Tag Archives: HWISI

Typhoon Surigae Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Surigae rapidly intensified to the equivalent of a major hurricane on Friday. At 5:00 p.m. EDT on Friday the center of Typhoon Surigae was located at latitude 10.3°N and longitude 131.6°E which put it about 220 miles (330 km) northwest of Palau. Surigae was moving toward the west-northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 944 mb.

Typhoon Surigae rapidly intensified on Friday as it moved farther away from Palau. A small circular eye was present 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 Typhoon Surigae. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon in all directions. The removal of mass allowed the pressure to decrease rapidly.

The circulation around Typhoon Surigae increased in size on Friday. Winds to typhoon force extended out 50 miles (80 km) from the center of Surigae. Winds to tropical storm force extended out 180 miles (290 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 25.1. The Hurricane Size Index (HSI) was 18.8 and the Hurricane Wind Intensity Size Index (HWISI) was 43.9. Surigae was a large, dangerous typhoon capable of causing major damage.

Typhoon Surigae will move through an environment favorable for intensification during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the southwestern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the east and there will be little vertical wind shear. Typhoon Surigae will likely continue to intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Surigae to weaken.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next several days. The high will steer Surigae toward the northwest during the next 24 hours. After that time Typhoon Surigae will move more toward the north when it moves around the western end of the high pressure system. On its anticipated track Typhoon Surigae could be east of the Philippines in 36 hours.

Tropical Cyclone Habana Weakens

Tropical Cyclone Habana weakened over the South Indian Ocean east of Rodrigues on Friday. At 4:00 p.m. EST on Friday the center of Tropical Cyclone Habana was located at latitude 20.0°S and longitude 70.8°E which put it about 435 miles (700 km) east of Rodrigues. Habana was moving toward the south-southwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 954 mb.

Tropical Cyclone Habana weakened gradually over the South Indian Ocean on Friday. The temperature at the top of the clouds was not as cold, which indicated that the clouds were not rising as high in the atmosphere. Even though Habana was weakening it still was a very well organized tropical cyclone. There was an eye at the center of Tropical Cyclone Habana. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Storms around the core of generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Habana increased slightly in size. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Habana. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 23.6. The Hurricane Size Index (HSI) was 10.8 and the Hurricane Wind Intensity Size Index (HWISI) was 34.4.

Tropical Cyclone Habana will move through an environment that will gradually become less favorable for a strong tropical cyclone during the next several day. Habana will move over water where the Sea Surface Temperatures will be near 27°C. An upper level trough east of Madagascar will move toward Tropical Cyclone Habana. The trough will produce westerly winds which will blow toward the top of Habana. Those winds will cause more vertical wind shear and the shear will cause Tropical Cyclone Habana to weaken during the weekend.

Tropical Cyclone Habana will move around the western end of a subtropical high pressure system over the South Indian Ocean. The high will steer Habana toward the south during the next 24 hours. Then the high will strengthen and start to steer Habana toward the west again later in the weekend. On its anticipated track Tropical Cyclone Habana could be southeast of Rodrigues in a next few days.

Tropical Cyclone Habana Strengthens Back to Equivalent of Cat. 4 Hurricane

Tropical Cyclone Habana strengthened back to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale over the South Indian Ocean on Wednesday. At 4:00 p.m. EST on Wednesday the center of Tropical Cyclone Habana was located at latitude 17.4°S and longitude 75.1°E which put it about 750 miles (1210 km) east of Rodrigues. Habana was moving toward the west at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h). The minimum surface pressure was 935 mb.

Tropical Cyclone Habana strengthened back to the equivalent of a Category 4 hurricane over the South Indian Ocean east of Rodrigues on Wednesday. Microwave satellite images revealed the existence of concentric eyewalls in the middle of Habana. The small original eye and eyewall was surrounded by a larger outer eye. The strongest winds were still occurring in the smaller inner eyewall. Bands of showers and thunderstorms were revolving around the concentric eyewalls.

The formation of concentric eyewalls increased the size of the core of Tropical Cyclone Habana. However, the size of the overall circulation around Habana remained small. Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Habana. Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 31.6. The Hurricane Size Index (HSI) was 13.8 and the Hurricane Wind Intensity Size Index (HWISI) was 45.4.

Tropical Cyclone Habana will move through an environment capable of supporting a strong tropical cyclone during the next 36 hours. Habana will move over water where the Sea Surface Temperatures will be near 28°C. It will move under the axis of an upper level ridge over the South Indian Ocean. The winds are weak near the axis of the ridge and there will be little vertical wind shear. The formation of concentric eyewalls is likely to cause Tropical Cyclone Habana to weaken at least temporarily when the inner eyewall with the strongest winds dissipates. Habana could strengthen again if the outer eyewall being to contract.

