Tropical Low Brings Wind and Rain to Northern Australia

A Tropical Low pressure system brought wind and rain to northern Australia on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of the Tropical Low was located at latitude 12.1°S and 131.5°E which put it about 45 miles (75 km) east-northeast of Darwin, Australia.  The Tropical Low was moving toward the west-southwest at 8 m.p.h. (12 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1000 mb.

The circulation of the Tropical Low is not very well organized.  Many of the thunderstorms are occurring in the outer portions of the circulation.  There are mostly showers, and only a few thunderstorms, near the center of circulation.  There are a few rainbands near the periphery of the circulation, but there is not a well formed core at the center.  The poor organization is preventing the Tropical Low from generating much upper level divergence and as a result the surface pressure has changed little during the past 24 hours.

A significant portion of the circulation of the Tropical Low is over land and that is inhibiting development of the system.  In addition, an upper level ridge to the east of the Tropical Low is producing northerly winds which are blowing across the top of the circulation.  Those winds are causing moderate vertical wind shear which is also inhibiting development.  The Tropical Low is moving toward the west-southwest and the center is forecast to move over the Timor Sea.  If the center of circulation moves over the Timor Sea, it will move over water where the Sea Surface Temperature is near 30°C.  More energy from the water could offset the effects of the vertical wind shear and the Tropical Low could intensify into a tropical cyclone.

A subtropical ridge east of the Tropical Low is steering the system toward the west-southwest and that general motion is expected to continue during the next several days.  On its anticipated track the center of the Tropical Low will move near the northern coast of Australia.  If the center emerges over the Timor Sea, then the system could intensify into a tropical cyclone.  If the center remains over land, then further development will not occur.  In either case the Tropical Low will bring gusty winds and heavy rains to the northern coastal regions of the Northern Territory and Western Australia.