Tropical Cyclone Dianne expected to form at 8pm before hitting WA coast on Saturday
The Bureau of Meteorology issued this cyclone track map on Friday at 2.52pm. (Supplied: Bureau of Meteorology)
In short:
The Bureau of Meteorology says there is a high chance tropical low 28U will form into a cyclone off Western Australia's north coast about 8pm on Friday.
A category one system is projected to cross the Kimberley coast at around 2am on Saturday morning.
What's next?
The weather system is expected to bring wind gusts of 100km per hour, with residents in Derby and West Kimberley communities and islands asked to prepare.
The Bureau of Meteorology (BOM) says Tropical Cyclone Dianne is expected to form around 8pm on Friday evening off the Kimberley coast in Western Australia.
Weather details released on Friday afternoon showed tropical low 28U would develop into a category one cyclone and was about 280 kilometre north of Derby.
The system has increased from 13 kilometres per hour to 17kph.
Residents will be able to get sand and sandbags in Derby on Friday between 3:30pm and 5:30pm.
The sand will be available at the SES unit in Derby on the corner of Sutherland Street and Derby Highway.
The BOM says it expects a cyclone to form south of Kuri Bay on Friday night, before crossing the Kimberley coast at about 2am on Saturday morning.
Senior forecaster Luke Huntington says it is set to be a category one system when it reaches the mainland, between Derby and Kuri Bay.
The weather bureau said there was an "outside chance" it could develop into a category two system.
"It's not going to last very long, so probably going back to a tropical low by Saturday morning, so a very short-lived tropical cyclone," he said.
Damaging wind gusts of up to 100 km per hour are likely to develop in coastal areas and the system is expected to bring significant rainfall.
"Around 100 to 150 millimetres forecast for today [Friday] and then over the weekend it will move through the inland Kimberley towards Fitzroy Crossing, delivering more heavy rainfall," Mr Huntington said.
The potential area impacted spans from Troughton Island to Beagle Bay on the Dampier Peninsula, north of Broome.
Derby is the town with the largest population in the area included in the warning.
Once the system crosses land, it is expected to weaken and move south east towards the Central Kimberley into the weekend.
Wet weather and flash flooding
The Department of Fire and Emergency Services has asked West Kimberley residents to prepare and get ready for dangerous weather.
Kimberley Superintendent Leon Gardiner said flash flooding was expected into the weekend.
"It's important people start to think about their plans over the next 24 to 48 hours, and minimise any unnecessary travel through that area," he said.
"If you find yourself coming up against a flooded roadway or flooded creek, we really encourage people not to drive, walk, run, swim or play in those flood waters.
"It doesn't take much to wash a car off a floodway and sometimes that unknown depth is where the risk is."
Leon Gardiner is encouraging residents to prepare ahead of a possible category one crossing. (ABC Kimberley: Andrew Seabourne)
Mr Gardiner said while authorities were not expecting "any major isolations", DFES had been in touch with remote coastal communities and offshore mining operations at Koolan Island and Cockatoo Island.
"They're all enacting their cyclone plans and sometimes that means for a system like this, they'll leave staff in situ and onsite, but they're enacting their plans and preparing all of their relevant structures and facilities," he said.
"Some staff will remain on site … they're well prepared, they've got good food stocks and a cyclone shelter and those sorts of things, so they will manage their operation as the risk starts to move through there today."
Leon Gardiner says authorities have been in touch with remote communities and offshore miners. (ABC Kimberley: Andrew Seabourne)
A spokesperson for Mount Gibson Iron, which runs a mining operation on Koolan island, 140 kilometres north of Derby, said they anticipated minimal impact beyond typical wet season weather.
"At this time, site operations are continuing, other than ship loading, which has been temporarily paused," they said.
The impending wet weather has been welcomed in some quarters, with a Fitzroy Crossing pastoralist saying rainfall would be a boost after a couple of dry months.
Derby resident Karen Rule said the community was "excited about a bit more rain."
A storm rolling over the Kimberley town of Derby on Thursday night. (Supplied: Karen Rule)
She said most people had stocked up for the wet season and were now busy tidying yards and moving boats to minimise the risk of damage.
"What we are hoping for is lots of rain in the catchment area so the river flows and less damage around the towns,"Ms Rule said.
Ms Rule said the close-knit community was aware of the warnings.
"Hopefully, everybody got the message already and hasn't gone out (on the water), because our big tides make it hard to get in and out," she said.
Should the cyclone form, it will be named Dianne, the first to cross the Kimberley coast this wet season.