Category Archives: Indian Ocean

Tropical Cyclone Sagar Strengthens Over Western Gulf of Aden

Tropical Cyclone Sagar strengthened over the western Gulf of Aden on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Sagar was located at latitude 11.2°N and longitude 45.0°E which put it about 105 miles (170 km) south of Aden, Yemen.  Sagar was moving toward the west-southwest at 5 m.p.h. (8 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 986 mb.

A small eye appeared at the center of Tropical Cyclone Sagar on microwave satellite imagery.  The eye was surrounded by a tight ring of thunderstorms and the strongest winds were occurring in the ring of storms.  There was a small break on the southeast side of the ring of storms.  A short, broad band of showers and thunderstorms wrapped around the western and northern sides of the core of the circulation.  A longer, thinner rainband wrapped around the southern and eastern periphery of the circulation.  Storms near the core of Tropical Cyclone Sagar were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 60 miles (95 km) from the center of circulation.

Tropical Cyclone Sagar will be moving through an environment favorable for intensification for about another 12 to 18 hours.  Sagar will move over water where the Sea Surface Temperature is near 29°C to 30°C.  It is moving south of an upper level ridge.  The ridge is generating easterly winds which are blowing toward the top of the circulation.  Those winds are producing some vertical wind shear.  The shear may be the reason why most of the stronger thunderstorms are in the western half of the circulation.  The shear will inhibit intensification, but it will not be strong enough to prevent further strengthening.  Tropical Cyclone Sagar could become the equivalent of a hurricane/typhoon.  Much drier air is over eastern Africa and the Arabian Peninsula.  When Tropical Cyclone Sagar nears the coast of western Somalia, it will pull some of the drier air into the circulation and that will cause Sagar to start to weaken.

The upper level ridge is steering Tropical Cyclone Sagar toward the west-southwest and that general motion is expected to continue for several more days.  On its anticipated track Tropical Cyclone Sagar could make landfall on the coast of western Somalia in 18 to 24 hours.  Sagar will be capable of causing minor wind damage.  It could produce a storm surge of 4 to 8 feet (1.5 to 2.5 meters) near where the center makes landfall.  The core of Tropical Cyclone Sagar could also drop locally heavy rain over parts of western Somalia and eastern Ethiopia.  Heavy rain could cause flash floods in some locations.

Tropical Cyclone Sagar Strengthens Over Gulf of Aden

Tropical Cyclone Sagar (01A) strengthened over the Gulf of Aden on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Sagar was located at latitude 12.8°N and longitude 47.8°E which put it about 210 miles (335 km) east of Aden, Yemen.  Sagar was moving toward the west-southwest at 8 m.p.h. (13 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 992 mb.

The circulation of Tropical Cyclone Sagar became more organized on Thursday.  An eyelike feature appeared at the center of circulation.  A partial ring of thunderstorms wrapped around the northeast, northwest and southwest quadrants of the incipient eye.  There was a break in the ring of storms southeast of the center.  The strongest winds were occurring in the partial ring.  Additional bands of showers and thunderstorms were occurring north and west of the center of circulation.  Bands south and east of the center consisted primarily of low clouds and showers.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 70 miles (110 km) from the center of circulation.

Tropical Cyclone Sagar will move through an environment somewhat favorable for intensification during the next 24 to 36 hours.  Sagar will move over water where the Sea Surface Temperature is near 29°C to 30°C.  So, there is plenty of energy in the upper ocean to support intensification.  Sagar is moving south of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing some vertical wind shear and they are part of the reason why the strong storm are occurring mainly in the western half of the circulation.  The wind shear is not strong enough to prevent intensification and Tropical Cyclone Sagar is likely to continue to strengthen during the next 24 hours.  It could strengthen into the equivalent of a hurricane/typhoon.  Much drier air is over the Arabian Peninsula and Somalia.  When Sagar approaches the coast of the Gulf of Aden, it will start to pull drier air into the circulation and that will cause Sagar to weaken.

