Category Archives: Indian Ocean

Tropical Low Forms North of Australia

A Tropical Low formed north of Australia late on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of the Tropical Low as located at latitude 9.2°S and longitude 130.9°E which put it about 155 miles (250 km) north of Milikapiti, Australia.  It was moving toward the east at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 30 m.p.h. (45 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1004 mb.  The Australian Bureau of Meteorology issued a Watch for the portion of the coast from Milingimbi to Daly River Mouth including Darwin and the Tiwi Islands.

A center of circulation developed in an area of showers and thunderstorms north of Australia late on Wednesday and the Australian Bureau of Meteorology classified the system as a Tropical Low.  The circulation was still organizing.  A short band of showers and thunderstorms wrapped around the southern and western sides of the center.  Other short rainbands were developing in other parts of the circulation.  Storms near the center of circulation were just beginning to generate upper level divergence.

The Tropical Low will move through an environment somewhat favorable for intensification.  It will mover over water where the Sea Surface Temperature is near 30°C.  Westerly winds in the upper levels will cause some vertical wind shear, which will inhibit intensification.  However, the shear is not likely to be strong enough to prevent intensification.  The Tropical Low is likely to strengthen during the next 24 hours.  After that time the intensity will be influenced by how much of the circulation is over Australia.

The Tropical Low is being steered to the east by westerly winds north of Australia.  Those winds are forecast to weaken and the Tropical Low is expected to turn south toward the coast of Australia.  A subtropical ridge over Australia is expected to turn the Tropical Low toward the southwest in a day or so.  On its anticipated track the Tropical Low could be near the northern coast of Australia in 24 to 36 hours.  It could pass near the Cobourg Peninsula, Melville Island and Bathurst Island.  The Tropical Low could also bring gusty winds and heavy rain to the area near Darwin.

Tropical Cyclone 14S Develops East of Madagascar

Tropical Cyclone 14S developed east of Madagascar on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone 14S was located at latitude 14.3°S and longitude 54.6°E which put it about 280 miles (455 km) east-northeast of Ambohitralanana, Madagascar.  It was moving toward the southwest at 6 m.p.h. (10 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 distinct center of circulation developed within a large area of showers and thunderstorms east of Madagascar on Wednesday.  A primary rainband wrapped around the southern, western and northern sides of the center.  Additional bands of showers and thunderstorms formed primarily south and west of the center of circulation.  Storms near the center began to generate upper level divergence which was pumping mass away in all directions.

Tropical Cyclone 14S will be moving through an environment favorable for intensification during the next 24 to 36 hours.  It will move over water where the Sea Surface Temperature is near 29°C.  Tropical Cyclone 14S is under an upper level ridge and the vertical wind shear is not too strong.  Tropical Cyclone 14S will continue to intensify and it could become the equivalent of a hurricane/typhoon before it reaches Madagascar.

Tropical Cyclone 14S is moving near the northwestern portion of a subtropical ridge which is steering the tropical cyclone toward the southwest.  The ridge is forecast to strengthen and a general motion toward the west-southwest is expected.  On its anticipated track Tropical Cyclone 14S could be near the east coast of Madagascar near Ambohitralanana in 24 to 36 hours.  It could be the equivalent of a hurricane/typhoon at that time.  Tropical Cyclone 14S will bring gusty winds and locally heavy rain to parts of Madagascar.  Heavy rain could cause flash floods.

Tropical Cyclone Dumazile Drops Heavy Rain on La Reunion

Tropical Cyclone Dumazile dropped heavy rain on La Reunion on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Cyclone Dumazile was located at latitude 23.3°S and longitude 52.5°E which put it about 260 miles (420 km) southwest of St. Denis, La Reunion.  Dumazile was moving toward the south-southeast at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 949 mb.

Tropical Cyclone Dumazile strengthened into the equivalent of a major hurricane on Monday.  It was a large, powerful tropical cyclone.  There was a small circular eye at the center of the circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several rainbands were revolving around the core of the circulation.  The storms around the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 90 miles (145 km) from the center of circulation.  Winds to tropical storm force extended out about 250 miles (400 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Dumazile was 20.6.  The Hurricane Size Index (HSI) was 30.3 and the Hurricane Wind Intensity Size Index (HWISI) was 50.9.  Those indices indicate that Tropical Cyclone Dumazile would be capable of causing extensive major damage if it made landfall.

