Category Archives: Indian Ocean

Tropical Cyclone Ilsa Intensifies Rapidly Northwest of Australia

Tropical Cyclone Ilsa intensified rapidly over the South Indian Ocean northwest of Australia on Tuesday morning. At 8:00 a.m. EDT on Tuesday the center of Tropical Cyclone Ilsa was located at latitude 15.2°S and longitude 120.5°E which put it about 225 miles (360 km) north-northwest of Broome, Australia. Ilsa was moving toward the southwest at 11 m.p.h. (17 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 984 mb.

A Tropical Cyclone Watch was in effect for the portion of the coast of Western Australia from Beagle Bay to Whim Creek. The Tropical Cyclone Watch included Broome and Port Hedland.

After moving southwest over the South Indian Ocean for three days without strengthening, a low pressure system previous designated as a tropical low intensified rapidly on Tuesday morning. The Australia Bureau of Meteorology designated the system as Tropical Cyclone Ilsa.

The circulation around Tropical Cyclone Isla was organizing quickly. The inner end of a rainband wrapped around the western side of the center of Ilsa’s circulation. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated more upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 100 miles (160 km) from the center of Tropical Cyclone Ilsa.

Tropical Cyclone Ilsa will move through an environment very favorable for intensification during the next 24 hours. Ilsa will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge that extends from northern Australia to the South Indian Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Ilsa is likely to continue to intensify rapidly during the next 24 hours. It will strengthen to the equivalent of a hurricane/typhoon. Ilsa could intensify to the equivalent of a major hurricane within 48 hours.

Tropical Cyclone Ilsa will move around the northwest part of a high pressure system over western Australia. The high pressure system will steer Ilsa toward the southwest during the next 24 hours. Tropical Cyclone Ilsa will move toward the south when it reaches the western end of the ridge on Wednesday. On its anticipated track, Ilsa is likely to make landfall on the coast of Western Australia between Broome and Port Hedland within 60 hours. The center of Tropical Cyclone Isla could make landfall near Wallal Downs. Ilsa is likely to be the equivalent of a major hurricane when it makes landfall.

Tropical Low Forms over Timor Sea

A Tropical Low formed over the Timor Sea northwest of Darwin Australia on Saturday. At 8:00 a.m. EDT on Saturday the center of the Tropical Low was located at latitude 10.3°S and longitude 129.0°E which put it about 105 miles (165 km) northwest of Darwin, Australia. The Tropical Low was moving toward the southwest at 6 m.p.h. (9 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 996 mb.

A Tropical Cyclone Watch was in effect for the portion of the coast of Western Australia from Kalumburu to Cockatoo Island.

A low pressure system over the Timor Sea northwest of Darwin, Australia strengthened on Saturday morning and the Australian Bureau of Meteorology designated the system as a Tropical Low. The distribution of thunderstorms around the Tropical Low was asymmetrical. Most thunderstorms were occurring in bands in the western half of the circulation. Bands in the eastern side of the Tropical Low consisted primarily of showers and lower clouds. The Tropical Low was moving under the northern part of an upper level ridge over northern Australia. The ridge was producing easterly winds that were blowing toward the top of the Tropical Low. Those winds were causing moderate vertical wind shear and the wind shear was causing the asymmetrical distribution of thunderstorms. Storms near the center of circulation generated upper level divergence that pumped mass away to the west of the tropical low.

The Tropical Low will move through an environment that will be somewhat favorable for intensification during the next 36 hours. The Tropical Low will move over water where the Sea Surface Temperatures are near 31˚C. However, the upper level ridge over northern Australia will continue to cause moderate vertical wind shear. The Tropical Low is likely to intensify gradually during the next 36 hours. It could become a named tropical cyclone during that time.

The Tropical Low will move around the northwest part of a high pressure system over western Australia. The high pressure system will steer the Tropical Low toward the southwest during the next 36 hours. On its anticipated track, the Tropical Low will move parallel to the coast of Western Australia during the weekend.

