A Tropical Low over the South Indian Ocean was moving toward the coast of Western Australia on Thursday night.  The U.S. Joint Typhoon Warning Center is now designating the Tropical Low as Tropical Cyclone 17S.

At 10:00 p.m. EST on Thursday the center of Tropical Cyclone 17S was located at latitude 13.6°S and longitude 120.2°E which put the center about 355 miles (575 km) north-northwest of Broome, Australia.  Tropical Cyclone 17S was moving toward the southeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 955 mb.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Broome to Kuri Bay.  The Warning included Derby.

A Watch was in effect for the portion of the coast from Bidyadanga to Broome.  A Watch was also in effect for the portion of the coast from Kuri Bay to Mitchell Plateau.

Tropical Cyclone 17S was exhibiting more organization on Thursday evening.  More thunderstorms were occurring in bands in the eastern and western side of the tropical cyclone.  There still were not a lot of thunderstorms near the center of Tropical Cyclone 17S.  The thunderstorms were starting to generate more upper level divergence that was pumping mass away from the tropical cyclone.  The removal of mass was causing the surface pressure to decrease.

The strongest winds were occurring in the northern side of Tropical Cyclone 17S.  Winds to tropical storm force extended out 175 miles (280 km) in the northern side of the tropical cyclone.  The winds in the southern half of Tropical Cyclone 17S were blowing at less than tropical storm force.

Tropical Cyclone 17S will move through an environment favorable for intensification during the next 24 hours.  Tropical Cyclone 17S will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle part of an upper level ridge that is northwest of Australia.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone 17S will Intensify during the next 24 hours.  It could intensify rapidly.

Tropical Cyclone 17S Will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer the tropical cyclone toward the southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone 17S will approach the coast of Western Australia near Cape Leveque in 24 hours.

Tropical Cyclone 17S will bring strong winds and heavy rain to the portion of Western Australia between Broome and Kuri Bay.  Heavy rain could cause flash floods in some locations.

Flood Watches are in effect for the Northwest Kimberley and Western Sandy Desert regions.

Tropical Cyclone 17S could also cause a storm surge of up to 7 feet (2 meters) along the coast of Western Australia.