Category Archives: Indian Ocean

Tropical Cyclone Diane Forms North of La Reunion

Tropical Cyclone Diane formed north of La Reunion on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Cyclone Diane was located at latitude 19.3°S and longitude 56.2°E which put it about 110 miles (175 km) north-northeast of St. Denis, La Reunion.  Diane was moving toward the east-southeast at 18 m.p.h. (30 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 997 mb.

A distinct low level center of circulation developed in an area of low pressure east of Madagascar on Friday and the system was designated as Tropical Cyclone Diane.  The distribution of thunderstorms around Tropical Cyclone Diane was asymmetrical.  Many of the stronger thunderstorms were occurring northwest of the center of circulation.  Bands of showers and thunderstorms were developing east of the center of Diane.  Storms near the center of circulation were beginning to generate upper level divergence which was pumping mass away to the southeast of the tropical cyclone.

Tropical Cyclone Diane will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Diane will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough west of Madagascar and an upper level ridge east of Mauritius will interact to produce northwesterly winds which will blow toward the top of the tropical cyclone.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  Tropical Cyclone Diane could intensify slowly during the next 24 to 36 hours.

The upper level trough and upper level ridge will steer Tropical Cyclone Diane toward the east-southeast during the next several days.  On its anticipated track Tropical Cyclone Diane could bring wind and rain to Mauritius within 12 hours.  Locally heavy rain could cause flash floods in some locations.

Tropical Cyclone Claudia Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Claudia strengthened into the equivalent of a hurricane/typhoon over the South Indian Ocean northwest of Australia on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Claudia was located at latitude 16.0°S and longitude 117.9°E which put it about 290 miles (465 km) north of Port Hedland, Australia.  Claudia was moving toward the west-southwest at 25 m.p.h. (40 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 971 mb.

Tropical Cyclone Claudia strengthened over the warm water northwest of Australia on Sunday.  A small circular eye formed 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 Claudia.  The stronger rainbands were in the western half of the circulation.  Bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Storms near the core of the circulation were generating upper level divergence which was pumping mass away to the west of the tropical cyclone.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center.

Tropical Cyclone Claudia will move through an environment favorable for intensification during the next 24 hours.  Claudia will move over water where the Sea Surface Temperature is near 30°C.  It will move around the northwestern part of an upper level ridge centered over Australia.  The ridge will produce easterly winds which will blow toward the top of the tropical cyclone.  Those winds will produce moderate vertical wind shear.  The wind shear will slow the rate of intensification, but the shear will not be strong enough to prevent Claudia from getting strong during the next 24 hours.

Tropical Cyclone Claudia will move around the northwestern side of a high pressure system over Australia.  The high will steer Claudia toward the west-southwest.  On its anticipated track the core of Tropical Cyclone Claudia will remain well off the coast of Western Australia.

Tropical Cyclone Claudia Develops Northwest of Australia

Tropical Cyclone Claudia developed northwest of Australia on Saturday.  At 1:00 p.m. EST on Saturday the center of Tropical Cyclone Claudia was located at latitude 13.2°S and longitude 125.4°E which put it about 155 miles (250 km) north-northeast of Kuri Bay, Australia.  Claudia was moving toward the west-southwest at 11 m.p.h. (18 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.

The Australian Bureau of Meteorology issued a Warning for the portion of the coast of Western Australia from Kalumburu to Beagle Bay.  The Warning zone includes Kuri Bay and Cape Leveque.

A Tropical Low moved westward across northern Australia late last week.  The circulation around the low pressure system began to organize when the system moved over Timor Sea west of Darwin on Saturday.  The wind speed increased and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Claudia.  The inner end of a rainband wrapped around the northern and eastern sides of the center of circulation.  Thunderstorms formed quickly in other bands north and west of the center.  There were fewer thunderstorms in rainbands south and east of the center, but much of that part of the circulation was still over western Australia.  Storms near the center of circulation began to generate upper level divergence which pumped mass to the west of the tropical cyclone.

