A tropical cyclone that developed over the Indian Ocean on Thursday night will bring severe weather to parts of Western Australia from Sunday.

Tropical Cyclone Mangga formed to the northwest of the Cocos Keeling Islands on Thursday night. This category one system could cause gale force winds and heavy rain as it passes by the islands on Friday.

Image: Satellite image showing Tropical Cyclone Mangga to the northwest of Australia on Friday. 

From Saturday, Cyclone Mangga will move towards the southeast and approach Western Australia during the weekend. As Mangga moves further away from the equator, the system is likely to transition from a warm-core tropical cyclone into a cold-core extratropical low pressure system.

Despite the technical difference, the low will still be packing quite a punch when it reaches Western Australia on Sunday. Making matters worse, the ex-tropical cyclone will interact with a strong cold front as it passes over Western Australia, leading to widespread dangerous weather across the state.

Image: Forecast accumulated 24 hour rainfall and mean sea level pressure on Sunday night, according to the ECMWF-HRES model.

While strong cold fronts are a common feature in Western Australia in late May, the involvement of an ex-tropical cyclone is rare at this time of year.

The consequence of this rare interaction will be a mix of heavy rain, thunderstorms, damaging to destructive winds and dangerous surf over a broad area of Western Australia on Sunday and Monday. However, the details of where the heaviest rain falls and the strongest winds strike will depend on how the system evolves between now and Sunday.

More accurate information will become available during the next 48 hours as the system approaches Western Australia. Be sure to keep checking the latest forecasts and warnings in the coming days.