Although the core of Tropical Cyclone Dumazile passed between Madagascar and La Reunion, the circulation was so large that rainbands on the eastern side of Dumazile passed over La Reunion.  Those rainbands dropped locally heavy rain and there were unconfirmed reports of flooding in parts of La Reunion.

Tropical Cyclone Dumazile has likely reached its peak intensity.  Dumazile is currently moving over water where the Sea Surface Temperature is near 28°C, but the tropical cyclone will move over colder water when it moves farther south.  An upper level trough near southern Africa is producing northwesterly winds which are blowing toward the top of the circulation.  Those winds are generating vertical wind shear and the shear is forecast to increase during the next several days.  The colder water and increased wind shear are forecast to weaken Tropical Cyclone Dumazile during the next few days.

Tropical Cyclone Dumazile has rounded the western end of a subtropical ridge and it is now moving toward the south-southeast.  A general southeastward motion is forecast for the next two or three days.  On its anticipated track Tropical Cyclone Dumazile should move away from Madagascar and La Reunion.

Tropical Cyclone Dumazile Passes Between Madagascar and La Reunion

Tropical Cyclone Dumazile passed between Madagascar and La Reunion on Sunday night.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Dumazile was located at latitude 20.7°S and longitude 51.1°E which put it about 280 miles (450 km) west of St. Denis, La Reunion.  Dumazile was moving toward the south-southeast at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 961 mb.

Dumazile is a very well organized tropical cyclone. The circulation is symmetrical and there is a small circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring.  Bands of showers and thunderstorms are revolving around the core of the circulation.  Storms in the core are generating strong upper level divergence which is pumping mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out about 230 miles (370 km) from the center.

Tropical Cyclone Dumazile will move through an environment favorable for intensification for about another 24 hours.  Dumazile will move over water where the Sea Surface Temperature is near 29°C.  It will move under an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Dumazile could strengthen into the equivalent of a major hurricane on Monday.  When Dumazile moves farther south in a day or so, it will move over cooler water and into an area where the upper level winds are stronger.  Cooler water and more vertical wind shear will cause Tropical Cyclone Dumazile to weaken when that happens.

Tropical Cyclone Dumazile has rounded the western end of a subtropical ridge and it is now moving toward the south-southeast.  A general southeasterly motion is expected during the next few days.  On its anticipated track Tropical Cyclone Dumazile will move away from Madagascar.  Dumazile is forecast to pass southwest of La Reunion.

Tropical Cyclone Dumazile Brings Wind and Rain to Eastern Madagascar

Tropical Cyclone Dumazile brought wind and rain to eastern Madagascar on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Dumazile was located at latitude 17.0°S and longitude 51.5°E which put it about 90 miles (145 km) east of Ambodifotatra, Madagascar.  Dumazile was moving toward the southwest at 8 m.p.h. (13 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 979 mb.

Tropical Cyclone Dumazile intensified rapidly into the equivalent of a hurricane/typhoon on Saturday.  Satellite images suggested that an eye was forming at the center of circulation.  The developing eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in the ring of storms.  Additional bands of showers and thunderstorms were revolving around the core of the circulation.  Storms in the core were generating strong upper level divergence which was pumping large quantities of mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.

Tropical Cyclone Dumazile will move through an environment very favorable for intensification during the next 24 hours.  Dumazile will move over water where the Sea Surface Temperature is near 30°C.  It will continue to move through a region where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Dumazile is likely to continue to intensify rapidly on Sunday and it could strengthen into the equivalent of a major hurricane.

Tropical Cyclone Dumazile is moving around the western end of a subtropical high pressure system which is steering the tropical cyclone toward the southwest.  Dumazile is likely to move more toward the south as it moves around the western end of the ridge.  On its anticipated track the core of Tropical Cyclone Dumazile is forecast to pass east of the coast of Madagascar.  However, rainbands on the western side of the circulation will bring gusty winds and locally heavy rain to parts of eastern Madagascar.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone 11S Forms East of Northern Madagascar

Tropical Cyclone 11S formed east of the northern tip of Madagascar on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone 11S was located at latitude 13.2°S and longitude 54.3°E which put it about 535 miles (865 km) north of St. Denis, La Reunion.  It was moving toward the southeast at 4 m.p.h. (6 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 996 mb.