Tropical Cyclone Habana will move north of a subtropical high pressure system over the South Indian Ocean. The high will steer Habana toward the west during the next several days. On its anticipated track Tropical Cyclone Habana will remain far to the south of Diego Garcia. Habana is forecast to still be east of Rodrigues during the next few days.

Tropical Cyclone Habana Moves West

Tropical Cyclone Habana moved west over the South Indian Ocean on Tuesday. At 4:00 p.m. EST on Tuesday the center of Tropical Cyclone Habana was located at latitude 17.8°S and longitude 77.7°E which put it about 950 miles (1500 km) east of Rodrigues. Habana was moving toward the west at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 969 mb.

Tropical Cyclone Habana strengthened on Tuesday as it moved westward over the South Indian Ocean. A small circular eye was evident again on infrared and microwave 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 Habana generated strong upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Habana was small. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Habana. Winds to tropical storm force extended out 75 miles (120 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 16.5. The Hurricane Size Index (HSI) was 8.9 and the Hurricane Wind Intensity Size Index (HWISI) was 25.4.

Tropical Cyclone Habana will move through an environment favorable for intensification during the next 36 hours. Habana will move over water where the Sea Surface Temperatures will be near 28°C. It will move under the axis of an upper level ridge over the South Indian Ocean. The winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Habana is likely to intensify to the equivalent of a major hurricane during the next 24 hours. Since the circulation around Habana is so small, the intensity could change rapidly.

Tropical Cyclone Habana will move north of a subtropical high pressure system over the South Indian Ocean. The high will steer Habana toward the west during the next several days. On its anticipated track Tropical Cyclone Habana will pass far to the south of Diego Garcia. Habana is forecast to remain east of Rodrigues during the next few days.

Tropical Cyclone Habana Expected to Move Westward

Tropical Cyclone Habana is expected to move westward during the upcoming week. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Habana was located at latitude 17.6°S and longitude 80.4°E which put it about 1150 miles (1850 km) east of Rodrigues. Habana was moving toward the southeast 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 959 mb.

Tropical Cyclone Habana continued to be the equivalent of a major hurricane. A small circular eye reappeared at the center of Habana on infrared satellite images on Sunday afternoon. The eye was surrounded by a ring of strong thunderstorms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Habana. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Habana was small. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Habana. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 20.6. The Hurricane Size Index (HSI) was 8.5 and the Hurricane Wind Intensity Size Index (HWISI) was 29.1.

Tropical Cyclone Habana will move through an environment capable of supporting a strong tropical cyclone during the next several days. Habana will move over water where the Sea Surface Temperatures will be near 28°C. It will move near the axis of an upper level ridge over the South Indian Ocean. The winds are weaker near the axis of the ridge and there will be little vertical wind shear. Since the core of Habana is so small, the inner end of a rainband could wrap around the existing eye and eyewall. In that case an eyewall replacement cycle would cause fluctuations in the intensity of Tropical Cyclone Habana.

A high pressure system located south of Tropical Cyclone Habana will strengthen during the next few days. That high pressure system will become the dominant weather system steering Habana. When the high pressure system strengthens, it will steer Tropical Cyclone Habana back toward the west. On its anticipated track Habana will pass far to the south of Diego Garcia. Tropical Cyclone Habana is forecast to remain east of Rodrigues during the upcoming week.

Elsewhere over the South Indian Ocean, Tropical Cyclone Iman was speeding away from La Reunion on Sunday afternoon. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Iman was located at latitude 24.7°S and longitude 58.5°E which put it about 320 miles (515 km) south-southeast of La Reunion. Iman was moving toward the east-southeast at 24 m.p.h. (35 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 990 mb. Tropical Cyclone Habana is forecast to make a transition to an extratropical cyclone during the next 48 hours.

Tropical Cyclone Iman Brings Rain to La Reunion

Tropical Cyclone Iman brought rain to La Reunion and Mauritius on Saturday night. At 7:00 p.m. EST on Saturday the center of Tropical Cyclone Iman was located at latitude 22.6°S and longitude 54.5°E which put it about 105 miles (165 km) south-southwest of La Reunion. Iman was moving toward the east-southeast at 23 m.p.h. (37 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.

An area of low pressure strengthened on Saturday after it moved over the South Indian Ocean east of Madagascar and Meteo France la Reunion designate the system as Tropical Cyclone Iman. The distribution of thunderstorms around Tropical Cyclone Iman was asymmetrical. The strongest thunderstorms were occurring in bands in the eastern half of Iman. Bands in the western half of the tropical cyclone consisted of primarily of showers and thunderstorms. Storms east of the center of circulation generated upper level divergence which pumped mass away to the southeast of the tropical cyclone.

