Residents of a vast stretch of Western Australia’s coastline are being warned to prepare for two possible tropical cyclones developing offshore.

A cyclone advice alert has been issued by the Department of Fire and Emergency Services for an area spanning from Onslow to Jurien Bay in the state’s Pilbara, Gascoyne and Mid West regions.

Tropical Cyclone Seroja is tracking south from its current position 720 kilometres north-west of Broome and is expected to make landfall as early as Sunday.

A separate tropical low lying well to the south of Christmas Island could develop cyclone intensity in coming days as it tracks east, the Bureau of Meteorology said on Wednesday.

04:44 PM – Cyclone alert issued for Midwest-Gascoyne, Pilbara: https://t.co/ZSEIQCTb4B

— DFES (@dfes_wa) April 7, 2021

It’s possible the two systems will rotate around each other when they get close enough, an interaction known as the Fujiwhara Effect.

“With Tropical Cyclone Seroja approaching from the north-east, the interaction between these two systems is likely to limit development of the tropical low,” the bureau said.

“There is the risk of a period of strong winds and rain associated with this system across the north-west corner of the state over the weekend.”

Authorities are encouraging people living or travelling between Onslow and Jurien Bay to make preparations in coming days.

Residents and holidaymakers between Onslow and Jurian Bay urged to prepare for dangerous weather this weekend from Tropical Cyclone Seroja (Cat1) and Tropical Low 23U forecast to become a Cat 1 Friday, when it would be named TC Odette. More info: https://t.co/DXJaxQfuN2 pic.twitter.com/cffVxKTJQx

— Bureau of Meteorology, Western Australia (@BOM_WA) April 7, 2021

“Cyclones can be incredibly dangerous, bringing heavy rain, flooding, gales and ocean swells,” the DFES said.

“Heavy rainfall can also affect roads, making travel difficult or even unsafe. Some roads may be closed for a period of time.

“People who are travelling or planning to travel through the area, on land or offshore, need to stay informed and make a plan so they know exactly what to do if the situation gets worse.”

-AAP