Tropical Cyclone Sean intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday. At 10:00 a.m. EST on Sunday the center of Tropical Cyclone Sean was located at latitude 20.5°S and longitude 113.9°E which put the center about 125 miles (200 km) north of Exmouth, Australia. Sean was moving toward the west-southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 978 mb.
A Warning was in effect for the portion of the coast from Whim Creek to Ningaloo. The Warning included Karratha, Damoier, Onslow, and Exmouth.
Tropical Cyclone Sea intensified to the equivalent of a hurricane/typhoon near the coast of Western Australia on Sunday. A circular eye with a diameter of 17 miles (28 km) formed at the center of Sean’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Sean. Storms near the core of Sean generated upper level divergence that pumped mass away from the tropical cyclone. The removal of mass caused the surface pressure to decrease.
The circulation around Tropical Cyclone Sean was relatively small. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Sean’s circulation. Winds to tropical storm force extended out 115 miles (185 km) from the center of Tropical Cyclone Sean.
Tropical Cyclone Sean will move through an environment favorable for intensification during the next 24 hours. Sean will move over water where where the Sea Surface Temperatures are near 30°C. It will move under the northern part of an upper level ridge northwest of Australia. The upper level ridge will produce easterly winds are that will blow toward the top of Sean’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification. Tropical Cyclone Sean will intensify during the next 24 hours.
Tropical Cyclone Sean will move around the northwestern part of a high pressure system over Australia. The high pressure system will steer Sean toward the west-southwest during the next 24 hours. On its anticipated track, Tropical Cyclone Sean will move parallel to the coast of Western Australia. The center of Sean is forecast to remain over water.
Bands in the southern side of Tropical Cyclone Sea will bring gusty winds and locally heavy rain to the coast of Western Australia. Heavy rain could cause flash floods in some locations. 3.74 inches (95 mm) of rain fell at the Lombadina Airstrip.
A Flood Watch was in effect for the coastal parts of the Kimberley and the Pilbara Districts. Catchments likely to be affected include the West Kimberley Rivers, the De Grey River, the Pilbara Coastal Rivers, the Fortescue River, the Onslow Coast, and the Lyndon-Minilya Rivers.