The upper level ridge is steering Tropical Cyclone Sagar toward the west-southwest and that general motion is expected to continue during the next several days.  On its anticipated track Tropical Cyclone Sagar could be south of Aden in about 36 hours.  Sagar could approach the coast of western Somalia and Djibouti in two or three days.  Tropical Cyclone Sagar will bring gusty winds and it could cause some storm surge at the coast.  The greater risk is for locally heavy rain near the coast of Yemen and over north Somalia.  The rain could be heavy enough to produce flash floods in some locations.

Tropical Cyclone 01A Forms Over the Gulf of Aden

Tropical Cyclone 01A formed over the Gulf of Aden on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone 01A was located at latitude 13.0°N and longitude 48.6°E which put it about 265 miles (425 km) east of Aden, Yemen.  It was moving toward the west 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 distinct low level center of circulation developed in an area of showers and thunderstorms that moved from the Arabian Sea to the Gulf of Aden.  Several bands of stronger thunderstorms formed west of the center of circulation and the strongest winds were occurring in these bands.  Bands in the eastern half of the circulation consisted primarily of low clouds and showers.  The storms west of the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 60 miles (95 km) from the center of circulation.

Tropical Cyclone 01A will move through an environment somewhat 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 01A is moving south of an upper level ridge.  The ridge is producing westerly winds which were blowing toward the top of the circulation.  Those winds may be part of the reason why the stronger thunderstorms are occurring on the western side of the center  The winds are causing some vertical wind shear, but the shear is not likely to be strong enough to prevent intensification.  Tropical Cyclone 01A is likely to strengthen as long as it stays over the Gulf of Aden and it could intensify into the equivalent of a hurricane.  Much drier air is over the Arabian Peninsula and over eastern Africa.  Tropical Cyclone 01A will likely weaken when it moves closer to land and starts to pull drier air into the circulation.

The upper level ridge is steering Tropical Cyclone 01A toward the west.  The ridge is forecast to strengthen and to steer the tropical cyclone a little to the south of west during the next several days.  On its anticipated track Tropical Cyclone 01A is expected to remain over the Gulf of Aden for several more days.  Bands of showers and thunderstorms could bring locally heavy rain to coastal portions of Yemen and northern parts of Somalia.

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 Fakir Brings Wind and Rain to Mauritius and La Reunion

Tropical Cyclone Fakir brought wind and rain to Mauritius and La Reunion on Tuesday.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Fakir was located at latitude 21.9°S and longitude 56.6°E which put it about 80 miles (130 km) southeast of St. Denis, La Reunion.  Fakir was moving toward the southeast at 25 m.p.h. (40 km/h).  The maximum sustained wind 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 983 mb.  Fakir was the equivalent of a hurricane/typhoon.

The center of Tropical Cyclone Fakir passed between Mauritius and La Reunion on Tuesday and it brought gusty winds and heavy rain.  An eye formed at the center of circulation and a narrow ring of thunderstorms wrapped tightly around the eye.  The strongest winds were occurring in the ring of storms.  Bands of showers and thunderstorms were occurring south and east of the center of circulation.  The bands north and west of the center consisted primarily of light showers and low clouds.  Winds to tropical storm force extended out about 170 miles (270 km) from the center.

Tropical Cyclone Fakir was capable of causing minor wind damage on Mauritius and La Reunion.  Fakir was also dropping heavy rain and the rain was likely to produce flash floods in some locations.  Tropical Cyclone Fakir was moving rapidly to the southeast.  So, conditions on Mauritius and La Reunion are likely to improve later on Tuesday when the core of Fakir moves away.  Fakir has peaked in intensity.  Although it is moving over water where the Sea Surface Temperature is near 27°C, Tropical Cyclone Fakir has moved under an area of strong upper level winds blowing from the northwest.  Those winds will cause strong vertical wind shear, which will weaken Fakir.

Tropical Cyclone Fakir Strengthens Rapidly Northwest of La Reunion

Tropical Cyclone Fakir strengthened rapidly northwest of La Reunion on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Fakir was located at latitude 18.2°S and longitude 54.5°E which put it about 220 miles (355 km) north-northwest of St. Denis, La Reunion.  Fakir was moving toward the southeast at 22 m.p.h. (35 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 992 mb.

