Category Archives: Indian Ocean

Tropical Cyclone Idai Makes Landfall in Mozambique

Strong Tropical Cyclone Idai made landfall in Mozambique very close to Beira on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Idai was located at latitude 19.4°S and longitude 34.5°E which put it about 30 miles (50 km) northwest of Beira, Mozambique.  Idai was moving toward the west at 8 m.p.h. (13 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 958 mb.

The core of Tropical Cyclone Idai moved directly over Beira, Mozambique.  The eye moved over Beira.  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h) at the time of landfall.  Winds to hurricane/typhoon force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles from the center of Tropical Cyclone Idai.

The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 19.2 at the time of landfall.  The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 33.0.  Tropical Cyclone Idai was capable of causing very serious wind damage.  Both sides of the eyewall which contained the strongest winds moved over Beira.  The relatively slow rate at which Idai was moving would have resulted in a prolonged period of strong winds, which would have increased the potential for damage.

Clockwise rotation around Tropical Cyclone Idai would have produced strong southerly winds when Idai approached Beira.  Those winds would have pushed water into the mouth of the Rio Pungoe which is on the western side of Beria.  There could have been an enhanced storm surge of 12 to 18 feet (4 to 6 meters) in that area.  Beira is one of the largest cities in Mozambique and it has a population of over half a million people.  Idai could have cause very serious damage around Beira.

Tropical Cyclone Idai will move toward the west-northwest during the next day or two.  On its anticipated track Idai will move farther inland over Mozambique and it will eventually move over Zimbabwe.  Tropical Cyclone Idai will weaken steadily as it moves inland, but it will drop heavy rain over central Mozambique and over parts of Zimbabwe.  The heavy rain could cause flooding along portions of Rio Pungoe and Rio Buzi as well as other parts of central Mozambique and Zimbabwe.

Major Tropical Cyclone Idai Nears Mozambique

Major Tropical Cyclone Idai neared the coast of Mozambique on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Cyclone Idai was located at latitude 19.7°S and longitude 37.5°E which put it about 170 miles (275 km) east of Beira, Mozambique.  Idai was moving toward the west-southwest at 7 m.p.h. (11 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 949 mb.

Tropical Cyclone Idai strengthened back into the equivalent of a major hurricane after it completed an eyewall replacement cycle on Wednesday.  An eye with a diameter of 35 miles (55 km) appeared on satellite images after the remnants of the original inner eyewall weakened.  A ring of strong thunderstorms surrounded the large eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Idai.  Storms near the core of Idai were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The size of the circulation around Tropical Cyclone Idai increased during the eyewall replacement cycle.  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 155 miles (250 km from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 22.1.  The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 38.6.

Tropical Cyclone Idai will remain in an environment favorable for intensification until it reaches the coast of Mozambique.  Idai will move over water where the Sea Surface Temperature is near 30°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  Idai could strengthen before it reaches the coast.

Tropical Cyclone Idai will move north of a subtropical ridge over southern Africa.  The ridge will steer Idai toward the west.  On its anticipated track Tropical Cyclone Idai will make landfall on the coast of Mozambique near Beira in less than 24 hours.  Idai will bring very strong winds and it will be capable of causing regional major damage.  Tropical Cyclone Idai will also drop heavy rain over parts of Mozambique and it will likely cause flooding in some locations.

Tropical Cyclone Savannah Forms North of Cocos Island

Tropical Cyclone Savannah formed over the southeast Indian Ocean north of Cocos Island on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Savannah was located at latitude 11.3°S and longitude 96.7°E which put it about 60 miles (100 km) north of Cocos Island.  Savannah was moving toward the south-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 997 mb.  The Australian Bureau of Meteorology has issued a Tropical Storm Warning for Cocos Island.

More thunderstorms formed near an area of low pressure over the southeastern Indian Ocean west of Australia and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Savannah.  The distribution of thunderstorms around Savannah was asymmetrical.  Several bands of showers and thunderstorms developed in the western half of the circulation.  Rainbands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Tropical Cyclone Savannah was moving south of an upper level ridge.  The ridge was generating easterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.

Tropical Cyclone Savannah will move through an environment favorable for intensification during the next several days.  Savannah will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will continue to cause vertical wind shear, but the shear could decrease during the next 48 hours.  Tropical Cyclone Savannah is likely to intensify during the next day or two.

Tropical Cyclone Savannah will move near the western end of a strengthening subtropical ridge over Australia.  The ridge will steer Savannah toward the south-southwest during the next day or two.  On its anticipated track Tropical Cyclone Savannah will bring gusty winds and locally heavy rain to Cocos Island during the next 24 hours.

Tropical Cyclone Idai Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Idai strengthened into the equivalent of a major hurricane over the Mozambique Channel on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Idai was located at latitude 18.2°S and longitude 42.0°E which put it about 490 miles (785 km) east-northeast of Beira, Mozambique.  Idai was moving toward the southwest at 5 m.p.h. (8 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 952 mb.

