Tag Archives: South Indian Ocean

Tropical Cyclone Flamboyan Forms East of Diego Garcia

Tropical Cyclone Flamboyan formed over the South Indian Ocean east of Diego Garcia on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Garcia was located at latitude 10.6°S and longitude 89.2°E which put it about 1190 miles (1925 km) east-southeast of Diego Garcia.  Flamboyan was moving toward the west-southwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 995 mb.

A distinct low level center of circulation developed inside a large areas of showers and thunderstorms east of Diego Garcia on Saturday and the system was designated as Tropical Cyclone Flamboyan.  The circulation of Tropical Cyclone Flamboyan organized steadily during the day.  Several bands of showers and thunderstorms were revolving the core of the circulation.  Storms near the core were generating upper level divergence which was pumping away mass from the tropical cyclone in all directions.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Flamboyan will be moving through an environment favorable for intensification during the next day or two.  Flamboyan will move over water where the Sea Surface Temperature is near 28°C.  It is located under an upper level ridge and the upper level winds are weak.  Flamboyan will move through an area where there is little vertical wind shear.  Warm water and little shear will allow Tropical Cyclone Flamboyan to intensify and it could strengthen into the equivalent of a hurricane/typhoon.

Tropical Cyclone Flamboyan is moving around the western end of a subtropical ridge, which is steering the tropical cyclone toward the west-southwest.  Flamboyan will turn more toward the south when it rounds the western end of the ridge.  On its anticipated track Tropical Cyclone Flamboyan will move farther away from Cocos Island and it will pass well southeast of Diego Garcia.

Tropical Cyclone Marcus Strengthens to Equivalent of Category 5 Hurricane Northwest of Australia

Tropical Cyclone Marcus strengthened into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale as it churned northwest of Australia on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Marcus was located at latitude 15.8°S and longitude 108.0°E which put it about 600 miles (960 km) northwest of Learmonth, Australia.  Marcus was moving toward the west-southwest at 14 m.p.h. (22 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. (315 km/h).  The minimum surface pressure was 918 mb.

After completing an eyewall replacement cyclone on Tuesday, Tropical Cyclone Marcus began to intensify quickly again on Wednesday.  Marcus exhibited a circular, symmetrical circulation.  There was a tiny circular eye at the center of circulation.  The strongest winds were occurring in a ring of thunderstorms that surrounded the small inner eye.  Recent satellite images suggested that another eyewall replacement cycle may be beginning.  A larger, outer eyewall appeared to have encircled the small inner eye.  Bands of showers and thunderstorms were revolving around the concentric eyewalls.  Storms in the core of Marcus were generating very well developed upper level divergence which was pumping mass away in all directions from the tropical cyclone.

As frequently happens during eyewall replacement cycles, Tropical Cyclone Marcus increased in size after Tuesday’s eyewall replacement cycle was completed.  Winds to hurricane/typhoon force extended out about 50 miles (85 km) from the center of circulation.  Winds to tropical storm force extended out 180 miles (290 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Marcus was 35.0.  The Hurricane Size Index (HSI) was 18.7 and the Hurricane Wind Intensity Size Index (HWISI) was 53.7.

Tropical Cyclone Marcus is in an environment that is very favorable for strong tropical cyclones.  Marcus is moving over water where the Sea Surface Temperature is near 30°C.  It is moving through an area where the upper level winds are weak and there is little vertical wind shear.  Although Tropical Cyclone Marcus is in a very favorable environment, another eyewall replacement cycle would cause it to weaken.  The wind would begin to converge into the outer eyewall, which would cause the storms in the inner eyewall to weaken.  The wind speeds would decrease as the inner eyewall weakens.  Then the strongest winds would be found in the outer eyewall and the circulation would increase in size.

Tropical Cyclone Marcus is nearing the western end of a subtropical ridge over Australia.  The ridge is steering Marcus toward the west-southwest, but the tropical cyclone will turn more toward the south when it reaches the end of the ridge.  Tropical Cyclone Marcus will make a gradual turn toward the southeast during the next several days.  On its anticipated track Tropical Cyclone Marcus will remain west of Western Australia during the next 36 to 48 hours.

Tropical Cyclone Marcus Strengthens Into Equivalent of Major Hurricane

Tropical Cyclone Marcus strengthened into the equivalent of a major hurricane on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Marcus was located at latitude 15.0°S and longitude 117.7°E which put it about 340 miles (550 km) north of Port Hedland, Australia.  Marcus was moving toward the west at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 955 mb.

The circulation of Tropical Cyclone Marcus was symmetrical and very well organized.  A very small circular eye was at the center of 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 core of the circulation.  Storms in 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 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 190 miles (305 km) from the center.

Tropical Storm Marcus will continue to move through an environment very favorable for strong tropical cyclones during the next two days.  Marcus will move over water where the Sea Surface Temperature is near 30°C.  It is moving under an area where the upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Marcus is likely to intensify and it could reach the equivalent of a Category 5 hurricane.  If a rainband wraps around the core of the circulation, then a second eyewall could form.  That would initiate an eyewall replacement cycle, which would cause Marcus to weaken at least temporarily.

Tropical Cyclone Marcus is moving around the western end of a subtropical ridge, which is steering Marcus toward the west.  A general motion toward the west is expected to occur for anther 24 to 48 hours.  Marcus will reach the western end of the ridge in about two days, and then the tropical cyclone will turn toward the south.  On its anticipated track Tropical Cyclone Marcus will stay north of the coast of Western Australia for the next few days.

Tropical Cyclone Marcus Strengthens Rapidly North of Australia

Tropical Cyclone Marcus moved back over the South Indian Ocean on Sunday and it strengthened rapidly north of Australia.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Marcus was located at latitude 15.0°S and longitude 122.8°E which put it about 215 miles (345 km) north-northeast of Broome, Australia.  Marcus was moving toward the west at 11 m.p.h. (17 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 987 mb.

