A potential threat posed by Tropical Cyclone Seroja prompted the issuance of a Watch for the coast of Western Australia. At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Seroja was located at latitude 19.2°S and longitude 109.8°E which put it about 315 miles (505 km) northwest of Exmouth, Australia. Seroja was moving toward the southwest at 12 m.p.h. (19 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 994 mb.
A Tropical Cyclone Watch was issued for the portion of the coast of Western Australia from Coral Bay to Lancelin. The Watch included Carnarvon, Denham, Kalbarri and Geraldton.
More thunderstorms developed in bands revolving around the center of Tropical Cyclone Seroja on Thursday night. The distribution of thunderstorms was more symmetrical, which indicated that the vertical wind shear was decreasing. Thunderstorms near the center of circulation generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 115 miles (185 km) from the center of Seroja.
Tropical Cyclone Seroja will move through an environment favorable for intensification during the next 36 hours. Seroja will move over water where the Sea Surface Temperatures will be near 30°C. It will move under the axis of an upper level ridge centered northwest of Australia during the next 24 hours. The upper level winds are weaker near the axis of the ridge and the wind shear will decrease. Tropical Cyclone Seroja could strengthen into the equivalent of a hurricane/typhoon during the next 24 hours. Seroja could strengthen more rapidly if the inner end of a rainband wraps around the center and an inner core forms.
Tropical Cyclone Seroja will move around the northwestern part of a high pressure system over Australia during the next day or so. The high will steer Seroja toward the southwest during the next 24 hours. An upper level trough over the South Indian Ocean will approach Tropical Cyclone Seroja from the west during the weekend. The trough will turn Seroja toward the southeast. On its anticipated track Tropical Cyclone Seroja will make landfall on the coast of Western Australia between Denham and Lancelin in 60 hours.
Elsewhere over the South Indian Ocean, Tropical Cyclone Odette was interacting with the northwest side of Tropical Cyclone Seroja. At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Odette was located at latitude 14.5°S and longitude 108.2°E which put it about 675 miles (1090 km) northwest of Exmouth, Australia. Odette was moving toward the east at 9 m.p.h. (15 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 988 mb. Even though the wind speeds are stronger in Tropical Cyclone Odette than they are in Tropical Cyclone Seroja, the circulation around Seroja is larger. The circulation of Odette is forecast to absorbed by the larger circulation of Seroja. In addition, upper level divergence from Seroja will cause vertical wind shear over Odette, which will also cause the circulation around Odette to weaken.