Tag Archives: Tropical Cyclone Ann

Tropical Cyclone Ann Strengthens Over Coral Sea

Tropical Cyclone Ann strengthened over the Coral Sea on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Ann was located at latitude 15.4°S and longitude 153.6°E which put it about 565 miles (910 km) east of Cairns, Australia.  Ann was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 987 mb.

The circulation around Tropical Cyclone Ann exhibited greater organization on Sunday.  There were indications on satellite images that a cloud filled eye might be trying to form at the center of circulation.  A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Ann.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Ann will be moving through an environment that contains factors favorable for intensification and a factor that will inhibit potential intensification.  Ann will move over water where the Sea Surface Temperature is near 28°C.  So, there will be sufficient energy in the upper ocean to support intensification.  Tropical Cyclone Ann will move north of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Ann is surrounded by drier more stable air and the drier air is the factor that will inhibit intensification.  So far, the circulation around Ann has kept the drier air outside the tropical cyclone.  If the drier air remains outside the circulation, then Tropical Cyclone Ann would have a chance to strengthen.  However, if the drier air gets pulled into the circulation, then Ann will weaken.  The higher probability is that Tropical Cyclone Ann could maintain its intensity or weaken slowly during the next day or two depending on what happens to the drier air.

Tropical Cyclone Ann will move north of an area of high pressure, which will steer the tropical cyclone toward the west-northwest.  On its anticipated track Ann will approach the Cape York Peninsula north of Coen in less than 48 hours.  Tropical Cyclone Ann could bring gusty winds and locally heavy rain to northern Queensland.

Tropical Cyclone Ann Forms Over Coral Sea

Tropical Cyclone Ann formed over the Coral Sea on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Ann was located at latitude 16.3°S and longitude 158.7°E which put it about 875 miles (1410 km) east of Cairns, Australia.  Ann was moving toward the west at 5 m.p.h. (8 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 999 mb.

A distinct low level center of circulation became more evident in satellite images of a low pressure system over the eastern Coral Sea on Saturday and the system was designated as Tropical Cyclone Ann.  A rainband wrapped around the southern and western sides of the center of circulation.  A microwave satellite image indicated that the band may have wrapped completely around the center in the middle levels of the circulation.  Storms near the center of circulation began to generate upper level divergence which was pumping mass away from the tropical cyclone.  The circulation around Tropical Cyclone Ann was relatively small.  Winds to tropical storm force extended out about 85 miles (135 km) from the center of circulation in the southern half of Ann.

Tropical Cyclone Ann will move through an environment somewhat favorable for intensification during the next day or two.  Ann will move over water where the Sea Surface Temperature is near 28.5°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will cause some vertical wind shear.  The shear will inhibit intensification, but it is not likely to be strong enough to prevent intensification.  Tropical Cyclone Ann is likely to intensify during the next 24 hours.

The ridge will steer Tropical Cyclone Ann toward the west-northwest during the next two to three days.  On its anticipated track Tropical Cyclone Ann will approach the Cape York Peninsula in northern Queensland in about 72 hours.  Ann could bring gusty winds and locally heavy rain.

Elsewhere around the tropics in the southern hemisphere, Tropical Cyclone Lili was weakening near the coast of East Timor.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Lili was located at latitude 9.1°S and longitude 126.8°E which put it about 120 miles (195 km) east-northeast of Suai, East Timor.  Lili was moving toward the west at 4 m.p.h. (6 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.