of Dampier, Port Hedland and Ashburton.
The WA Country Health Service says procedures are in place at Karratha and Hedland Health Campuses, as well as Onslow Health Service, so they can continue operating during the cyclone.
Staffing, supplies including food and pharmaceuticals, and plans for high risk patients have been prepared.
"Once the facilities move to a Yellow Alert, emergency department services and inpatient care will continue, however all outpatient hospital, allied health and nursing appointments will be cancelled," a spokeswoman said.
"Once a Red Alert is notified, Karratha and Hedland Health Campus emergency departments will continue to operate, as will Onslow Health Service, while Roebourne Hospital will be closed.
"The facility will be reopened once the red alert is lifted."
The last category four tropical cyclone to impact the WA coast was Christine in December 2013.
Veronica is the third tropical cyclone for the season.
