Tropical Cyclone Bianca strengthened to the equivalent of a hurricane/typhoon over the South Indian Ocean on Sunday night.  At 4:00 a.m. EST on Monday the center of Tropical Cyclone Bianca was located at latitude 19.3°S and longitude 103.3°E which put the center about 645 miles (1040 km) southeast of the Cocos Islands.  Bianca was moving toward the southwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 985 mb.

Tropical Cyclone Bianca rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean southeast of the Cocos Islands during Sunday night.  The inner end of a rainband wrapped around the center of Bianca’s circulation.  A circular eye formed at the center of Tropical Cyclone Bianca.  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 revolved around the center of Bianca’s circulation.  Storms near the center of Bianca 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 Bianca was small.  Winds to hurricane/typhoon force extended out 20 miles (3o km) from the center of Bianca’s circulation.  Winds to tropical storm force extended out 75 miles (120 km) from the center of Tropical Cyclone Bianca.

Tropical Cyclone Bianca will move through an environment favorable for intensification during the next 24 hours.  Bianca will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the middle of an upper level ridge over the South Indian Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Bianca is likely to continue to intensify during the next 24 hours.

Tropical Cyclone Bianca will move around the northwestern part of a high pressure system over the South Indian Ocean.  The high pressure system will steer Bianca toward the southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Bianca will remain far to the southeast of the Cocos Islands.