Tropical Cyclone Idai intensified into the equivalent of a major hurricane on Monday and then it appeared to begin an eyewall replacement cycle.  A rainband wrapped around the original eye and eyewall.  Convergence became concentrated on the outer eyewall and the inner eyewall began to dissipate.  The overall size of the circulation increased.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 130 miles (210 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 20.6.  The Hurricane Size Index (HSI) was 15.2 and the Hurricane Wind Intensity Size Index (HWISI) was 35.8.

Tropical Cyclone Idai will remain in an environment favorable for intensification for several more days.  Idai 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 Idai could strengthen further once the inner eyewall dissipates completely and the eyewall replacement cycle ends.

Tropical Cyclone Idai will move around the southeastern part of a subtropical ridge over southern Africa.  The ridge will steer Idai on a course that is a little south of due west.  On its anticipated track Tropical Cyclone Idai could reach the coast of Mozambique near Beira in less than 72 hours.  Idai could still be the equivalent of a major hurricane when it reaches the coast.

Tropical Cyclone Idai Rapidly Intensifies Into Equivalent of Hurricane/Typhoon

Tropical Cyclone Idai rapidly intensified into the equivalent of a hurricane/typhoon over the Mozambique Channel on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Cyclone Idai was located at latitude 17.4°S and longitude 43.2°E which put it about 75 miles (120 km) northwest of Maintirano, Madagascar.  Idai was moving toward the south at 1 m.p.h. (2 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 958 mb.

Tropical Cyclone Idai intensified rapidly on Sunday.  An eye was apparent on satellite imagery,  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 Idai.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to hurricane/typhoon force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Idai was 17.8.  The Hurricane Size Index (HSI) was 10.7 and the Hurricane Wind Intensity Size Index (HWISI) was 28.5.

Tropical Cyclone Idai will continue to move through an environment favorable for intensification during the next day or two,  Idai 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 Idai could intensify into the equivalent of a major hurricane during the next 24 hours.

Tropical Cyclone Idai will move around the eastern end of a subtropical ridge over southern Africa. The ridge will steer Idai toward the west during the next several days.  On its anticipated track Tropical Idai could approach the coast of Mozambique in about four days.  Idai could be the equivalent of a major hurricane at that time.

Tropical Cyclone Idai Forms Over Mozambique Channel

Tropical Cyclone Idai formed over the Mozambique Channel on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Idai was located at latitude 17.2°S and longitude 42.5°E which put it about 135 miles (220 km) west-northwest of Maintirano, Madagascar.  Idai was moving toward the southeast 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 60 m.p.h. (95 km/h).  The minimum surface pressure was 994 mb.

The circulation around Tropical Cyclone Idai organized quickly on Saturday.  The inner portion of a rainband wrapped around the eastern and southern sides of the center of circulation.   Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Idai.  Storms near the core began to generate upper level divergence which pumped mass away from the tropical cyclone.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Idai will move through an environment favorable for intensification during the next several days.  Idai 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 Idai will continue to intensify and it could strengthen into the equivalent of a hurricane/typhoon within 36 hours.  Once the inner core is fully organized, Idai could strengthen rapidly and it could intensify into the equivalent of a major hurricane.

Tropical Cyclone Idai will move around the eastern end of a subtropical ridge over southern Africa.  The ridge will steer Idai back toward the west.  On its anticipated track Tropical Cyclone Idai could approach the coast of Mozambique in about four days.  Idai could be the equivalent of a major hurricane by that time.

Tropical Cyclone Haleh Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Haleh strengthened into the equivalent of a major hurricane on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Cyclone Haleh was centered at latitude 18.9°S and longitude 72.3°E which put it about 800 miles (1290 km) south of Diego Garcia.  Haleh was moving toward the south-southwest at 10 m.p.h. (16 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 948 mb.

Tropical Cyclone Haley rapidly intensified into the equivalent of a major hurricane during the past 24 hours.  A circular eye was clearly evident on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Haleh.  The strongest bands were in the southern half of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.

Winds to hurricane/typhoon force extended out about 50 miles (80 km) from the center of Tropical Cyclone Haleh.  Winds to tropical storm force extended out about 210 miles (330 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Haleh was 22.1.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 38.1.

Tropical Cyclone Haleh will move through an environment favorable for intensification during the next 24 hours.  Haleh will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Tropical Cyclone Haleh could intensify during the next day or so.  Eventually, Haleh will move over cooler water and it will start to weaken when that occurs.

Tropical Cyclone Haleh will move around the western end of a subtropical ridge over the South Indian Ocean.  The ridge will steer Haleh toward the south-southwest.  On its anticipated track Tropical Cyclone Haleh is forecast to remain well to the southeast of Mauritius and La Reunion.

