Multiple tropical threats could take aim at Western Australia this weekend, but AccuWeather meteorologists say they are taking a unique path before reaching land.
Activity in the Timor Sea and eastern Indian Ocean began last weekend when a system emerged and eventually developed into Tropical Cyclone Seroja.
Conditions were just right, with plenty of warm water and light to moderate wind shear, to the northwest of Australia for the tropical low northwest of Seroja to strengthen into Tropical Cyclone Odette on Friday morning, local time, as Seroja continued to gain wind strength.
Both tropical systems are forecast to remain close to one another, with the eye of each cyclone perhaps only 800 km (500 miles) apart.
With two tropical systems so close together, forecasters said a meteorological phenomenon known as the Fujiwhara effect occurred for a time on Friday. The Fujiwhara effect occurs when two tropical systems are close enough together, and strong enough, that they influence the track of the other, resulting in the two storms rotating around each other.
“It looks like Seroja will be the dominant feature, with former Tropical Low Odette rotating in the clockwise fashion around Seroja,” said AccuWeather Senior Meteorologist Adam Douty.
How much the two cyclones interact with each other may be a huge factor in the exact track and strength of these two storms through the weekend. It remains possible that one or both systems can bring impacts to Western Australia.
“The tropical low can brush the west coast of Western Australia on as early as Saturday or Saturday night, with some rain and wind,” Douty said.
Seroja could eventually make a turn to the southeast and move into southwestern parts of Western Australia later Sunday or Monday while maintaining tropical cyclone strength. The final landfall location may be someplace just to the north of Perth.
It is not out of the question that Seroja could strengthen to a Category 3 tropical cyclone on the Australian scale. The storm could pack sustained winds of 158 km/h (98 mph) before approaching southwestern Australia. If Seroja can hold together, it could deliver heavy, flooding rainfall and damaging winds.
When Cyclone Seroja formed over the weekend, tropical moisture inundated portions of Indonesia, causing deadly mudslides and flooding.
Seroja is now far enough removed from eastern Indonesia and East Timor that the threat of additional flooding rainfall has been significantly reduced in those countries.