Tropical Cyclone Dudzai intensified back to the equivalent of a Category 4 hurricane as it moved over the South Indian south of Diego Garcia on Thursday. At 4:00 p.m. EST on Thursday the center of the Tropical Cyclone Dudzai was located at latitude 16.9°S and longitude 72.4°E which put the center about 675 miles (1090 km) south of Diego Garcia. Dudzai was moving toward the west at 11 m.p.h. (17 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h). The minimum surface pressure was 942 mb.
Tropical Cyclone Dudzai rapidly intensified back to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Thursday. Dudzai started to intensify rapidly after it moved west of cooler water that its winds had mixed to the surface of the ocean earlier this week. Tropical Cyclone Dudzai was able to extract more energy from the South Indian Ocean, which cause it to intensify rapidly.
A small circular eye was visible again on satellite images at the center of Tropical Cyclone Dudzai. 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 were revolving round the core of Dudzai’s circulation. Storms near the core of Dudzai generated more upper level divergence that pumped more mass away from the tropical cyclone. The removal of more mass caused the surface pressure to decrease rapidly.
The size of the circulation around Tropical Cyclone Dudzai increased on Thursday. Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Dudzai’s circulation. Winds to tropical storm force extended out 150 miles (240 km) in the southern half of Tropical Cyclone Dudzai. Winds to tropical storm force extended out 80 miles (130 km) in the northern side of Dudzai’s circulation.
The Hurricane Intensity Index (HII) for Tropical Cyclone Dudzai was 28.3. The Hurricane Size Index (HSI) was 13.0 and the Hurricane Wind Intensity Size Index (HWISI) was 41.3. Tropical Cyclone Dudzai was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.
Tropical Cyclone Duzai will move through an environment favorable for a strong tropical cyclone during the next 24 hours. Dudzai will move over water where the Sea Surface Temperatures are near 28°C. It will move under the northern part of an upper level trough that is over the South Indian Ocean. The upper level trough will produce westerly winds that will blow toward the top of Dudzai’s circulation. Those winds will cause some vertical wind shear. The vertical wind shear will inhibit intensification. Tropical Cyclone Dudzai is likely to start to weaken on Friday because of the vertical wind shear.
Tropical Cyclone Dudzai will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Dudzai toward the west on during the next 24 hours. On its anticipated track, Tropical Cyclone Dudzai will remain far to the south of Diego Garcia. Dudzai could approach Rodrigues during the weekend.