Tropical Cyclone Freddy Rapidly Intensifies to near Threshold for Cat. 5 Hurricane

Tropical Cyclone Freddy rapidly intensified to near the threshold for a Category 5 hurricane on the Saffir-Simpson Scale on Wednesday morning. At 10:00 a.m. EST on Wednesday the center of Tropical Cyclone Freddy was located at latitude 15.0°S and longitude 84.2°E which put it about 1000 miles (1615 km) southeast of Diego Garcia. Freddy was moving toward the west at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h). The minimum surface pressure was 920 mb.

Tropical Cyclone Freddy rapidly intensified over the South Indian Ocean during Tuesday night. Freddy was near the threshold for a Category 5 hurricane on the Saffir-Simpson Scale on Wednesday morning. A circular eye with a diameter of 15 miles (24 km) was at the center of Tropical Cyclone Freddy. The eye was surrounded by 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 core of Freddy’s circulation. Storms near the core generated strong upper level divergence that pumped mass away from the tropical cyclone in all directions.

Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Tropical Cyclone Freddy. Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation. The Hurricane Intensity Index (HII) for Freddy was 33.3. The Hurricane Size Index (HSI) was 12.4 and the Hurricane Wind Intensity Size Index (HWISI) was 45.7.

Tropical Cyclone Freddy will move through an environment that will be favorable for a strong tropical cyclone during the next 24 hours. Freddy will move over over water where the Sea Surface Temperatures are near 28˚C. An upper level ridge over the South Indian Ocean will produce easterly winds that will blow toward the top of Freddy’s circulation. The winds in the lower levels of the atmosphere will also blow from the east. So, there will be little vertical wind shear. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could forms. That would start an eyewall replacement cycle that would cause Tropical Cyclone Freddy to weaken temporarily.

Tropical Cyclone Freddy will move around the northern part of a high pressure system over the South Indian Ocean. The high pressure system will steer Freddy toward the west during the next few days. On its anticipated track, Tropical Cyclone Freddy will move south of Diego Garcia in three days. Freddy could eventually threaten Mauritius, La Reunion and Madagascar in a few days.

Elsewhere over the South Indian Ocean, Tropical Cyclone Dingani continued to make a transition to an extratropical cyclone. At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Dingani was located at latitude 27.2°S and longitude 69.2°E which put it about 635 miles (1025 km) southeast of Rodrigues. Dingani was moving toward the southwest at 21 m.p.h. (33 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 991 mb.