Tropical Cyclone 12S formed north-northeast of Mauritius on Sunday morning. At 5:00 a.m. EST on Sunday the center of Tropical Cyclone 12S was located at latitude 15.1°S and longitude 60.5°E which put it about 430 miles (695 km) north-northeast of Port Louis, Mauritius. The tropical cyclone was moving toward the west-southwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.

Tropical Cyclone 12S formed over the Southwest Indian Ocean early on Sunday morning. The distribution of thunderstorms around Tropical Cyclone 12S was asymmetrical. The strongest thunderstorms were occurring southeast of the center of circulation. Bands in other parts of the tropical cyclone consisted primarily of showers and lower clouds. Storms near the center of circulation began to generate upper level divergence that pumped mass away from the tropical cyclone. The circulation around Tropical Cyclone 12S was small. Winds to tropical storm force extended out 30 miles (50 km) in the southeastern quadrant of the tropical cyclone. The winds in the other parts of Tropical Cyclone 12S were blowing at less than tropical storm force.

Tropical Cyclone 12S will move through an environment somewhat favorable for intensification during the next 24 hours. Tropical Cyclone 12S will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the axis of an upper level ridge over the Southwest Indian Ocean. The upper level winds are weak bear the axis of the ridge and there will be little vertical wind shear. There is drier air to the north of Tropical Cyclone 12S. Drier air could inhibit the formation of thunderstorms in the northern part of the tropical cyclone’s circulation. If drier air inhibits the formation of thunderstorms, then it could prevent intensification of Tropical Cyclone 12S. Since the circulation around Tropical Cyclone 12S is small, changes in the environment could have big effects on the circulation. Tropical Cyclone 12S could get a little stronger during the next 24 hours.

Tropical Cyclone 12S will move north of a subtropical high pressure system over the Southwest Indian Ocean. The high pressure system will steer the tropical cyclone toward the west-southwest during the next several days. On its anticipated track Tropical Cyclone 12S will pass north of Mauritius in 24 hours. The small size of the circulation means that the tropical cyclone should have little effect on Mauritius. Tropical Cyclone 12S could be north of La Reunion in 36 hours. The tropical cyclone could reach northern Madagascar in less than three days.