NASA's Tropical Rainfall Measuring Mission satellite spotted light to moderate rainfall in the system as continues tracking southwest and bringing rains and winds to the northern coast of Western Australia this weekend. System 91S was located in the Timor Sea, west-southwest of Darwin, Australia and was moving in a west-southwesterly direction. System 91S is forecast to continue traveling in that direction and its center is expected to remain at sea over the next several days as it heads toward the Southern Indian Ocean.
As it continues to track along coastal areas of the Northern Territory and Western Australia, cyclone warnings are in effect. A Cyclone Warning is in effect for Western Australian coastal and island areas from Kuri Bay to the Western Australia/Northern Territory border, including Kalumburu and Wyndham. In addition, a cyclone watch is in effect from Kuri Bay to Cape Leveque, not including Derby. The TRMM satellite, operated by both NASA and the Japanese Space Agency, passed over the system at 1451 UTC on April 1. The U.S. Navy and Naval Research Laboratory's Monterey Marine Meteorology Division, Calif. overlaid TRMM rainfall rate imagery on top of Japan's METSAT-2 infrared imagery to provide a complete picture of the low pressure areas cloud extent and rainfall rates. TRMM's precipitation radar instrument measured rainfall rates close to 1 inch (25 mm) per hour.