Australia: Tropical Cyclone 18S tracking west-southwestward across the Indian Ocean as of early April 11 /update 2

Event

Tropical Cyclone 18S is tracking west-southwestward across the Indian Ocean early April 11. As of 11:00 AWST, the storm's center of circulation was approximately 443 km (275 miles) north of Broome, Western Australia, Australia. Forecast models indicate that the storm will track southwestwards along the northwestern coast of Western Australia while strengthening into a Category 4 Severe Tropical Cyclone through late April 12. The system is forecast to intensify further into a Category 5 Severe Tropical Cyclone as it turns to track southeast and make landfall over the coast of northwestern Western Australia, northeast of Port Hedland, early April 14. The storm will then track east-southeastward across central Western Australia before dissipating near the border with Northern Territory early April 15. Some uncertainty remains in the track and intensity forecast; changes could occur in the coming days.

As of early April 10, the Australian Bureau of Meteorology (BOM) has issued a cyclone warning from Cape Leveque to Broome, including Broome and a cyclone watch from Broome to Port Hedland, including Port Hedland. Squally thunderstorms with heavy rainfall are forecast over the western Kimberley April 11-12. Heavy rainfall and gales with gusts of up to 90 kph (56 mph) are possible between Cape Leveque and north of Broome early April 12. Abnormally high tides are likely about the Kimberley coast between Kalumburu and Kuri Bay April 11. A flood watch is also in place for the west Kimberley and De Grey rivers and Sandy Desert District catchments from April 11.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a severe health threat.

Advice

Activate contingency plans in areas where officials forecast tropical cyclone conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil-water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center
Australian Bureau of Meteorology