Tropical Cyclone Hayley formed over the South Indian Ocean northwest of Australia on Sunday. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Hayley was located at latitude 14.4°S and longitude 119.5°E which put the center about 320 miles (520 km) northwest of Broome, Australia. Hayley was moving toward the south at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 993 mb.
A low pressure system over the South Indian Ocean strengthened on Sunday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Hayley.
The Australian Bureau of Meteorology issued a Watch for the portion of the coast of Western Australia from Broome to Cockatoo Island. The Watch includes Derby.
A small low pressure system northwest of Australia strengthened to Tropical Cyclone Hayley. Thunderstorms developed near the center of the low pressure system. Thunderstorms also formed in bands in the western side of Hayley’s circulation. Bands in the eastern side of Tropical Cyclone Hayley consisted primarily of showers and lower clouds. Storms near the center of Hayley generated upper level divergence that pumped mass away to the west of the tropical cyclone. The removal of mass caused the surface pressure to decrease.
The circulation around Tropical Cyclone Hayley was very small. Winds to tropical storm force extended out 35 miles (55 km) from the center of Hayley’s circulation.
Tropical Cyclone Hayley will move through an environment favorable for intensification during the next 24 hours. Hayley will move over water where the Sea Surface Temperatures are near 30°C. It will move under the middle of a small upper level ridge that is northwest of Australia. The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear. Tropical Cyclone Hayley will intensify during the next 24 hours. Hayley could intensify rapidly because its circulation is so small. Tropical Cyclone Hayley is likely to strengthen to the equivalent of a hurricane/typhoon.
Tropical Cyclone Hayley will move around the western end of a high pressure system that is over northern Australia. The high pressure system will steer Hayley toward the southeast during the next 24 hours. On its anticipated track, Tropical Cyclone Hayley will move toward the coast of Western Australia. Hayley is likely to reach the coast east of Broome in less than 48 hours.
Tropical Cyclone Hayley will bring strong winds and locally heavy rain to the coast of Western Australia east of Broome. Heavy rain could cause flash floods in some locations.
Elsewhere over the South Indian Ocean, Tropical Cyclone Gran continued to intensify. At 1:00 p.m. EST on Sunday the center of Tropical Cyclone Grant was located at latitude 13.3°S and longitude 83.5°E which put the center about 900 miles (1450 km) east-southeast of Diego Garcia. Grant was moving toward the west-southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h). The minimum surface pressure was 978 mb.
