Australia: Tropical Cyclone Megan tracking southwestward in the Gulf of Carpentaria off the northeast coast of Northern Territory late March 16 /update 1

Tropical Cyclone Megan is tracking southwestward in the Gulf of Carpentaria off the northeast coast of the Northern Territory late March 16. As of 21:30 ACST, the storm's center of circulation was approximately 757 km (471 miles) east-southeast of Darwin.

Forecast models indicate that the system will strengthen slightly as it tracks generally southwestward toward the southwest coast of the Gulf of Carperntaria through March 17 before making landfall over the Pellew Islands during the morning March 18 and then moving inland over northeastern Northern Territory late March 18-early March 19. After making landfall, the storm is expected to weaken rapidly into a tropical disturbance as it tracks generally west-southwestward into northeastern Northern Territory March 19, Some uncertainty remains in the track and intensity forecast; changes could occur in the coming days.

As of late March 16, the Australian Bureau of Meteorology (BOM) has issued a cyclone warning from Alyangula, NT, to Mornington West, QLD. A cyclone watch is in place from Mornington West to Mornington East. Damaging winds gusting up to 110 kph (68 mph) are occurring over Groote Eylandt March 16 and are expected to continue through early March 17. Winds gusting up to 100 kph (62 mph) are expected to develop between Numbulwar, NT, and Mornington Island, QLD, including Borroloola, early March 17 and over Mornington Island itself from early March 18. Gales may extend inland to Robinson River overnight March 17-18 if the system moves more quickly to the south. Stronger winds gusting up to 125 kph (78 mph) are possible as the system approaches the southwestern Gulf of Carpentaria coast from late March 17. Heavy rainfall is ongoing in eastern parts of the Top End region as of late March 16 and will likely continue through March 17, particularly over island and coastal areas, and will spread into Carperntaria Forecast District in NT and Gulf Country, QLD, March 17. Intense rainfall is possible around Groote Eylandt and coastal parts of the Carpentaria District through at least March 17. Dangerous storm tides are possible in coastal areas between Nathan River, NT, and the NT/QLD border as the cyclone makes landfall; abnormal tides and damaging waves may cause dangerous flooding.

The BOM is also maintaining a severe weather warning for heavy rainfall across eastern coastal parts of the Arnhem Forecast District as of late March 16. Six-hourly rainfall totals of 10-15 cm (4-6 inches) are possible in affected areas before conditions ease overnight March 16-17 as the system moves southward. The heavy downpours may trigger flash flooding in the region and a flood watch has been issued over eastern Top End river catchments. A severe weather warning for abnormally high tides has also been issued for parts of Gulf Country Forecast District, QLD, to the east of the cyclone warning area. Tides up to 1.5 meters (5 feet) above the highest tide of the year are possible in the warning area March 18.

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.