Tropical Cyclone Marian strengthened south of Cocos Island on Friday. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Marian was located at latitude 14.9°S and longitude 96.4°E which put it about 190 miles (310 km) south of Cocos Island. Marian was moving toward the west at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 979 mb.
The circulation around an area of low pressure over the South Indian Ocean south of Cocos Island exhibited much more organization on Friday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Marian. Marian organized quickly during the past few hours. An eye was beginning to appear at the center of Marian on infrared satellite images. The inner end of a rainband was wrapping around the eye and the strongest winds were occurring in the developing eyewall. Thunderstorms near the center of Marian generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 200 miles (320 km) in the southern half of Tropical Cyclone Marian. Winds to tropical storm force extended out 120 miles (195 km) in the northern half of Marian.
Tropical Cyclone Marian will move through an environment favorable for intensification during the next 36 hours. Marian will move over water where the Sea Surface Temperatures will be near 29°C. It will move under the northern portion of an upper level ridge. The ridge will produce easterly winds which will blow toward the top of the circulation. However, the winds speeds will be similar at different levels in the atmosphere and there will not be a lot of vertical wind shear. Tropical Cyclone Marian will intensify into the equivalent of a hurricane/typhoon during the next 24 hours.
Tropical Cyclone Marian will move around the northwestern part of a subtropical high pressure system. The high will steer Marian toward the west-southwest during the next several days. On its anticipated track Tropical Cyclone Marian will move farther away from Cocos Island.