Tropical Cyclone Herman Weakens Southeast of Cocos Islands

Tropical Cyclone Herman weakened over the South Indian Ocean southeast of the Cocos Islands on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Herman was located at latitude 19.9°S and longitude 106.7°E which put it about 865 miles (1395 km) southeast of the Cocos Islands. Herman was moving toward the south-southwest at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 978 mb.

Tropical Cyclone Herman weakened on Saturday. An upper level trough over the South Indian Ocean produced northwesterly winds that blew toward the top of Herman’s circulation. Those winds caused moderate vertical wind shear and the wind shear caused Tropical Cyclone Herman to weaken. An eye was no longer evident on satellite images of Herman. The inner end of a rainband still wrapped around the southern and western sides of the center of Herman’s circulation. The circulation around Tropical Cyclone Herman was small. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Herman. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Tropical Cyclone Herman will move through an environment that will be unfavorable for intensification during the next 36 hours. Herman will move over water where the Sea Surface Temperatures are near 26˚C. However, the upper level trough over the South Indian Ocean will continue to produce northwesterly winds that will blow toward the top of Herman’s circulation. Those winds will continue to cause moderate vertical wind shear and the wind shear will cause Tropical Cyclone Herman to weaken. Since Herman’s circulation is small, the tropical cyclone could weaken rapidly at times.

Tropical Cyclone Herman will move north of high pressure system over the South Indian Ocean. The high pressure system will steer Herman toward the west during the next 36 hours. On its anticipated track, Tropical Cyclone Herman will remain far to the south of the Cocos Islands.

Tropical Cyclone Herman Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Herman strengthened to the equivalent of a major hurricane over the South Indian Ocean northwest of Australia during Thursday night. At 11:00 a.m. EDT on Friday the center of Tropical Cyclone Herman was located at latitude 18.0°S and longitude 106.8°E which put it about 780 miles (1260 km) east-southeast of Cocos Islands. Herman was moving toward the southeast at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 947 mb.

Tropical Cyclone Herman strengthened to the equivalent of a major hurricane over the South Indian Ocean during Thursday night. A small circular eye was present at the center of Herman’s circulation. A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center generated upper level divergence that pumped mass away to the southeast of the tropical cyclone.

The circulation around Tropical Cyclone Herman was small. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Herman. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Herman was 23.6. The Hurricane Size Index (HSI) was 8.6 and the Hurricane Wind Intensity Size Index (HWISI) was 32.2. Tropical Cyclone Herman was similar in size and intensity to Hurricane Dennis when Dennis made landfall in northwest Florida in 2005.

Tropical Cyclone Herman will move through an environment that will become unfavorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. However, an upper level trough will approach Tropical Cyclone Herman from the west. The upper level trough will produce northwesterly winds that will get stronger during the next 24 hours. Those stronger winds will blow toward the top of Herman’s circulation and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken. Since Herman’s circulation is small, the tropical cyclone could weaken rapidly when the wind shear increases.

The upper level trough will steer Tropical Cyclone Herman toward the south-southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move farther away from Cocos Islands. When the stronger vertical wind shear causes Herman to weaken, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the weekend.

Tropical Cyclone Herman Rapidly Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Herman rapidly intensified to the equivalent of a hurricane/typhoon over the South Indian Ocean northwest of Australia on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Cyclone Herman was located at latitude 16.5°S and longitude 106.0°E which put it about 665 miles (1070 km) east-southeast of Cocos Islands. Herman was moving toward the south-southeast at 9 m.p.h. (15 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 959 mb.

Tropical Cyclone Herman rapidly intensified to nearly the equivalent of a major hurricane over the South Indian Ocean on Thursday. A small circular eye was present at the center of Herman’s circulation. A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center generated upper level divergence that pumped mass away to the southeast of the tropical cyclone.

The circulation around Tropical Cyclone Herman was small. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Herman. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Herman was 19.2. The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 28.6. Tropical Cyclone Herman was similar in size and intensity to Hurricane Zeta when Zeta made landfall in Louisiana in 2020.

Tropical Cyclone Herman will move through an environment that will become unfavorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. However, an upper level trough will approach Tropical Cyclone Herman from the west. The upper level trough will produce northwesterly winds that will get stronger during the next 24 hours. Those stronger winds will blow toward the top of Herman’s circulation and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken.

