UPDATED: RESIDENTS are in lockdown and emergency welfare centres have opened in Western Australia's North West as severe tropical cyclone Christine bears down on the Pilbara.
The Category 3 storm crossed the coast between Whim Creek and Roebourne overnight around midnight, and is expected to take a more southerly track during the next six hours.
The Bureau of Meteorology said Christine was estimated to be 200km southwest of Port Hedland and 80km south southeast of Karratha and moving south southwest at 16km/h.
Very destructive winds with gusts in excess of 170km/hour are possible near the centre over the next few hours.
Destructive winds with gusts in excess of 130km/hour are expected to extend well inland during Tuesday.
Gales with gusts to 115km/hour are occurring between De Grey and Mardie and will extend to the inland Pilbara during the remainder of Tuesday morning.
Widespread heavy rainfall is expected near the cyclone track and flood warnings have been issued for the Pilbara.
Gales with wind gusts to 100km/hour should extend into the eastern Gascoyne, far western Interior and the northern Goldfields before the cyclone weakens late Tuesday or early Wednesday.
DFES State Emergency Service (SES) advises of the following community alerts:
Red Alert: People in or near coastal areas between De Grey and Mardie, including Port Hedland, South Hedland, Whim Creek, Roebourne, Point Samson, Wickham, Karratha and Dampier also extending inland to Tom Price and Paraburdoo.
Yellow alert: People in inland areas including Marble Bar and Pannawonica.
Blue alert: People in or near coastal areas between Mardie and Onslow and the inland area from Marble Bar to Newman and between the Collier Ranges and Three
Rivers incluiding Kumarina and east to Granite Peak.
Up to 85 people in Port Hedland have sought shelter at the JD Hardie Centre, Cottier Drive in South Hedland as the wind and rain builds in strength.
The Department for Child Protection and Family Support has opened emergency welfare centres at the Karratha Leisureplex on Dampier Highway, adjacent to Broadhurst Road in Karratha.
An emergency welfare centre for Marble Bar opened later Monday at the Civic Centre, 24 Francis Street in Marble Bar.
Hedland resident Sarah Smith updated Fairfax Media via text message of the cyclone's progress.
"The wind gusts are picking up now and rain [is] intermittently getting heavier," Sarah wrote.
"When gusts are happening the roar is starting but otherwise not too bad here.
"Power has already gone out in some area but so far we are luck and still have power and Foxtel (smiley face)."
A BHP Billiton spokeswoman said Port Hedland port and rail operations were suspended and all workers had safely left its sites.
"BHP Billiton Iron Ore continues to closely monitor tropical cyclone Christine and to work with the relevant emergency service agencies as it approaches the Pilbara coast.
"Our highest priority is to ensure the safety of our people.
"Extreme weather preparations continue across our mining operations in line with alerts issued by the Department of Fire and Emergency Services."
Rio Tinto said ship loading and rail operations have been suspended, with all staff at the port sent off site for their safety.
The company's inland mine operations continue as normal.
Fortescue Metals Group said its Port Hedland operations and rail operations had been secured, in line with the company's cyclone readiness procedures.
"Conditions are being closely monitored and plans will be updated accordingly," the company said.