A pair of cyclones hovering off the Western Australian coast are intensifying and are expected to deliver “rare and dangerous weather’ across the weekend.
Locals and residents along a 1000km stretch of coast have been advised to “prepare now” as tropical cyclones Seroja, which has already caused destruction and deaths to parts of East Timor and Indonesia, and Odette edge closer to land.
Wind gusts of up to 150 km/h could push inland and rain will come “hard and fast,” the Bureau of Meteorology (BOM) has warned.
Seroja could be the most southerly cyclone to make landfall in two decades. That could lead to hectic weather associated with the system as far south as Perth.
“Now is the time to prepare as the impact from these cyclones will be felt in the next 24 to 28 hours, “ said BOM meteorologist Jonathan How on Friday.
Rare Fujiwhara Effect could turbo charge cyclone
Tropical cyclone Seroja, currently a category 1 system, is sitting more than 500kms northwest of Exmouth and 760km northwest of Carnarvon, but is gradually shifting southwest.
Tropical cyclone Odette, also at category 1, is moving south east from a position 940 km northwest of Exmouth and 620 km south east of Christmas Island.
The pair are expected to begin interacting with one another on Saturday in what is knows as the Fujiwhara Effect.
“This rare meteorological phenomenon is taking place with Seroja and Odette engaging in a bit of a rotating dance where cyclones orbit one another,” said Sky News Weather meteorologist Alison Osborne.
Seroja, the stronger of the two, is likely to build up its power at the expense of Odette that could weaken to a tropical low.
Nonetheless, Odette could still pack a punch during its brief life bringing gale force winds and rain to Exmouth on Saturday afternoon.
Tropical cyclone Seroja is expected to cross the coast as a Category 2 system late on Sunday or early Monday.
“Seroja is expected to bring dangerous weather conditions to the west coast during Sunday or Monday … this is a rare event for people on the west coast of Western Australia with potential impacts in the area between Coral Bay and Jurien Bay, including Carnarvon, Denham, Kalbarri and Geraldton,” the Bureau said.
Perth warning: Cyclone could be most southerly in more than two decades
It is almost unheard of for cyclones to make landfall south of Carnarvon with the last such event in 1999. Cyclones need warm water for fuel and the further south these systems go, the cooler the water gets.
“Winds this strong are rarely felt this far south. While most winds will be roughly equivalent to the strongest winds experienced in an intense winter storm in the south west there is a chance that near the coast winds may be slightly stronger,” the BOM stated.
“Heavy rain is expected to fall hard and fast at rates typically only having 10 per cent to 2 per cent chance of occurring in a year.”
The unusual track of Seroja could see Perth impacted.
A pleasant weekend with highs of 30C on Saturday in the WA capital could abruptly end with heavy downpours of up to 20mm on Sunday and Monday with strong winds at times.
Severe weather conditions could also be felt along inland into the Wheatbelt and southern Goldfields during Monday. However, the final track of Seroja is not yet known with the Fujiwhara Effect possibly sending the systems in different directions.
Earlier, tourists holidaying in Western Australia’s north were warned to leave the area as state fierce storms neared.
People between Onslow and Perth are urged to prepare for tough weather conditions, with dangerous surf and a storm surge making the ocean treacherous, the BOM warned.