Residents in Western Australia's remote north face a nervous wait amid the formation of Tropical Cyclone Joyce and fears it will grow into an even more severe storm off the west Kimberley coast.
The Bureau of Meteorology warned on Thursday that Joyce was expected to intensify considerably while moving southwest.
A yellow alert to prepare to take shelter is in place for the Kimberley including the tourist areas of Broome and Cable Beach and the Aboriginal community of Bidyadanga.
It is the region's second cyclone in a fortnight after Tropical Cyclone Hilda hit the Broome area.
Authorities are concerned that the longer the system remains offshore the more it will strengthen before potentially hitting populated areas such as Port Hedland in the Pilbara on Friday night or Saturday morning.
Joyce was declared a category one cyclone on Thursday morning with winds of 65kmh but is set to grow to a far more dangerous category three by Friday with winds up to 180kmh.
BoM duty forecaster Noel Puzey says flooding is on the cards with expectations of 50-150 millimetres of rain and isolated falls of up to 300mm.
Department of Fire and Emergency Services regional head Glenn Hall on Thursday ordered the closure of the Great Northern Highway between Port Hedland and Broome for 36 to 48 hours.
Emergency crews have been sent to Broome from Perth while an evacuation centre set up is already providing shelter for almost 150 people.
"Cyclones should never be underestimated; as (Joyce) crosses the coast it will be a severe tropical cyclone," Mr Hall told reporters.
"The winds from that will be destructive, there are no two ways about it, so we need to make sure we are prepared."
Mr Hall also warned against risk-taking during the wild weather amid reports of people planning to go surfing while Senior Sergeant Brendan Barwick of Broome police said residents should refrain from holding "cyclone parties" which have been common in the past.
Cable Beach Caravan Park owner Ron Beacham said it was remarkable to get two cyclones in a little over a week after years of relatively quiet seasons.
Tropical Cyclone Rosita was the last to directly come through Broome in 2000.
While most residents were staying to protect their homes, Mr Beacham said he'd told visitors the best thing to do was get out.
"If you leave five minutes before a cyclone you can out-run them, they only go at 10kmh, you can do 100 so it doesn't take long to get away from them," he told AAP.
Shire of Broome councillor Chris Mitchell, who chairs the local Emergency Management Committee, says most shops and agencies are closed as people batten down.