Tropical Cyclone Claudia will move through an environment favorable for intensification during the next several days.  Claudia will move over water where the Sea Surface Temperature is near 30°C.  It will move around the northwestern part of an upper level ridge centered over Australia.  The ridge will produce easterly winds which will blow toward the tropical cyclone.  Those winds will cause moderate vertical wind shear.  The wind shear will slow the rate of intensification but it will not be strong enough to keep Tropical Cyclone Claudia from strengthening.  Claudia could intensify into the equivalent of a hurricane/typhoon during the next 24 to 48 hours.

Tropical Cyclone Claudia will move around the northwestern part of a high pressure system over Australia.  The high will steer Claudia toward the west-southwest.  On its anticipated track the center of Tropical Cyclone Claudia will move parallel to the coast of Western Australia.  The core of Claudia with the strongest winds is forecast to remain offshore.

Tropical Cyclone Blake Makes Another Landfall in Western Australia

Tropical Cyclone Blake made another landfall on the coast of Western Australia on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Blake was located at latitude 20.1°S and longitude 120.5°E which put it about 20 miles (35 km) south-southwest of Wallal Downs, Australia.  Blake was moving toward the southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 55 m.p.h. (90 km/h).  The minimum surface pressure was 990 mb.

The center of Tropical Cyclone Blake moved across the coast of Western Australia just to the west of Wallal Downs on Tuesday.  Blake was beginning to weaken, but winds to tropical storm force were still occurring in the northwestern part of the circulation that was still over water.  A weather station at Bedout Island which is just off the coast of Western Australia was reporting a sustained wind speed of 43 m.p.h. (69 km/h) and wind gusts to 50 m.p.h. (82 km/h).  A weather station in Mandora, Australia had already received 2.69 inches (64.4 mm) of rain from the rainbands in eastern side of the tropical cyclone.

Tropical Cyclone Blake will move around the western end of a high pressure system over Australia.  Blake will move more toward the south when it reaches the western end of the high.  On its anticipated track the center of Tropical Cyclone Blake could be near Marble Bar in about 12 hours.  Blake could approach Newman in about 24 hours.  Tropical Cyclone Blake will weaken as it moves farther inland.  Blake could drop locally heavy rain over parts of Western Australia and the potential for flash floods exists.

Elsewhere, a Tropical Low was slowly organizing over the Arafura Sea north of Australia.  At 1:00 p.m. EST on Tuesday the center of the Tropical Low was located at latitude 11.2°S and longitude 137.7°E which put it about 70 miles (115 km) north-northeast of Nhulunbuy, Australia.  The Tropical Low was moving toward the west at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1003 mb.  The Tropical Low is forecast to move westward and to strengthen.  A Watch has been issued for the portions of the coast from Cape Don to Point Stuart and from Goulburn Island to Cape Shield.

Tropical Cyclone Blake Brings Wind and Rain to Western Australia

Tropical Cyclone Blake brought wind and rain to portions of Western Australia on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Blake was located at latitude 18.7°S and longitude 121.5°E which put it about 60 miles (95 km) southwest of Broome, Australia.  Blake was moving toward the south-southwest at 7 m.p.h. (11 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 989 mb.

The center of Tropical Cyclone Blake made landfall on the coast of Western Australia north of Broome earlier on Monday.  The center moved back out over water slightly north of Broome and then the center passed just to the west of that city.  A weather station in Broome measured sustained winds of 30 m.p.h. (50 km/h) and a wind gust to 50 m.p.h. (82 km/h).  5.83 inches (148 mm) of rain fell over Broome.  A rainband in the northeastern periphery of the circulation dropped rain over the area around the Kimberly Plateau during much of Monday.

Tropical Cyclone Blake weakened while the center was over land, but it appears to be strengthening again now that the center is back over water.  More thunderstorms developed near the center of circulation during the past few hours.  Those storms started to generated upper level divergence again.  Bands farther away from the center consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation mainly in portions of circulation over water.

Tropical Cyclone Blake will move through an environment favorable for intensification during the next 12 hours.  Blake will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Blake could strengthen during the next 12 hours.

Tropical Cyclone Blake will move around the western end of a high pressure system over Australia.  The high will steer Blake toward the south-southwest during the next 24 to 36 hours.  On its anticipated track Tropical Cyclone Blake could make another landfall on the coast of Western Australia near Wallal Downs.  A Warning is in effect for the portion of the coast from Bidyadanga to De Grey.  Blake will bring gusty winds and rain to that portion of the coast.

