Tropical Cyclone Anggrek Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Anggrek intensified to the equivalent of a major hurricane over the South Indian Ocean southeast of Diego Garcia on Friday morning. At 4:00 a.m. EST on Friday the center of Tropical Cyclone Anggrek was located at latitude 17.2°S and longitude 86.0°E which put it about 1160 miles (1870 km) southeast of Diego Garcia. Anggrek was moving toward the west-southwest at 13 m.p.h. (21 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 958 mb.

A small circular eye was present at the center of Tropical Cyclone Anggrek. 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 core of Anggrek’ circulation. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone. The removal of large amounts of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Anggrek was symmetrical. Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Anggrek’s circulation. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Anggrek was 22.1. The Hurricane Size Index (HSI) was 12.9 and the Hurricane Wind Intensity Size Index (HWISI) was 35.0.

Tropical Cyclone Anggrek will move through an environment favorable for intensification during the next 24 hours. Anggrek 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 South Indian Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Anggrek is likely to intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. If concentric eyewalls form, then an eyewall replacement cycle could cause Anggrek to weaken temporarily.

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

Elsewhere over the South Indian Ocean, Tropical Cyclone Candice moved farther to the southeast of Mauritius. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Candice was located at latitude 27.1°S and longitude 62.3°E which put it about 565 miles (910 km) southeast of Port Louis, Mauritius. Candice was moving toward the southeast at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (170 km/h). The minimum surface pressure was 988 mb.