Tropical Cyclone Batsirai Moves Toward Madagascar

Tropical Cyclone Batsirai moved toward Madagascar on Thursday night. At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Batsirai was located at latitude 19.5°S and longitude 53.6°E which put it about 120 miles (195 km) northwest of St. Denis, La Reunion. Batsirai was moving toward the west-southwest at 7 m.p.h. (11 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 949 mb.

Tropical Cyclone Batsirai appeared to be nearing the completion of another eyewall replacement cycle on Thursday night. The inner eyewall consisted mostly of a small ring of showers and lower clouds. A much larger eye was evident on satellite images. The outer eyewall consisted of a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the larger eye. Storms near the core of Batsirai’s circulation generated upper level divergence that pumped mass away from the tropical cyclone.

The completion of another eyewall replacement cycle caused the circulation around Tropical Cyclone Batsirai to increase in size again. Winds to hurricane/typhoon force extended out 70 miles (110 km) from the center of Batsirai. Winds to tropical storm force extended out 225 miles (365 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Batsirai was 22.1. The Hurricane Size Index (HSI) was 23.4 and the Hurricane Wind Intensity Size Index (HWISI) was 45.5.

Tropical Cyclone Batsirai will move through an environment capable of supporting a strong tropical cyclone during the next 36 hours. Batsirai will move over water where the Sea Surface Temperatures are near 29˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Batsirai could weaken during the next few hours while it fully completes the eyewall replacement cycle. Batsirai could strengthen again after it completes the eyewall replacement cycle.

Tropical Cyclone Batsirai will move north of a high pressure system over the Southwest Indian Ocean. The high pressure system will steer Batsirai toward the west-southwest during the next 48 hours. On its anticipated track Tropical Cyclone Batsirai could reach the east coast of Madagascar south of Toamasina in 36 hours. Batsirai is likely to be the equivalent of a major hurricane when it reaches Madagascar. Tropical Cyclone Batsirai will bring strong winds and heavy rain to central Madagascar. Heavy rain is likely to cause flash floods especially in regions of steep mountains. Batsirai could also cause a serious storm surge along the coast.