A tropical low gathering steam off the northern WA coast could turn into a category 2 cyclone which hits on Thursday evening or Friday morning, while gale-force winds could be affecting townships as early as Wednesday night.

A blue alert was issued for people from Cape Leveque to Wallal in the Kimberley, and people have been urged to prepare their homes.

Duty forecaster Darryl Vink said the tropical low sitting to the west of Browse Island could develop into a category 1 or category 2 cyclone before it crossed the coast.

It is expected to make landfall between the Pardoo and Sandfire roadhouses, on a stretch of coastline between Broome and Port Hedland, roughly 1,400 kilometres north of Perth.

Category 2 cyclones can bring damaging winds of between 125 to 164 kilometres per hour, Mr Vink said.

"(There are) destructive winds and quite a bit of rainfall predicted with it as well," he said.

"Falls of at this stage between 50 and 100 millimetres are likely and depending on how much rainfall it brings, possibly over 100, getting into the 150s," he said.

But he said this type of system was not unusual in the region at this time of the year.

Sandfire Roadhouse is in the stretch of northern WA known colloquially as "cyclone alley". ( Krissy Riley (supplied) )

"We generally expect about five cyclones during the season between November and April, two of which we expect to be severe and one which we expect to have a severe coastal crossing," Mr Vink said.

Gales may occur from Beagle Bay to Broome on Wednesday night, and may extend down the Pilbara coast on Thursday.

Strong winds may also hit the community of Port Hedland, home to about 15,000 people, on Thursday.

If the low does develop into a cyclone and cross the coast, it will be the first for the season, and will be called "Hilda".