Tropical Cyclone Haleh Develops Southeast of Diego Garcia

Tropical Cyclone Haleh developed southeast of Diego Garcia on Saturday.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Haleh was located at latitude 13.5°S and longitude 73.9°E which put it about 435 miles (700 km) south-southeast of Diego Garcia.  Haleh was moving toward the south-southwest at 8 m.p.h. (13 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 981 mb.

The circulation around Tropical Cyclone Haleh organized quickly on Saturday.  An inner rainband wrapped around the southern and western sides of the center of circulation.  Other bands of showers and thunderstorms were revolving around the core of Haleh.  The strongest rainbands were occurring in the eastern half of the circulation.  Rainbands in the western half of the circulation consisted mostly of showers and lower clouds.  Storms near the core of Haleh were generating upper level divergence which was pumping mass away to the southeast of the tropical cyclone.  Winds to tropical storm force extended out about 160 miles (260 km) from the center of circulation.

Tropical Cyclone Haleh will move through an environment favorable for intensification during the next several days.  Haleh will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough to the west of Tropical Cyclone Haleh will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Haleh is forecast to intensify into the equivalent of a hurricane/typhoon.

Tropical Cyclone Haleh will move around the northwestern part of a subtropical ridge over the South Indian Ocean.  The ridge will steer Haleh toward the southwest during the next few days.  On its anticipated track Tropical Cyclone Haleh will remain well to the south of Diego Garcia.

Tropical Cyclone Gelena Brings Wind and Rain to Rodrigues

Tropical Cyclone Gelena brought wind and rain to Rodrigues on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Gelena was located at latitude 20.5°S and longitude 63.7°E which put it about 55 miles (90 km) southeast of Rodrigues, Mauritius.  Gelena was moving toward the east-southeast at 18 m.p.h. (29 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 959 mb.

Tropical Cyclone Gelena was the equivalent of a major hurricane when it moved past Rodrigues.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Gelena was 20.6.  The Hurricane Size Index (HSI) was 15.9 and the Hurricane Wind Intensity Size Index (HWISI) was 36.5.

The northeastern part of the eyewall of Tropical Cyclone Gelena appeared to cross Rodrigues.  Winds to hurricane/typhoon force may have occurred when that part of the eyewall moved over the island.  Winds to tropical storm force will continue for a few more hours until Gelena moves farther away from Rodrigues.  Conditions on Rodrigues should gradually improve on Sunday while Tropical Cyclone Gelena moves farther away.  Gelena will weaken as it moves over colder water.

Elsewhere over South Indian Ocean, Tropical Cyclone Funani made a transition to an extratropical cyclone.  At 4:00 p.m. EST the center of Tropical Cyclone Funani was located at latitude 31.9°S and longitude 77.4°E which put it about 1390 miles (2245 km) southeast of Mauritius.  Funani was moving toward the southeast at 28 m.p.h. (45 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 996 mb.

Tropical Cyclone Gelena Strengthens to Equivalent of a Major Hurricane

Tropical Cyclone Gelena strengthened into the equivalent of a major hurricane on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Gelena was located at latitude 16.8°S and longitude 56.9°E which put it about 265 miles (425 km) north of Port Louis, Mauritius.  Gelena was moving toward the southeast at 15 m.p.h. (24 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. (205 km/h).  The minimum surface pressure was 953 mb.

The circulation around Tropical Cyclone Gelena strengthened and grew larger on Friday.  An eye appeared intermittently at the center of Gelena on satellite imagery.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in the ring of storms.  More bands of showers and thunderstorms were revolving around the core of the circulation.  Winds to hurricane/typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 175 miles (280 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Gelena was 23.6.  The Hurricane Size Index (HSI) was 17.3 and the Hurricane Wind Intensity Size Index (HWISI) was 40.9.  Those indices indicated that tropical Cyclone Gelena was capable of causing major regional damage.

Tropical Cyclone Gelena will move through an environment somewhat favorable for intensification for another 12 to 24 hours.  Gelena will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough near Madagascar will produce westerly winds which are blowing toward the top of Tropical Cyclone Gelena.  Those winds will produce some vertical wind shear and they will inhibit upper level divergence toward the western periphery of Gelena.  The wind shear will inhibit intensification, but Tropical Cyclone Gelena could strengthen on Saturday.

Tropical Cyclone Gelena will move south of a subtropical ridge.  The ridge will steer Gelena in a southeasterly direction.  On its anticipated track Tropical Cyclone Gelena will pass north of Mauritius.  However, Gelena could approach Rodrigues within 36 hours.  Tropical Cyclone Gelena could bring strong winds and heavy rain to Rodrigues.

Elsewhere over the southern Indian Ocean, Tropical Cyclone Funani was speeding toward colder water.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Funani was located at latitude 26.3°S and longitude 73.4°E which put it about 805 miles (1295 km) east-southeast of Rodrigues.  Funani was moving toward the southeast at 28 m.p.h. (45 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 977 mb.