Tropical Cyclone Anggrek Spins Far South of Diego Garcia

Tropical Cyclone Anggrek continued to spin over the South Indian Ocean far to the south of Diego Garcia on Monday. At 4:00 p.m. EST on Monday the center of Tropical Cyclone Anggrek was located at latitude 26.9°S and longitude 71.2°E which put it about 1315 miles (2120 km) south of Diego Garcia. Anggrek was moving toward the south at 14 m.p.h. (22 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 944 mb.

Tropical Cyclone Anggrek continued to be small, but powerful. A circular eye with a diameter of 16 miles (26 km) was at the center of Anggrek’s circulation. 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 upper level divergence that pumped mass away from the tropical cyclone.

The small circulation around Tropical Cyclone Anggrek was still symmetrical. Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Anggrek’s circulation. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Anggrek was 22.1. The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 35.9.

Tropical Cyclone Anggrek will move through an environment unfavorable for a strong tropical cyclone during the next 24 hours. Anggrek will move over water where the Sea Surface Temperatures are near 25°C. It will move under the eastern side of an upper level trough that is east of Madagascar. The upper level trough will produce northwesterly winds that will blow toward the top of Anggrek’s circulation. Those winds will cause the vertical wind shear to increase. The combination of cooler water and more vertical wind shear will cause Tropical Cyclone Anggrek to weaken during the next 24 hours. The combination of cooler water and more wind shear will also cause Anggrek to start to make a transition to an extratropical cyclone.

The upper level trough east of Madagascar will steer Tropical Cyclone Anggrek toward the southeast during the next 24 hours. On its anticipated track, Tropical Cyclone Anggrek will move farther away from Diego Garcia.