The upper level trough will steer Tropical Cyclone Herman toward the south-southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move farther away from Cocos Islands. When the stronger vertical wind shear causes Herman to weaken, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the weekend.

Tropical Cyclone Herman Strengthens Northwest of Australia

Tropical Cyclone Herman strengthened over the South Indian Ocean northwest of Australia during Wednesday night. At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Herman was located at latitude 15.5°S and longitude 105.1°E which put it about 570 miles (920 km) east-southeast of Cocos Islands. Herman was moving toward the southeast at 10 m.p.h. (16 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 985 mb.

Tropical Cyclone Herman strengthened over the South Indian Ocean northwest of Australia during the past 24 hours. The inner end of a rainband wrapped completely around the center of Herman’s circulation. A small circular eye formed at the center of circulation. A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center generated upper level divergence that pumped mass away to the southeast of the tropical cyclone. Winds to tropical storm force extended out 65 miles (105 km) from the center of Herman’s circulation.

Tropical Cyclone Herman will move through an environment that will become unfavorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. However, an upper level trough will approach Tropical Cyclone Herman from the west. The upper level trough will produce northwesterly winds that will get stronger during the next 24 hours. Those stronger winds will blow toward the top of Herman’s circulation and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken.

The upper level trough will steer Tropical Cyclone Herman toward the southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move farther away from Cocos Islands. When the stronger vertical wind shear causes Herman to weaken, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the end of the week and the weekend.

Tropical Cyclone Herman Forms Northwest of Australia

Tropical Cyclone Herman formed over the South Indian Ocean northwest of Australia on Wednesday morning. At 5:00 a.m. EDT on Wednesday the center of Tropical Cyclone Herman was located at latitude 13.9°S and longitude 101.5°E which put it about 300 miles (480 km) east-southeast of Cocos Islands. Herman was moving toward the southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 997 mb.

An area of low pressure over the South Indian Ocean east-southeast of Cocos Islands strengthened on Wednesday morning and the the Australian Bureau of Meteorology designated the system as Tropical Cyclone Herman. The inner end of a rainband wrapped around the western side of the center of Herman’s circulation. The strongest winds were occurring in the part of the band west of the center. Other bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Herman. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 160 miles (260 km) from the center of Herman’s circulation.

Tropical Cyclone Herman will move through an environment favorable for intensification during the next 24 hours. Herman will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western end of an upper level ridge over the eastern part of the South Indian Ocean. The ridge will produce northerly winds that will blow toward the top of Herman’s circulation. Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification. Tropical Cyclone Herman is likely to strengthen during the next 24 hours. An upper level trough will approach Herman from the west on Thursday. The trough will cause the upper level winds to get stronger and the vertical wind shear will increase. More vertical wind shear will cause Tropical Cyclone Herman to weaken.

Tropical Cyclone Herman will move around the southwestern part of a high pressure system over the eastern South Indian Ocean. The high pressure system will steer Herman toward the southeast during the next 24 hours. On its anticipated track Tropical Cyclone Herman will move away from Cocos Islands. When Herman weakens later this week, it will be steered by the winds closer to the surface. Those winds will steer Tropical Cyclone Herman toward the west during the end of the week and the weekend.

Tropical Cyclone Freddy Drops Heavy Rain on Mozambique

Tropical Cyclone Freddy dropped heavy rain on parts of Mozambique on Sunday. At 8:00 a.m. EDT on Sunday the center of Tropical Cyclone Freddy was located at latitude 17.2°S and longitude 36.3°E which put it about 55 miles (90 km) northwest of Quelimane, Mozambique. Freddy was moving toward the west-northwest at 6 m.p.h. (9 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 996 mb.

Tropical Cyclone Freddy dropped heavy rain on parts of Mozambique and eastern Zimbabwe on Sunday as it moved slowly farther inland. Since Freddy was moving slowly, there were prolonged periods of heavy rain in some locations. The prolonged periods of heavy rain caused a high risk for floods in those locations. Tropical Cyclone Freddy was still producing winds to tropical storm force in the bands in the eastern side of the circulation over the Mozambique Channel.

