Category Archives: Australian Region

Severe Cyclone Lam Reaches Hurricane Intensity Near Wessel Islands

Tropical Cyclone Lam reached hurricane intensity near the northern coast of Australia and was upgraded to Severe Cyclone status.  At 10:00 p.m. EST on Tuesday the center of Severe Cyclone Lam was located at latitude 11.1°S and longitude 137.0°E which put it near the Wessel Islands, about 80 miles north of Nhulunbuy and about 110 miles northeast of Elcho Island, Australia.  Lam was moving toward the west at 8 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and there were gusts to 100 m.p.h.  The minimum surface pressure was 976 mb.

Lam remains over very warm Sea Surface Temperatures and the vertical wind shear is modest.  So, it has the potential to intensify further as long as the center remains over water.  A subtropical ridge is steering Lam westward and that motion is expect to continue for another 8 to 16 hours.  When it reaches the western edge of the ridge, Lam is expected to turn toward the southwest and it could make a landfall west of Elcho Island in 24 to 36 hours.  Lam is strong enough to pose a risk of a significant storm surge and it could also produce locally heavy rainfall and flooding as it moves inland.

 

Tropical Cyclone 13P Forms Northeast of Australia

A second tropical cyclone formed near the coast of Australia when a center of circulation developed in a cluster of thunderstorms northeast of Queensland.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone 13P was located at latitude 16.5°S and longitude 155.9°E which put it 385 miles east of Willis Island and about 800 miles north of Brisbane, Australia.  It was moving toward the south at 7 m.p.h.  The maximum sustained wind speed was 40 m.p.h. and there were gusts to 50 m.p.h.  The minimum surface pressure was 996 mb.

Tropical Cyclone 13P is near the western end of a subtropical ridge and moderately strong northerly winds are blowing over the top of the circulation, especially over the eastern half of it.  As a result, more thunderstorms are forming in the western half of the circulation.  The tropical cyclone is over Sea Surface Temperatures that are warm enough to support intensification.  The upper level northerly winds are enhancing outflow to the south of the circulation and so some intensification is possible.

The subtropical ridge is expected to steer Tropical Cyclone 13P in a generally southwesterly direction, which will move it toward the east coast of Australia.  A landfall near Gladstone could occur in 36 to 48 hours.

 

Cyclone Lam Developed Rapidly Over the Northern Gulf of Carpentaria

A well defined center of circulation developed rapidly on Monday in an area of thunderstorms over the northern Gulf of Carpentaria and the system was classified as Cyclone Lam.  At 10:00 p.m. EST on Monday the center of Lam was located at latitude 11.6°S and longitude 139.4°E which put it about 180 miles east-northeast of Nhulunbuy, Australia and about 260 miles northeast of Alyangula.  Lam was moving toward the west at 5 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were gusts to 80 m.p.h.  The minimum surface pressure was 989 mb.

Lam is an environment that favors intensification.  The Sea Surface Temperatures (SSTs) in the northern Gulf of Carpentaria are near 30°C.  There are light east-southeasterly winds in the upper levels, which are creating some vertical wind shear, but there is well-developed upper level outflow on the western side of the circulation.  The upper level divergence is pumping out mass and the surface pressure is decreasing.  The circulation is tightening up around the core and further intensification is likely.  Given the warm SSTs, rapid intensification is possible if the magnitude of the wind shear remains at a modest level.

A subtropical ridge to the south of Lam is steering it slowly toward the west.  Lam is expected to continue moving westward for another 18 to 24 hours until it reaches the western end of the subtropical ridge.  When Lam reaches the western edge of the ridge, it is expected to move toward the southwest.  The timing of that turn is very important.  If the turn occurs a few hours later than expected, Lam could make landfall in northern Australia near Nhulunbuy.  If Lam turns southwestward sooner, it could remain over the Gulf of Carpentaria longer and make landfall closer to Groote Eylandt.  Lam has the potential to create dangerous storm surges when it makes landfall.  There is also the potential for wind damage, locally heavy rainfall and flooding.