Elsewhere, a new Tropical Low developed over the Arafura Sea north of Australia.  At 8:00 p.m. EST on Monday the center of the Tropical Low was located at latitude 10.7°S and longitude 137.7°E which put it about 120 miles (195 km) north-northeast of Nhulunbuy, Australia.  The Tropical Low was moving toward the east at 6 m.p.h. (9 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1003 mb.  The Tropical Low is forecast to move back toward the west and to strengthen.  A Watch has been issued for the portion of the Australian coast from Cape Shield to Cape Don including Goulburn Island.  On its anticipated track the center of the Tropical Low could pass near Cape Wessel in about 24 hours.

Tropical Cyclone Blake Strengthens Near Western Australia

Tropical Cyclone Blake strengthened near Western Australia on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Blake was located at latitude 16.1°S and longitude 121.9°E which put it about 140 miles (220 km) north of Broome, Australia.  Blake was moving toward the east-southeast at 7 m.p.h. (11 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 995 mb.

A Warning has been issued for the portion of the coast of Western Australia from Kuri Bay to De Grey including Broome.  A Watch has been issued for the portion of the coast from De Grey to Whims Creek including Port Hedland.

The circulation around a Tropical Low over the South Indian Ocean northwest of Australia became more organized on Sunday night and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Blake.  The inner end of a rainband wrapped around the southern and western sides of the center of circulation.  Storms near the center of circulation began to generate upper level divergence which pumped mass away from the tropical cyclone.  Many of the thunderstorms were occurring in a primary rainband on the eastern side of Blake.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Tropical Cyclone Blake will move through an environment favorable for intensification during the next 24 to 36 hours.  Blake will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Blake will continue to intensify and it could strengthen into the equivalent of a hurricane/typhoon.

The center of Tropical Cyclone Blake shifted eastward on Sunday as the circulation reorganized closer to the inner end of the primary rainband.  Blake will move around the western end of a high pressure system centered near northern Australia.  The high will steer Blake toward the south-southwest.  On its anticipated track the center of Tropical Cyclone Blake will pass just west of Broome in about 24 hours.  Blake could make landfall on the coast of Western Australia near Wallal Downs in about 36 hours.  Tropical Cyclone Blake will bring gusty winds and locally heavy rain to the coast of Western Australia.

Tropical Low Forms Northwest of Australia

A Tropical Low formed over the South Indian Ocean northwest of Australia on Saturday.  At 1:00 p.m. EST on Saturday the center of a Tropical Low was located at latitude 14.3°S and longitude 121.9°E which put it about 255 miles (410 km) north of Broome, Australia.  It was moving toward the south-southwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1002 mb.

A Watch was issued for the portion of Western Australia from Mitchell Plateau to Wallal Downs.

The circulation around the Tropical Low was still organizing.  It did not have a well developed center of circulation.  There was a clockwise rotation around a broad center.  Bands of showers and thunderstorms were beginning to form in the outer regions of the circulation.  Upper level divergence was pumping mass away from the Tropical Low and the surface pressure was decreasing.

The Tropical Low will move through an environment favorable for intensification during the next 24 to 48 hours.  It will move over water where the Sea Surface Temperature is near 30°C.  The Tropical Low will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The Tropical Low is likely to intensify into a named tropical cyclone and it could strengthen into the equivalent of a hurricane/typhoon.

The Tropical Low will move around the western end of a high pressure system centered near the north coast of Australia.  The high will steer the Tropical Low toward the south-southwest.  On its anticipated track the Tropical Low could approach the coast of Western Australia southwest of Cape Leveque in a day or two.

Tropical Cyclone Calvinia Develops East of Mauritius

Tropical Cyclone Calvinia developed east of Mauritius on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Calvinia was located at latitude 20.7°S and longitude 58.7°E which put it about 105 miles (165 km) east-southeast of Port Louis, Mauritius.  Calvinia 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 998 mb.

