Narelle moves closer to WA north coast

The latest update from WA's Department of Fire and Emergency services, issued on Saturday morning, says people in Mardie, Onslow, Exmouth and Coral Bay need to prepare for dangerous weather and keep updated with cyclone information.

Cyclone Narelle is estimated to be 445km northwest of Exmouth and 730km north to northwest of Carnarvon.

Narelle is now a category four system, after being categorised as a category five tropical cyclone early this morning. It is expected to weaken to a category three on Monday.

Cyclone Narelle is expected to continue moving south to southwest and pass west of the Northwest Cape during the weekend.

Winds of up to 100km/h could develop in coastal areas between Mardie and Exmouth on Saturday and then extend south to Cape Cuvier.

"Winds are likely to increase in the Exmouth area during Saturday with damaging wind gusts to 125km/h possible overnight on Saturday if the cyclone takes a track closer to the coast," the WA Department of Fire and Emergency Services said in the alert message.

"However, given the consistent movement of Narelle to the south to southwest, movement closer to the coast is now less likely."

Winds were predicted to move south to Denham on Sunday and gales along the west Pilbara coast should ease from the east later in the day.

Thunderstorms in western parts of the Pilbara could be squally with isolated heavy falls and is expected to extend into far northwestern Gascoyne over the weekend, the WA Department of Fire and Emergency Services said.

"Tides along the west Pilbara coast are likely to rise above the normal high tide mark again on Saturday night with flooding of low lying coastal areas possible.

"Higher than normal tides should extend along the west coast later on Saturday and into early next week."

Residents in communities to be affected by the storm are advised to get ready for dangerous weather by preparing their homes, ensuring their family knows what to do and checking an emergency kit is complete.