A distinct center of circulation finally developed on Friday in an area of thunderstorms that had been stationary northeast of Madagascar.  A primary band of storms wrapped around the northern side of the center of circulation and then storms began to develop near the center.  Additional bands of showers and thunderstorms were revolving around the core of the circulation and the structure of the circulation was organized enough to be classified as a tropical cyclone.  Storms near the center of circulation began to generate upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone 11S will be moving through an environment that is very favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  Tropical Cyclone 11S is located under an upper level ridge and the upper level winds are weak.  There is little vertical wind shear to inhibit intensification.  Tropical Cyclone 11S will intensify during the weekend and it is likely to intensify rapidly at times.  Tropical Cyclone 11S could strengthen into the equivalent of a major hurricane during the next two or three days.

Tropical Cyclone 11S and its precursor have been in an area where the steering winds were weak.  A subtropical ridge located to the east of the tropical cyclone is forecast to strengthen.  The ridge will steer Tropical Cyclone 11S toward the south-southwest.  Early model guidance suggests that the center of the tropical cyclone will move between Madagascar and La Reunion, but there is still uncertainty in the future track of the system.

Stronger Tropical Cyclone Kelvin Makes Landfall in Western Australia

A stronger Tropical Cyclone Kelvin made landfall on the coast of Western Australia near Anna Plains on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Kelvin was located at latitude 19.4°S and longitude 121.9°E which put it about 60 miles (95 km) east-northeast of Sandfire, Australia.  Kelvin was moving toward the east-southeast at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 975 mb.  The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Broome to Wallal Downs and the Warning extends inland to include Telfer.

Tropical Cyclone Kelvin intensified very rapidly before it made landfall on the coast of Western Australia.  Kelvin strengthened in a few hours from a minimal tropical storm to the equivalent of a hurricane/typhoon.  A small circular eye developed at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in the ring of storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Kelvin was a small tropical cyclone.  Winds to tropical storm force only extended out about 60 miles (95 km) from the center of circulation.

Tropical Cyclone Kelvin intensified enough to be capable of causing wind damage, but locally heavy rain is the greater risk.  The small size of Kelvin will limit the area of heavy rain, but there could be enough rain in some areas to create the potential for floods.  The Australian Bureau of Meteorology issued Flood Warnings for the North Kimberly District, the West Kimberly District, and the Sandy Desert.  Flood Watches were issued for the De Grey Rivers and the Salt Lake District Rivers.  Tropical Cyclone Kelvin will weaken as it moves farther inland, but Kelvin will take longer to spin down because it strengthened so much before landfall.

Tropical Cyclone Kelvin Develops Near Western Australia

Tropical Cyclone Kelvin developed near the coast of Western Australia on Saturday.  At 1:00 p.m. EST on Saturday the center of Tropical Cyclone Kelvin was located at latitude 19.2°S and longitude 120.9°E which put it about 60 miles (95 km) north-northeast of Wallal Downs, Australia.  Kelvin was moving toward the east at 4 m.p.h. (6 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 988 mb.  The Australian Bureau of Meteorology issued a Warning for the portion of the coast from Broome to Pardoo Roadhouse and the Warning extended inland to include Telfer.

A Tropical Low meandered near the coast of Western Australia during the past several days.  The Tropical Low moved off the coast and strengthened into Tropical Cyclone Kelvin on Saturday.  The circulation of Kelvin is small.  Winds to tropical storm force only extend out about 60 miles (95 km) from the center of circulation.  Even though it is small, the circulation of Tropical Cyclone Kelvin is well organized.  There is a distinct low level center of circulation.  Thunderstorms are occurring near the center of circulation.  Additional bands of showers and thunderstorms are revolving around the core of Tropical Cyclone Kelvin.  The storms in the core are generating upper level divergence which is pumping away mass.

Tropical Cyclone Kelvin will move through an environment favorable for intensification during the next few hours.  Kelvin will move over water where the Sea Surface Temperature is near 30°C.  It is moving near the southwestern end of an upper level ridge and the upper level winds are weak.  There is little vertical wind shear.  The only factor inhibiting intensification is the proximity to the coast of Western Australia.  Tropical Cyclone Kelvin is likely to intensify until it makes landfall on the coast of Western Australia.  Kelvin should gradually weaken when it moves inland.