A distinct low level center of circulation developed in an area of thunderstorms east of Mauritius on Sunday and the system was designated at Tropical Cyclone Calvinia.  The circulation around Tropical Cyclone Calvinia was asymmetrical.  Many of the stronger thunderstorms were occurring in bands on the eastern side of the circulation.  Bands north and west of the center of Calvinia consisted primarily of showers and lower clouds.  The distributions of strong winds around the tropical cyclone was also asymmetrical.  Winds to tropical storm force extended out 200 miles (320 km) on the eastern side of the circulation.  Winds to tropical storm force only extended out 60 miles (95 km) on the western side.

Tropical Cyclone Calvinia will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Calvinia will move over water where the Sea Surface Temperature is near 27°C.  It will move east of an upper level trough.  The trough will produce northwesterly winds which will blow toward the top of the circulation.  The winds will cause moderate vertical wind shear and they are probably the reason for the asymmetrical structure of Tropical Cyclone Calvinia.  Calvinia could strengthen during the next several days, but the wind shear is likely to prevent significant intensification.

The upper level trough will steer Tropical Cyclone Calvinia toward the southeast.  On its anticipated track Calvinia will move away from Mauritius and La Reunion.  Since Tropical Cyclone Calvinia will be east of Mauritius, the strongest part of the circulation will remain east of Mauritius and La Reunion.

Tropical Cyclone Belna Makes Landfall in Western Madagascar

Tropical Cyclone Belna made landfall in the west coast of Madagascar near Soalala on Monday.  At 9:00 a.m. EST on Monday the center of Tropical Cyclone Belna was located at latitude 16.0°S and longitude 45.0°E which put it about 20 miles (30 km) west-southwest of Soalala, Madagascar.  Belna was moving toward the south-southwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 974 mb.

Tropical Cyclone Belna made landfall near Soalala, Madagascar on Monday as the equivalent of a hurricane/typhoon.  There was a small circular eye at the center of Belna.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  The circulation around Tropical Cyclone Belna was relatively small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Belna was 13.9.  The Hurricane Size Index (HSI) was 7.1 and the Hurricane Wind Intensity Size Index (HWISI) was 21.0.  Belna was capable of causing localized serious damage.

Tropical Cyclone Belna will move around the western end of a subtropical high pressure system over the South Indian Ocean during the next 24 hours.  The high will steer Belna toward the south-southwest during that time period.  On it anticipated track Tropical Cyclone Belna will move across west central Madagascar.  Belna will weaken when it moves farther inland but it will bring gusty winds and heavy rain to the southwestern part of the district of Mahajanga.  Locally heavy rain could cause flash floods, especially in areas of steeper terrain.  Some rivers could rise very rapidly.

Tropical Cyclone Belna Approaches Northwest Madagascar

Tropical Cyclone Belna approached northwest Madagascar on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Belna was located at latitude 13.3°S and longitude 46.2°E which put it about 170 miles (275 km) north of Mahajanga, Madagascar.  Belna was moving toward the southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 965 mb.

Tropical Cyclone Belna strengthened into the equivalent of a hurricane/typhoon during the weekend.  The inner end of a rain band wrapped most the way around the center of circulation.  The strongest winds were occurring in the part of the rainband wrapped around the center.  Bands of showers and thunderstorms were revolving around the center of Belna.  The circulation around Tropical Cyclone Belna was small.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center.

Tropical Cyclone Belna will move through an environment favorable for intensification during the next 24 hours.  Belna will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Belna could strengthen if the inner core becomes better organized and a complete eyewall forms.  Belna will weaken once the center moves over land.  Since the circulation around Tropical Cyclone Belna is small, it will weaken fairly rapidly.

Tropical Cyclone Belna will move around the western end of a subtropical high pressure system over the South Indian Ocean.  The high will steer Belna toward the south-southwest during the next several days.  On its anticipated track the center of Tropical Cyclone Belna will make landfall on the northwest coast of Madagascar near Soalala in about 24 hours.  Belna will bring winds to near hurricane/typhoon force to locations near the coast.  Locally heavy rain will fall, especially in locations where the wind blows up the slopes of mountains.  Locally heavy rain coud cause flash floods in western Madagascar.