Rainbands on the eastern side of Tropical Cyclone Iman brought gusty winds and locally heavy rain to La Reunion and Mauritius. Heavy rain could cause flash floods in some locations, especially in areas of steeper terrain.

An upper level trough south of Madagascar will steer Tropical Cyclone Iman toward the east-southeast. On its anticipated track Tropical Cyclone Iman will move quickly away to the southeast of La Reunion and Mauritius. Weather conditions in those locations will improve on Sunday.

Tropical Cyclone Iman will move into an environment that will be marginally favorable for intensification during the next 24 hours. Iman will move over water where the Sea Surface Temperatures will be near 27°C. The upper level trough will produce northwesterly winds which will blow toward the top of Iman. Those winds will cause more vertical wind shear and they will inhibit intensification.

Elsewhere over the South Indian Ocean, powerful Tropical Cyclone Habana maintained its intensity south-southeast of Diego Garcia. At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Habana was located at latitude 16.8°S and longitude 79.2°E which put it about 785 miles (1265 km) south-southeast of Diego Garcia. Habana was moving toward the southeast at 11 m.p.h. (17 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 945 mb.

The circulation around Tropical Cyclone Habana was small. Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Habana. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 28.3. The Hurricane Size Index (HSI) was 12.8 and the Hurricane Wind Intensity Size Index (HWISI) was 41.1.

Tropical Cyclone Niran Brings Wind and Rain to New Caledonia

Tropical Cyclone Niran brought wind and rain to New Caledonia on Friday night. At 10:00 p.m. EST on Friday the center of Tropical Cyclone Niran was located at latitude 21.8°S and longitude 165.0°E which put it about 165 miles (265 km) west-northwest of Noumea, New Caledonia. Niran was moving toward the east-southeast at 29 m.p.h. (46 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 955 mb.

Tropical Cyclone Niran weakened during its approach to New Caledonia. The inner end of a rainband wrapped around the original eye and eyewall, and concentric eyewalls formed. The maximum sustained wind speed decreased when the original, stronger eyewall weakened. Even though it weakened, Tropical Cyclone Niran was still the equivalent of a major hurricane.

Winds to hurricane/typhoon force extended out 65 miles (105 km) from the center of Tropical Cyclone Niran. Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Niran was 23.6. The Hurricane Size Index (HSI) was 24.1 and the Hurricane Wind Intensity Size Index (HWISI) was 47.7. Niran was capable of causing major damage.

The core of Tropical Cyclone Niran was passing just to the west of New Caledonia. The strongest winds around the core of Niran were remaining just west of the island. Tropical Cyclone Niran was producing gusty winds and it was dropping locally heavy rain over New Caledonia. Heavy rain could cause flash floods in some locations.

An upper level trough east of Australia will steer Tropical Cyclone Niran toward the east-southeast during the next two days. Niran will continue to weaken during that time period. The upper level trough will cause vertical wind shear and Tropical Cyclone Niran will move over cooler water. Weather conditions on New Caledonia should improve on Saturday when Niran moves rapidly away from the area.

Tropical Cyclone Habana Rapidly Intensifies to Equivalent of Cat. 4 Hurricane

Tropical Cyclone Habana rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale over the South Indian Ocean on Friday. At 4:00 p.m. EST on Friday the center of Tropical Cyclone Habana was located at latitude 16.1°S and longitude 77.4°E which put it about 695 miles (1120 km) south-southeast of Diego Garcia. Habana was moving toward the east at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 945 mb.

Tropical Cyclone Habana rapidly intensified from the equivalent of a tropical storm to a Category 4 hurricane during the past 24 hours over the South Indian Ocean south of Diego Garcia. A small circular eye with a diameter of 13 miles (20 km) developed at the center of Habana. 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 Tropical Cyclone Habana. Storms near the core generated strong upper level divergence that pumped mass away from the tropical cyclone.

The circulation around Tropical Cyclone Habana was relatively small. Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of Habana. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Habana was 28.3. The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 37.7.

Tropical Cyclone Habana will move through an environment capable of supporting a strong tropical cyclone during the next 36 hours. Habana will move over water where the Sea Surface Temperatures will be near 28°C. It will move near the axis of an upper level ridge over the South Indian Ocean. The winds are weaker near the axis of the ridge and there will be modest vertical wind shear. Tropical Cyclone Habana could remain the equivalent of a major hurricane during the next 36 hours. Since the core of Habana is so small, the inner end of a rainband could wrap around the existing eye and eyewall. In that case an eyewall replacement cycle would cause Tropical Cyclone Habana to weaken

Tropical Cyclone Habana will move south of a high pressure system over the tropical South Indian Ocean during the next 36 hours. The high will steer Habana toward the east during that time period. On its anticipated track Tropical Cyclone Habana will remain far to the south of Diego Garcia. The high pressure system will weaken with time and a second high pressure system located farther to the south will turn Habana back toward the west early next week.

