The Bureau of Meteorology is warning a category two tropical cyclone off Western Australia's coast is showing signs of rapid development and is likely to intensify swiftly into a category three system later today.

People across a huge slice of the state's Kimberley and Pilbara regions have begun making their final preparations for Tropical Cyclone Ilsa as it bears down on WA.

The latest forecast tracks from the BOM have the cyclone strengthening into a category three system later today before reaching a category four level later this week.

Cyclone Ilsa is currently over waters north of the Kimberley, about 340 kilometres north-west of Broome, heading south-west towards Pilbara coast.

The system is already bringing intense rain and destructive winds of up to 140 kilometres per hour.

A cyclone watch extends from Beagle Bay to Whim Creek past Port Hedland and inland areas to Telfer.

BOM duty forecaster Jessica Lingard said the cyclone was starting to impact both inland and coastal areas.

"This isn't just a coastal hazard, obviously the coastal areas will get the full force of the system, but inland it is still expected to be a category two system as it whizzes past Telfer," she told ABC Radio Perth.

Landfall due between regional centres

After making steady progress along the Kimberley coast since the weekend, the system reached tropical cyclone strength yesterday, and is expected to make landfall between Port Hedland and Broome on Thursday or Friday.

While severe weather is expected to begin impacting remote communities along the Dampier Peninsula, north of Broome, from today, conditions are set to grow more severe as the system edges closer to land.

BOM spokesman Todd Smith said coastal communities could be hit with gale-force winds, heavy rain and storm surges.

"We're expecting it to take a turn to the south [today], before moving south-east on Thursday," Mr Smith said.

"The damaging winds and heavy rainfall will extend many hundreds of kilometres inland."

Authorities were expected to begin clearing the Port of Port Hedland overnight.(Supplied: Pilbara Ports Authority)

In Port Hedland, authorities were due to begin clearing the town's inner harbour — the nerve centre for WA's iron ore exports — early this morning.

Fears of 'pretty savage' impact

Arnold Carter has lived in the port town for 65 years and Ilsa will be his 28th cyclone.

"If it does happen to cross the coast over Port Hedland, believe me, it'll be pretty savage," Mr Carter said.

He raised concerns that residents might be ill-prepared for the cyclone, given its arrival so late in the season.

Long-time Port Hedland resident Arnold Carter has lived through 27 cyclones in his 65 years in the town.(ABC Pilbara: Amelia Searson)

"As soon as the red alert goes, what a rummage it's gonna be for the local stores," he said.

"I've seen it happen on many occasions and everybody gets roaring down there and … the shop is empty."

Mr Carter's advice was, "Do the shopping now", and top up with water.

"If you've got a boat, fill it with water, if you've got a bath, fill it with water, because if water goes out … you've got real damage," he said.

He said it was difficult to compare cyclones, but his only hope was to never get an equivalent to Cyclone Joan, which ravaged the town in 1975.

Enough food and fuel to last seven days has been shipped into Bidyadanga ahead of the cyclone.(Supplied)

Extra resources for Bidyadanga

Bidyadanga, 180km south of Broome, is WA's largest remote Aboriginal community and the closest town to the expected track of the cyclone.

Food and fuel to last the community seven days has already been shipped in, with several residents requiring medical treatment evacuated to Broome.

Community chief executive Tania Baxter said residents were used to dealing with cyclones, and felt well-prepared for the days ahead.

"We've been doing cyclone clean-up since forever, we do it all the time; we did tree lopping earlier and at the start of the wet season," she said.

"For us today and tomorrow, it'll just be about any extra cyclone clean-up, basically anything around the streets that we think we can pick up and get out to the tip."

Ms Baxter said the community was working with emergency services to understand the impact of the system as it tracks over.

"It depends on how we weather it … maintaining power supply is essential because that also maintains our water," she said.

DFES Commissioner Darren Klemm said maintaining the community's power supply was a key priority as the system tracks closer.

Parts of Broome are vulnerable to flooding during storm surges and heavy rain.(Supplied: Lauren Hall)

Concern for rough sleepers in Broome

Further north in Broome, concerns have emerged for the large number of rough sleepers staying in town — including people left homeless by the catastrophic flooding in January.

The Kullari Patrol, which supports people sleeping rough and in need of assistance in town, said it was critical updates on the cyclone reached people without access to phones or other communications.

Spokesperson Cassandra Baleilau said people without access to the latest information could be left even more vulnerable.

With a formal alert needing to be issued before cyclone shelters open, she said authorities should consider issuing a blue alert for Broome as early as possible.

Commissioner Darren Klemm said DFES was working closely with local governments around the timings of alerts and ensuring vulnerable populations were being looked after.

Inland communities begin preparations

With the system likely to bring gale force winds and heavy rain inland into the weekend, remote communities, stations and mine sites across the Pilbara are all closely watching its path.

Authorities have reached out to a number of smaller communities to determine current population levels and whether people will need evacuation, potentially to larger centres such as Marble Bar.

In Punmu, 640km south east of Port Hedland, co-ordinator Paul Brann said children were being evacuated from the community, along with others who wanted to go.

He expected about 10 adults would remain in the community during the coming wild weather, where they had plenty of supplies and cyclone-rated accommodation.

The population at Punmu Community (pictured) is lower than normal due to a number of residents being away on cultural commitments.(Supplied: Donald Graham)

"Prepare for the worst and hope for the best," Mr Brann said.

"We've got enough fuel to generate power for about 80 days. We've got a large freezer full of food.

"We're pretty well prepared — we'll just bunker down and see it out."

Mr Klemm said mine sites across the region — including Newcrest's huge Telfer Gold Mine near Punmu — would make their own preparations and decisions around whether evacuations would need to take place.

A Newcrest spokesperson said the site's normal workforce — 960 people between Telfer and the nearby Havieron project — had been reduced to essential staff only.

"Those who are being asked to demobilise from site are being flown back to Perth, with a view to remobilising them as soon as it is safe to do so," they said.

"Our first and foremost priority is people's safety, and we will continue to be guided by forecasts and warnings issued by the Bureau of Meteorology regarding any further actions — which may include reducing staffing levels onsite even more."

Source: ABC News