Tag Archives: Invest 90S

Tropical Low Forms Near Western Australia

A Tropical Low formed near the coast of Western Australia on Friday.  At 4:00 p.m. EST on Friday the center of the Tropical Low was located at latitude 19.0°S and longitude 120.0°E which put the center about 100 miles (160 km) northeast of Port Hedland, Australia.  The tropical low was moving toward the west-southwest at 10 m.p.h. (16 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 995 mb.

A Warning was in effect for the portion of the coast from De Grey to Dampier.  The Warning included Port Hedland and Karratha.

A Watch was in effect for the portion of the coast from Ningaloo to Dampier.  The Watch included Onslow and Exmouth.

A low pressure system over the South Indian Ocean near the coast of Western Australia developed a well defined center of circulation and the Australian Bureau of Meteorology designated the system as a Tropical Low.  A ring of thunderstorms was forming around the center of the Tropical Low.  Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical low.  Bands of showers and thunderstorms were revolving around the center of circulation.

The Tropical Low will move through an environment favorable for the intensification of a tropical cyclone during the next 24 hours.  The Tropical Low will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge northwest of Australia.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  The only factor that will inhibit the intensification of the Tropical Low is the fact that the center of circulation is near the coast of Western Australia.  Much of the southern part of the Tropical Low is over land.  The Tropical Low is likely to intensify to a named tropical cyclone during the next 24 hours.

The Tropical Low will move around the northwestern part of a high pressure system over Australia.  The high pressure system will steer the Tropical Low toward the west-southwest during the next 24 hours.  On its anticipated track, the Tropical Low will move parallel to the coast of Western Australia.  The center of the Tropical Low is forecast to remain over water.

The Tropical Low will bring gusty winds and locally heavy rain to the coast of Western Australia.  Heavy rain is likely to cause flash floods in some locations.

Tropical Depression Forms Northeast of Comoros

A tropical depression formed over the South Indian Ocean northeast of Comoros on Tuesday morning. At 11:00 a.m. EDT on Tuesday the center of a tropical depression was located at latitude 7.7°S and longitude 45.0°E which put it about 250 miles (400 km) northeast of the Comoros. The tropical depression was moving toward the southwest at 11 m.p.h. (17 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 1003 mb.

A low pressure system over the South Indian Ocean northeast of Comoros exhibited more organization on Tuesday morning and Meteo France La Reunion designated the system as a tropical depression. More thunderstorms formed near the center of the tropical depression. Thunderstorms also developed in bands revolving around the center of circulation. Storms near the center began to generate upper level divergence that pumped mass away from the tropical depression.

The tropical depression will move through an environment favorable for intensification during the next 24 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 29°C. It will move under the western end of the axis of an upper level ridge over the South Indian Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. The tropical depression is likely to intensify to the equivalent of a tropical storm during the next 24 hours.

The tropical depression will move around the northern side of a high pressure system over the South Indian Ocean. The high pressure system will steer the tropical depression toward the west-southwest during the next 24 hours. On its anticipated track the tropical depression will move over Comoros on Wednesday. It will bring gusty winds and locally heavy rain to Comoros. Locally heavy rain is likely to cause flash floods in some locations. The tropical depression could approach the coast of Africa near southern Tanzania and northern Mozambique later this week.