Tropical Cyclone Niran Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Tropical Cyclone Niran rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale over the Coral Sea on Friday morning. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Niran was located at latitude 19.4°S and longitude 160.2°E which put it about 505 miles (815 km) west-northwest of Noumea, New Caledonia. Niran was moving toward the east-southeast at 28 m.p.h. (44 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 922 mb.

Tropical Cyclone Niran continued to intensify rapidly over the Coral Sea on Friday morning even though it was moving quickly toward the east-southeast. A small circular eye with a diameter of 12 miles (19 km) was at the center of Niran. 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 Tropical Cyclone Niran. Storms near the core generated upper level divergence that pumped mass away from the tropical cyclone.

There was a large area of strong winds around Tropical Cyclone Niran. Winds to hurricane/typhoon force extended out 65 miles (105 km) from the center of Niran. Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Niran was 35.0. The Hurricane Size Index (HSI) was 24.3 and the Hurricane Wind Intensity Size Index (HWISI) was 59.3 Niran was capable of causing widespread catastrophic damage.

Tropical Cyclone Niran will move through an environment capable of supporting an intense tropical cyclone during the next 12 hours. Niran will move over water where the Sea Surface Temperatures will be near 29°C. It will move under the axis an upper level ridge over the Coral Sea. The winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Niran could maintain its intensity during the next 12 hours. Niran will begin to weaken when its circulation begins to interact with New Caledonia. An upper level trough near eastern Australia will approach Tropical Cyclone Niran in about 24 hours. The trough will produce northwesterly winds and the wind shear will begin to increase. More shear will cause Niran to start to weaken more quickly on Saturday.

Tropical Cyclone Niran will move around the southwestern part of a high pressure system over the tropical South Pacific Ocean. The high will steer Niran quickly toward the southeast during the next several days. On its anticipated track Tropical Cyclone Niran will begin to affect New Caledonia within 12 hours. Niran will be the equivalent of a major hurricane when it reaches New Caledonia. The track of Tropical Cyclone Niran will cause it to bring very strong winds, a significant storm surge and heavy rain to all of New Caledonia. Tropical Cyclone Niran will be capable of causing widespread catastrophic damage to New Caledonia. Niran could cause a storm surge of up to 16 feet (5 meters) along portions of the coast where the wind blows water toward the shore. It will drop heavy rain and flash floods are likely to occur.

Tropical Cyclone Niran Intensifies to Equivalent of a Major Hurricane

Tropical Cyclone Niran intensified to the equivalent of a major hurricane on Thursday night. At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Niran was located at latitude 17.2°S and longitude 155.6°E which put it about 580 miles (935 km) east of Cairns, Australia. Niran was moving toward the east-southeast at 25 m.p.h. (40 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 946 mb.

Tropical Cyclone Niran intensified to the equivalent of a major hurricane over the Coral Sea west of New Caledonia on Thursday night. A small circular eye with a diameter of 14 miles (22 km) was present at the center of Niran. 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 Tropical Cyclone Niran. Storms around the core generated upper level divergence which pumped mass away from the tropical cyclone.

There was a large area of strong winds around Tropical Cyclone Niran. Winds to hurricane/typhoon force extended out 70 miles (110 km) from the center of Niran. Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation. The Hurricane Intensity Index (HII) for Tropical Cyclone Niran was 23.6. The Hurricane Size Index (HSI) was 25.5 and the Hurricane Wind Intensity Size Index (HWISI) was 49.1. Tropical Cyclone Niran was capable of causing widespread major damage.

Tropical Cyclone Niran will move through an environment favorable for intensification during the next 12 hours. Niran will move over water where the Sea Surface Temperatures will be near 29°C. It will move under the axis an upper level ridge over the Coral Sea. The winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Niran could continue to intensify during the next 12 hours. An upper level trough near eastern Australia will approach Niran in about 24 hours. The trough will produce northwesterly winds and the wind shear will begin to increase. More shear will cause Niran to start to weaken on Saturday.

Tropical Cyclone Niran will move around the southwestern part of a high pressure system over the tropical South Pacific Ocean. The high will steer Niran toward the southeast during the next several days. On its anticipated track Tropical Cyclone Niran could approach New Caledonia in 24 hours. Niran could be the equivalent of a major hurricane when it approaches New Caledonia. Tropical Cyclone Niran will be capable of causing widespread major damage to New Caledonia. Niran will also drop heavy rain and flash floods are likely to occur.