Tropical Cyclone Horacio continued to weaken as it moved over the South Indian Ocean on Wednesday.  At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Horacio was located at latitude 30.9°S and longitude 68.1°E which put the center about 815 miles (1315 km) south-southeast of Port Mathurin, Rodrigues.  Horacio was moving toward the south-southeast at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 981 mb.

An upper level trough that was southeast of Madagascar was producing strong northwesterly winds that were blowing across the top of Tropical Cyclone Horacio.  Those winds were causing strong vertical wind shear.  The strong northwesterly winds were also blowing the top half of Horacio’s circulation to the southeast of the low level center of Horacio.  The strong winds blew the tops off of thunderstorms near the center of Tropical Cyclone Horacio.  Bands near the center and in the northwestern half of Horacio’s circulation consisted primarily of showers and lower clouds.  There will some thunderstorms in the southeastern part of Tropical Cyclone Horacio.

The distribution of wind speeds near the surface in Tropical Cyclone Horacio were still relatively symmetrical.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Horacio’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Tropical Cyclone Horacio.

Tropical Cyclone Horacio will continue to move through an environment that will be unfavorable for intensification during the next 24 hours.  Horacio will move over water where the Sea Surface Temperatures are near 23°C.  The upper level trough that is southeast of Madagascar will continue to cause strong vertical wind shear.  Tropical Cyclone Horacio will continue to weaken during the next 24 hours because of the colder water and the strong vertical wind shear.

Since strong vertical wind shear is blowing the top off of Tropical Cyclone Horacio, Horacio will be steered by weather systems in the lower atmosphere.  Horacio will move around the western end of a high pressure system over the South Indian Ocean.  The high pressure system will steer Horacio toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Horacio will continue to move farther away from Rodrigues.

Tropical Cyclone Horacio weakened on Tuesday as it moved over the South Indian Ocean.  At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Horacio was located at latitude 25.6°S and longitude 65.2°E which put the center about 415 miles (665 km) south-southeast of Port Mathurin, Rodrigues.  Horacio was moving toward the south-southeast at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 960 mb.

Tropical Cyclone Horacio weakened on Tuesday.  An upper level trough that was southeast of Madagascar was producing northwesterly winds that were blowing toward the top of Horacio’s circulation.  Those winds were causing moderate vertical wind shear.  The vertical wind shear caused Tropical Cyclone Horacio to weaken.

The eye was no longer visible on satellite images of Tropical Cyclone Horacio.  Thunderstorms were still occurring in bands revolving around the center of Horacio’s circulation.  However, those thunderstorms were not rising as high into the atmosphere.  Thunderstorms near the center of Horacio generated less upper level divergence.  The removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure increased on Tuesday.

Even though Tropical Cyclone Horacio was weakening, the distribution of wind speeds was still fairly symmetrical.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Horacio’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Horacio.

Tropical Cyclone Horacio will move through an environment that will be unfavorable for intensification during the next 24 hours.  Horacio will move over water where the Sea Surface Temperatures are near 26°C.  The upper level trough that is southeast of Madagascar will continue to cause moderate vertical wind shear.   Tropical Cyclone Horacio will continue to weaken on Wednesday because of the moderate vertical wind shear.

The upper level trough that is southeast of Madagascar will steer Tropical Cyclone Horacio toward the south-southeast during the next 24 hours.  On its anticipated track, Tropical Cyclone Horacio will continue to move farther away from Rodrigues.

Tropical Cyclone Horacio rapidly intensified to the equivalent of a Category 5  hurricane on the Saffir-Simpson Scale as it moved over the South Indian Ocean southeast of Rodrigues on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Cyclone Horacio was located at latitude 21.2°S and longitude 65.0°E which put the center about 145 miles (235 km) southeast of Port Mathurin, Rodrigues.  Horacio was moving toward the southwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) ‘and there were wind gusts to 195 m.p.h. (3150 km/h).  The minimum surface pressure was 920 mb.

Tropical Cyclone Horacio rapidly intensified to the equivalent of a Category 5 hurricane on Sunday night.  A circular eye with a diameter of 20 miles (32 km) was at the center of Tropical Cyclone Horacio.  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 around the center of Horacio’s circulation.  Storms near the center of Horacio generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Tropical Cyclone Horacio increased as Horacio rapidly intensified.   Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of Horacio’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Tropical Cyclone Horacio.

The Hurricane Intensity Index (HII) for Tropical Cyclone Horacio was 35.0.  The Hurricane Size Index (HSI) was 16.7 and the Hurricane Wind Intensity Size Index (HWISI) was 51.7. Tropical Cyclone Horacio was similar in size and intensity to Hurricane Michael when Michael hit Northwest Florida in 2018.

Tropical Cyclone Horacio will move through an environment that will become less favorable for an intense tropical cyclone during the next 24 hours.  Horacio will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the eastern part of an upper level trough that is southeast of Madagascar.  The upper level trough will produce northwesterly winds are that will blow toward the top of Horacio’s circulation.  Those winds will cause the will  vertical wind shear to increase.  Tropical Cyclone Horacio will start to weaken when the vertical wind shear increases.

Tropical Cyclone Horacio will move around the western part of a high pressure system that is over the South Indian Ocean.  The high pressure system will steer Horacio toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Horacio will continue to move farther away from Rodrigues.

Tropical Cyclone Horacio rapidly intensified to the equivalent of a major hurricane as it moved over the South Indian Ocean east of Rodrigues on Sunday night.  At 7:00 a.m. EST on Monday the center of Tropical Cyclone Horacio was located at latitude 19.8°S and longitude 65.8°E which put the center about 160 miles (260 km) east of Port Mathurin, Rodrigues.  Horacio was moving toward the southwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) ‘and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 948 mb.

Tropical Cyclone Horacio rapidly intensified to the equivalent of a major hurricane on Sunday night.  The inner end of a rainband wrapped around the center of Horacio’s circulation.  A circular eye with a diameter of 20 miles (32 km) formed at the center of Tropical Cyclone Horacio.  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 around the center of Horacio’s circulation.  Storms near the center of Horacio generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Tropical Cyclone Horacio was relatively symmetrical.  Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Horacio’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Tropical Cyclone Horacio.

The Hurricane Intensity Index (HII) for Tropical Cyclone Horacio was 23.6.  The Hurricane Size Index (HSI) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 36.8.  Tropical Cyclone Horacio was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Tropical Cyclone Horacio will move through an environment that will be favorable for intensification during the next 24 hours.  Horacio will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the South Indian Ocean.  The upper level winds are weak in the middle of the ridge and there will be little vertical wind shear.  Tropical Cyclone Horacio will intensify during the next 24 hours. Horacio could continue to intensify rapidly during the next few hours.

Tropical Cyclone Horacio will move around the western part of a high pressure system that is over the South Indian Ocean.  The high pressure system will steer Horacio toward the south during the next 24 hours.  On its anticipated track, Tropical Cyclone Horacio will start to move farther away from Rodrigues.