A center of circulation developed early Monday in an area of thunderstorms east of Madagascar and the system was designated as Tropical Cyclone Fakir.  The circulation organized quickly and in a few hours Fakir strengthened into the equivalent of a strong tropical storm.  A primary rainband wrapped around the southern and western sides of the center of circulation.  There were some indications of the potential development of an eye at the center.  Additional bands of showers and thunderstorms developed south and east of the core of Tropical Cyclone Fakir.  Storms in the core of Fakir generated strong upper level divergence which pumped away mass to the southeast of the circulation.  The removal of mass allowed the surface pressure to decrease quickly and the winds to increase in response to that decrease.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Fakir could remain in an environment favorable for intensification for another 12 to 18 hours.  Fakir will move over water where the Sea Surface Temperature is near 28°C.  So, there is sufficient energy in the upper ocean to support intensification.  Tropical Cyclone Fakir is moving around the southwestern portion of an upper level ridge located over the South Indian Ocean.  The ridge is producing northwesterly winds which were blowing toward the top of the circulation.  The winds were causing moderate vertical wind shear, but they were not strong enough to prevent Fakir from strengthening rapidly on Monday.  Tropical Cyclone Fakir could become the equivalent of a hurricane/typhoon during the next 12 to 18 hours.  Fakir will move under stronger upper level winds in a day or so and then it will start to weaken because of the stronger vertical wind shear.

The upper level ridge is steering Tropical Cyclone Fakir rapidly toward the southeast and that general motion is expected to continue for several more days.  On its anticipated track Tropical Cyclone Fakir will approach Mauritius and La Reunion in about 12 hours.  It could be nearly the equivalent of a hurricane/typhoon at that time.  Fakir will bring gusty winds and heavy rain to Mauritius and La Reunion.  Minor wind damage is possible.  Locally heavy rain could cause flash floods.  The most likely track takes the center of Tropical Cyclone Fakir between Mauritius and La Reunion.  The western side of the circulation is a little weaker than the eastern side is.  If Fakir follows that track, then the strongest wind and heaviest rain could affect Mauritius.  However, Fakir will also affect La Reunion.

Tropical Cyclone Nora Develops Rapidly North of Australia

Tropical Cyclone Nora developed rapidly north of Australia over the Arafura Sea on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Nora was located at latitude 10.0°S and longitude 136.8°E which put it about 160 miles (260 km) north of Nhulunbuy, Australia.  Nora was moving toward the east at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 986 mb.

A center of circulation organized quickly on Thursday in an area of thunderstorms over the Arafura Sea and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Nora.  A primary rainband wrapped around the western and northern side of the center of circulation.  An eye appeared to be forming at the center of Tropical Cyclone Nora.  Bands of showers and thunderstorms were revolving around the core of the circulation.  Storms around the core were generating well developed upper level divergence which was pumping mass away from the tropical cyclone.  The removal of mass was allowing the surface pressure to decrease rapidly and the wind speeds were increasing in response.

The Australian Bureau of Meteorology issued Warnings for the portions of the coast from Elcho Island to Cape Shield including Cape Wessel and from Pormpuraaw to Thursday Island.  A Watch was in effect for the portion of the coast from Pormpuraaw to the border between the Northern Territory and Queensland including Mornington Island.

Tropical Cyclone Nora will move through an environment very favorable for intensification during the next 48 hours.  Nora 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 is little vertical wind shear.  Nora is likely to intensify rapidly and it is likely to become the equivalent of a hurricane/typhoon within 24 hours.  Tropical Cyclone Nora could become the equivalent of a major hurricane within 24 to 48 hours.

Tropical Cyclone Nora was moving through an area where steering winds are weak and it was moving slowly toward the east.  A subtropical ridge east of Australia is expected to strengthen.  The ridge is forecast to steer Nora more toward the south in 12 to 24 hours.  On its anticipated track Tropical Cyclone Nora is expected to move over the Gulf of Carpentaria toward the coast of Queensland.  Nora could strengthen into a dangerous tropical cyclone.

Elsewhere, Tropical Cyclone Marcus continued to churn west of Australia.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Marcus was located at latitude 20.6°S and longitude 106.0°E which put it about 555 miles (895 km) west-northwest of Learmonth, Australia.  Marcus was moving toward the south at 13 m.p.h. (21 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 951 mb.

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.