Tropical Cyclone 22s (Ilsa) Intensifies Rapidly
Tropical Cyclone 22s (Ilsa), located approximately 720 nautical miles east-southeast of Cocos Island, has tracked southwestward at 12 knots over the past six hours. Maximum significant wave height is 18 feet.
It has passed between Jakarta, Indonesia, and Learmonth, on Australia’s North West Cape (the peninsula on the bottom right).
Animated water vapor imagery shows that the convection around the low level circulation center has further deepened and consolidated.
Upper level analysis indicates the system has tracked closer to the subtropical ridge axis and consequently, vertical wind shear (VWS) has weakened, contributing to the rapid intensification over the past 12 hours.
TC 22S will continue to track west-southwest along the northern periphery of the subtropical ridge and further intensify up to TAU 36. After that time, the system will slightly weaken with increased VWS as the ridge to the South builds.