The upper level ridge is steering Tropical Cyclone Kelvin slowly toward the east.  That general motion is forecast to continue for several more hours.  Kelvin is likely to move more toward the southeast when it nears the coast.  On its anticipated track Tropical Cyclone Kelvin could make landfall on the coast of Western Australia between Bidyadanga and Wallal Downs within the next 12 hours.  Kelvin will bring gusty winds to the coast, but locally heavy rain and flooding are greater risks.  The Australian Bureau of Meteorology has issued Flood Warnings for the North Kimberly District and the West Kimberly District,  Flood Watches have been issued for the Kimberly and North Pilbara District catchments.  An Initial Flood Warning has been issued for the Sandy Desert.

Tropical Cyclone Cebile Meanders South of Diego Garcia

Tropical Cyclone Cebile has meandered south of Diego Garcia throughout this week.  At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Cebile was located at latitude 16.2°S and longitude 75.8°E which put it about 655 miles (1055 km) south-southeast of Diego Garcia.  Cebile was moving toward the southwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 949 mb.

Although it completed at least one eyewall replacement cycle, Tropical Cyclone Cebile maintains an impressive structure.  There is a circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several rainbands are revolving around the core of the circulation.  The storms in the core are generating upper level divergence which is pumping mass away.  Winds to hurricane/typhoon force extend out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extend out about 250 miles (400 km) from the center.

Tropical Cyclone Cebile remains in an environment favorable for strong tropical cyclones.  It is moving over water where the Sea Surface Temperature is generally near 28°C.  However, Cebile has moved slowly during the past several days and its circulation may have mixed cooler water to the surface in some locations.  The upper level winds are currently weak and there is little vertical wind shear.  Tropical Cyclone Cebile could maintain its intensity for another 24 to 36 hours unless it mixes more cool water to the surface.  An upper level trough approaching from the west will increase the vertical wind shear in a day or two and Cebile could weaken more quickly when that occurs.

Cebile is moving near the western end of a subtropical ridge which has been steering the tropical slowly toward the southwest.  The approaching upper level trough will begin to steer Tropical Cyclone Cebile more toward the southeast in a day or two.  On its anticipated track Tropical Cyclone Cebile is forecast to move farther away from Diego Garcia.

Tropical Cyclone Cebile Intensifies Rapidly Into Equivalent of Major Hurricane

Tropical Cyclone Cebile intensified rapidly on Sunday from a tropical storm to the equivalent of a major hurricane over the South Indian Ocean.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Cebile was located at latitude 14.5°S and longitude 82.5°E which put it about 850 miles (1375 km) southeast of Diego Garcia.  Cebile was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 945 mb.

Tropical Cyclone Cebile intensified very rapidly during the past 24 hours as it moved through a very favorable environment.  The maximum sustained wind speed increased from 50 m.p.h. (80 km/h) to 130 m.p.h. (215 km/h).  The circulation of Tropical Cyclone Cebile is very well organized.  There is a circular eye at the center of circulation.  The eye is surround by a ring of strong thunderstorms and the strongest winds are occurring in the ring of storms.  Rainbands are revolving around the core of the circulation.  Tropical Cyclone Cebile is generating strong upper level divergence which is pumping away mass and allowing the surface pressure to decrease rapidly.

The circulation of Tropical Cyclone Cebile is symmetrical.  Winds to hurricane/typhoon force extend out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extend out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Cebile is 25.1.  The Hurricane Size Index (HSI) is 12.7 and the Hurricane Wind Intensity Size Index (HWISI) is 37.8.

Tropical Cyclone Cebile continues to move through an environment favorable for intensification.  Cebile is moving over water where the Sea Surface Temperature is near 28°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Cebile is likely to intensify further and it could become the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Cebile is moving near the western part of a subtropical ridge which is steering the tropical cyclone toward the southwest.  A general southwesterly motion is expected to continue for the next few days.  On its anticipated track Tropical Cyclone Cebile will remain well south of Diego Garcia.

Elsewhere in the tropics, Tropical Cyclone 08S was moving near the northern end of New Caledonia.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone 08S was located at latitude 18.8°S and longitude 162.1°E which put it about 370 miles (600 km) northwest of Noumea, New Caledonia.  It was moving toward the southeast at 11 m.p.h. (17 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 986 mb.