A Tropical Low north of Australia strengthened on Thursday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Marcus.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Marcus was located at latitude 10.3°S and longitude 132.6°E which put it about 190 miles (320 km) northeast of Darwin, Australia.  Marcus was moving toward the southeast at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 998 mb.  The Australian Bureau of Meteorology had issued a Warning for the portion of the coast from Maningrida to Daly River Mouth including Darwin and the Tiwi Islands.  A watch was in effect for the portion of the coast from the Daly River Mouth to the Mitchell Plateau.

The circulation inside a Tropical Low north of Australia became better organized on Thursday which led the Australian Bureau of Meteorology to designate the system as Tropical Cyclone Marcus.  A primary band of showers and thunderstorms wrapped around the western and northern sides of the center of circulation.  Other bands of showers and storms were developing in other parts of the circulation.  Storms near the core of Marcus were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Marcus will be moving through an environment mostly favorable for intensification.  Marcus will be moving over water where the Sea Surface Temperature is near 30°C.  It is moving in an area where the upper level winds are weak and there is little vertical wind shear.  The only factor that could inhibit intensification is the proximity of Tropical Cyclone Marcus to the northern coast of Australia.  If the center of Marcus remains north of the coast, then the tropical cyclone is likely to intensify.  If the center moves over land, then a slow weakening would occur.

Tropical Cyclone Marcus is currently moving toward the southeast, but a subtropical ridge over Australia will turn Marcus toward the southwest when it approaches the coast.  On its anticipated track Tropical Cyclone Marcus will approach the northern coast of Australia in about 24 hours.  It is likely to move across the Cobourg Peninsula and over the Van Diemen Gulf.  Tropical Cyclone Marcus could be near Darwin in about 36 hours.  Marcus is forecast to continue southwest over the Timor Sea.

Tropical Cyclone Marcus is likely to bring gusty winds and locally heavy rain to the northernmost portions of the Northern Territory of Australia.  The center will pass close to Darwin and it could bring gusty winds and drop heavy rain over that city.