Tropical Cyclone Freddy will be in an area where the steering winds are weak during the next several days. Freddy’s circulation is forecast to meander over Mozambique and eastern Zimbabwe. Tropical Cyclone Freddy will continue to weaken slowly while the center of circulation is over land. Freddy will continue to drop heavy rain over parts of Mozambique and eastern Zimbabwe for the next 48 hours. Additional flooding is likely to occur in those places that receive prolonged heavy rain.

Tropical Cyclone Freddy Hits Mozambique Again

Tropical Cyclone Freddy hit Mozambique again on Saturday. At 10:00 a.m. EST on Saturday the center of Tropical Cyclone Freddy was located at latitude 17.9°S and longitude 37.2°E which put it about 25 miles (40 km) east of Quelimane, Mozambique. Freddy was moving toward the northwest at 2 m.p.h. (3 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 959 mb.

Tropical Cyclone Freddy intensified before it hit the coast of Mozambique east of Quelimane on Saturday. A circular eye with a diameter of 30 miles (50 km) formed at the center of Freddy’s circulation. A ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Freddy. Storms near the core generated strong upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Freddy increased in size as Freddy intensified. Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Freddy’s circulation. Winds to tropical storm force extended out 140 miles (220 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Freddy was 19.2. The Hurricane Size Index (HSI) was 13.5 and the Hurricane Wind Intensity Size Index (HWISI) was 32.7. Tropical Cyclone Freddy was similar in size and intensity to Hurricane Sally when Sally hit South Alabama in 2020. Tropical Cyclone Freddy was capable of causing regional serious damage.

The steering currents weakened as Tropical Cyclone Freddy approached the coast of central Mozambique. Freddy is forecast to meander near the coast of Mozambique during the next 48 hours. Tropical Cyclone Freddy will begin to weaken when the center of circulation moves completely over land. However, Freddy will cause a prolonged period of strong winds and heavy rain near Quelimane. Heavy rain will cause floods in some locations. Tropical Cyclone Freddy could also cause a storm surge of up to 10 feet (3 meters) along the coast. Widespread electricity outages are likely in the area near Quelimane. There is a chance Freddy could move back over the Mozambique Channel next week.

Tropical Cyclone Freddy Creeps Toward Mozambique

Tropical Cyclone Freddy crept slowly toward the coast of Mozambique on Friday. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Freddy was located at latitude 18.0°S and longitude 38.3°E which put it about 130 miles (210 km) east-southeast of Quelimane, Mozambique. Freddy was moving toward the north-northwest at 5 m.p.h. (8 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.

Tropical Cyclone Freddy crept slowly toward the coast of central Mozambique on Friday. Freddy strengthened gradually as it moved closer to the coast. A small circular eye was at the center of Freddy’s circulation on microwave satellite images. 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 revolved around the core of Tropical Cyclone Freddy. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Freddy was small. Winds to hurricane/typhoon force extended out 15 miles (25 km) from the center of circulation. Winds to tropical storm force extended out 80 miles (130 km) from the center.

Tropical Cyclone Freddy will move through an environment favorable for intensification during the next 24 hours. Freddy will move over water where the Sea Surface Temperatures are near 29˚C. It will be in an area where the upper level winds are weak and there will be little vertical wind shear. Freddy will move into a moister air mass that will be more favorable for intensification. Tropical Cyclone Freddy is likely to intensify gradually during the next 24 hours.

A high pressure system southeast of Madagascar will steer Tropical Cyclone Freddy slowly toward the northwest during the next 24 hours. On its anticipated track Tropical Cyclone Freddy will approach the coast of Mozambique between Quelimane and Pebane. Tropical Cyclone Freddy will bring strong winds and locally heavy rain to the coast of central Mozambique. Heavy rain is very likely to cause flash floods in some locations. Freddy could also produce a storm surge of up to 10 feet (3 meters) along portions of the coast. The currents steering Tropical Cyclone Freddy could weaken even more during the weekend. If the steering currents weaken further, then Freddy could stall near the coast of Mozambique. If Tropical Cyclone Freddy stalls near the coast, then prolonged heavy rain could cause serious floods.