Tropical Cyclone Marcus weakened when it moved over the northernmost part of Western Australia, but it began to strengthen quickly after the core moved back over water.  An eye rapidly reformed at the center of circulation.  A ring of strong thunderstorms redeveloped around the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  The circulation of Tropical Cyclone Marcus was relatively compact.  Winds to tropical storm force extended out about 80 miles (130 km) from the center of circulation.

Tropical Cyclone Marcus will be moving through an environment very favorable for intensification during the next two days.  Marcus will move over water where the Sea Surface Temperature is near 30°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Marcus is likely to continue to intensify rapidly and it could become the equivalent of a major hurricane in 24 to 36 hours.

Tropical Cyclone Marcus is moving around the northern side of a subtropical ridge over Australia, which is steering Marcus toward the west.  A general motion toward the west is forecast to continue for several more days.  Tropical Cyclone Marcus will reach the western end of the ridge in two or three days.  Marcus will turn toward the south at that time.  On its anticipated track Tropical Cyclone Marcus will move farther away from the coast of Western Australia during the next two days.

Tropical Cyclone Marcus Makes Landfall on North Coast of Australia

Tropical Cyclone Marcus made landfall on the northern coast of Western Australia east of Kalumburu on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Cyclone Marcus was located at latitude 14.2°S and longitude 127.7°E which put it about 70 miles (115 km) east of Kalumburu, Australia.  Marcus was moving toward the west-southwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 85 m.p.h. (140 km/h).  The minimum surface pressure was 984 mb.  The Australian Bureau of Meteorology issued a Warning for the portion of the coast between Wyndham and Beagle Bay not including Wyndham or Derby.

Tropical Cyclone Marcus strengthened as it moved over the Timor Sea on Saturday.  There was a small circular eye at the center of circulation.  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 the circulation.  Storms in the core were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Marcus will weaken on Sunday while the core of the circulation moves over the extreme northern part of Western Australia.  Marcus is likely to strengthen when the center moves west of Kuri Bay and back out over water.  The Sea Surface Temperature of the water west of Kuri Bay is around 30°C.  The upper level winds will be weak and there will be little vertical wind shear.  Marcus will likely intensify into the equivalent of a hurricane/typhoon after the center of circulation moves back over water.

Tropical Cyclone Marcus is moving north of a subtropical ridge over Australia.  The ridge is steering Marcus to the west-southwest and that general motion is expected to continue for several more days.  On its anticipated track Tropical Cyclone Marcus will move over the Mitchell Plateau toward Kuri Bay.  Marcus will move away from the north coast of Western Australia when it moves west of Kuri Bay.

Tropical Cyclone Eliakim Stalls and Drops Heavy Rain on Madagascar

Tropical Cyclone Eliakim stalled over Madagascar on Friday night and it was dropping heavy rain on northern Madagascar.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Eliakim was located at latitude 16.0°S and longitude 49.5°E which put it about 300 miles (480 km) northeast of Antananarivo, Madagascar.  Eliakim was stationary.  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The strongest winds were occurring in rainbands over the Indian Ocean.  The minimum surface pressure was 994 mb.

The steering currents weakened on Friday as Tropical Cyclone Eliakim was rounding the western end of a subtropical ridge over the Indian Ocean.  Eliakim has moved little during the past 12 hours.  The center of circulation was over land close to the east coast of Madagascar near Mananara.  Since Tropical Cyclone Eliakim was nearly stationary, bands of showers and thunderstorms were dropping heavy rain on parts of Madagascar.  The heavy rain was creating the potential for serious flooding, especially in areas of steep terrain.

The subtropical ridge is forecast to strengthen during the weekend.  When the ridge strengthens the steering currents will start to move Tropical Cyclone Eliakim toward the south.  On its anticipated track Eliakim is forecast to move almost straight southward near the east coast of Madagascar.  Tropical Cyclone Eliakim will drop heavy rain on parts of Madagascar for several more days and it could cause very serious flooding in some places.

Tropical Cyclone Eliakim Strengthens East of Madagascar

Tropical Cyclone Eliakim strengthened east of Madagascar on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Eliakim was located at latitude 15.3°N and longitude 52.6°E which put it about 140 miles (225 km) east of Ambohitralanana, Madagascar.  Eliakim was moving toward the west-southwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 60 m.p.h. (96 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 989 mb.

The circulation of Tropical Cyclone Eliakim became better organized on Thursday morning.  A partial eyewall surrounded the northern and eastern sides of the center of circulation.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Eliakim.  Storms near the core were generating well developed upper level divergence which was pumping mass away in all directions from the tropical cyclone.  Winds to tropical storm force extended out about 75 miles (120 km) from the center of circulation.

Tropical Cyclone Eliakim will move through an environment favorable for intensification during the next 18 to 24 hours.  Eliakim will move over water where the Sea Surface Temperature is near 28°C.  It is under an upper level ridge and the upper level winds are weak.  So, there is little vertical wind shear.  Tropical Cyclone Eliakim will continue to intensify until it reaches the coast of Madagascar in a day or so.  Eliakim is likely to be the equivalent of a hurricane/typhoon when it reaches Madagascar.

Tropical Cyclone Eliakim is moving around the western portion of a subtropical ridge which is steering the tropical cyclone toward the west-southwest.  A general motion toward the west-southwest is expected to continue for another 24 to 36 hours.  On its anticipated track the center of Tropical Cyclone Eliakim could be near the coast of Madagascar south of Ambohitralanana in 18 to 24 hours.  Eliakim will bring gusty winds and it will drop locally heavy rain over Madagascar.  The heavy rain is likely to cause flash floods in some areas.

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.