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.