Tropical Cyclone Garance Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Garance intensified to the equivalent of a hurricane/typhoon north-northwest of La Reunion on Wednesday.  At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Garance was located at latitude 17.8°S and longitude 54.7°E which put the center about 200 miles (325 km) north-northwest of St. Denis, La, Reunion.  Garance was moving toward the east-southeast at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 974 mb.

Tropical Cyclone Garance rapidly intensified to the equivalent of a hurricane/typhoon over the Southwest Indian Ocean north-northwest of La Reunion on Wednesday.  The inner end of a rainband wrapped around the center of Garance’s circulation.  A small circular eye appeared to be forming at the center of Tropical Cyclone Garance.  The developing 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 around the center of Garance’s circulation.  Storms near the center generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Garance was small.  Winds to hurricane/typhoon force extended out 35 miles (55 km) from the center of Garance’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Garance.

The Hurricane Intensity Index (HII) for Tropical Cyclone Garance was 16.5  The Hurricane Size Index (HSI) was 11.2 and the Hurricane Wind Intensity Size Index (HWISI) was 27.7.  Tropical Cyclone Garance was similar in size and intensity to Hurricane Idalia when Idalia hit Florida in 2023.

Tropical Cyclone Garance will move through an environment favorable for intensification during the next 24 hours.  Garance will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the northern side of an upper level low that is southeast of La Reunion.  The upper level low will produce westerly winds that will blow toward the top of Garance’s circulation.  Those winds will some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification. Tropical Cyclone Garance will intensify during the next 24 hours.  Garance is likely to strengthen to the equivalent of a major hurricane.

Tropical Cyclone Garance could get pulled into the eastern side of the larger circulation around Tropical Cyclone Honde, which is over the Mozambique Channel.  The larger circulation around Honde will steer Garance toward the south during the next 24 hours.  On its anticipated track, Garance will approach La Reunion in 24 hours.

Tropical Cyclone Garance is likely to be the equivalent of a major hurricane when it reaches La Reunion.  Garance will be capable of causing major damage on La Reunion.  Tropical Cyclone Garance will also drop heavy rain on La Reunion.  Heavy rain is likely to cause widespread flash flooding.  Garance could cause a storm surge of up to 10 feet (3 meters) along the coast of La Reunion.

Elsewhere, Tropical Cyclone Honde was intensifying over the Mozambique Channel.  At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Honde was located at latitude 24.1°S and longitude 40.2°E which put the center about 255 miles (410 km) west of Toliara, Madagascar. Honde was moving toward the east-southeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 981 mb.