Tropical Cyclone (TC) Mitchell formed over the Indian Ocean more than 630 km west off the WA Pilbara coast. It is this season's first Tropical Cyclone entering Australian waters.
By 8am WST on Saturday morning Mitchell had developed into a Category 1 system and was moving in a south-southwesterly direction at 19 kilometres per hour. As TC Mitchell is expected to move southwards it is expected to intensify into a category 2 system on Saturday evening and Sunday morning while remaining well offshore. By Sunday 8pm WST the system will have moved over cooler waters and will ease into a Category 1 system. As it weakens it will drift further southwest and away from the coast.
At this stage the system is not expected to produce damaging winds in coastal communities, however people in the north west of Western Australia should monitor forecasts and warnings closely.
The indirect effects from this system for the Pilbara communities are an increase in rainfall and wave heights.
The heaviest tropical downpours from Mitchell are expected to stay offshore, however residents in the Pilbara region, and especially the coast, can expect an increase in rainfall from this system on Saturday and Sunday. This brings the risk of flash flooding. Overall 30 to 50 mm of rainfall is expected to accumulate with this system over the next three days.
Combined wave and swell heights are expected to increase to around 2.5 metres on Sunday.
© Weatherzone 2012
08:59 EDT The weather bureau says two category one cyclones are continuing to intensify in north Queensland but at least one is unlikely to affect the coast.