Timor Sea: Tropical low tracking southwards towards northern Australia as of Dec. 22

Event

A tropical low has formed in the Timor Sea and is tracking southward towards the coast of northern Australia as of Dec. 22. As of 15:30 ACST, the storm's center of circulation was approximately 198 km (123 miles) south of Darwin.

Forecast models indicate that storm will strengthen into a Category 1 Tropical Cyclone, upon which it will be named Cyclone Ellie, as it tracks south-southeastward over the Joseph Bonaparte Gulf overnight Dec. 23-24 before making landfall close to Wadeye in northwestern Northern Territory, close to the Western Australia border, early Dec. 23. The system is expected to maintain Category 1 Tropical Cyclone strength as it continues to track south-southwestwards into northwestern Northern Territory Dec. 23-early Dec. 24, before weakening into a tropical depression as it turns to tracks southwards then south-southwestwards close to the Western Australia border Dec. 24-26. The system is forecast to take a turn south-southeastward before dissipating over southwestern Northern Territory Dec. 27. The storm's track and intensity forecast remain somewhat uncertain, and changes may occur over the coming days.

As of Dec. 22, the Australian Bureau of Meteorology (BoM) has issued a cyclone warning along the coast from Dundee in the Northern Territory to Kalumburu in Western Australia. The warning area includes Wadeye, Kununurra, and Wyndham, but not Kalumburu. Gales producing wind gusts up to 90 kph (56 mph) are possible in parts of the warning area from late Dec. 22. Heavy rainfall is expected to develop from late Dec. 22 over Daly District and will extend into Gregory and east Kimberley districts Dec. 23. Thunderstorms are also possible in the area Dec. 22-23. Higher than normal tides are expected in the warning area, which could trigger coastal flooding.

Further impacts from the warning area are expected across a wider area due to unstable weather conditions associated with the storm. The BoM has issued a severe weather warning for damaging winds and heavy rainfall for Tiwi Island and parts of Daly, Arnhem, and Gregory districts and flood watches have been issued for river catchments across much of the Northern Territory and parts of eastern Western Australia. Marine wind warnings are also in place for coastal areas of northwestern Northern Territory and northeastern Western Australia.

Officials will likely issue new alerts or update/rescind existing advisories as the storm progresses.

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

The inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Raw sewage and other hazardous materials mixed with floodwaters pose a serious health threat.

Advice

Activate contingency plans in areas where officials forecast adverse weather 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. 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