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Tropical Cyclone Harold Strengthens to Equivalent of Cat. 5 Hurricane

Tropical Cyclone Harold strengthened to the equivalent of a Category 5 hurricane on Monday.  After weakening while the eye crossed the southern end of Espiritu Santo, the core of Harold rapidly intensified and the tropical cyclone became even more powerful.  At 11:00 a.m. EDT on Monday the center of Tropical Cyclone Harold was located at latitude 16.2°S and longitude 169.4°E which put it about 120 miles (195 km) north-northeast of Port Vila, Vanuatu.  Harold was moving toward the east-southeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 165 m.p.h.  and there were wind gusts to 200 m.p.h. (320 km/h).  The minimum surface pressure was 912 mb.

The inner core of Tropical Cyclone Harold weakened when the eye moved across the southern end of Espiritu Santo.  For a time the eye was less distinct of satellite images.  However, the eye cleared out quickly after it moved back over water and the core of Harold strengthened further.  By Monday a small, well formed eye was evident infrared satellite images.  The eye had a diameter of 12 miles (19 km).  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 Tropical Cyclone Harold.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

Winds to hurricane/typhoon force extended out 40 miles (65 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 190 miles (305 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Tropical Cyclone Harold was 36.8.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 52.8.  Harold was capable of causing catastrophic damage.

The core of Tropical Cyclone Harold passed over the southern end of Espiritu Santo.  It then passed near the northern end of Malekula before battering Pentecost and Ambrym.  Harold likely caused catastrophic wind damage in those locations.  Tropical Cyclone Harold also dropped locally heavy rain over Espiritu Santo, Malekula, Pentecost, Maewo, and Ambrym.  Flash flooding probably occurred on those islands.

Tropical Cyclone Harold will move through an environment capable of support an intense tropical cyclone during the next several days.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  If a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Tropical Cyclone Harold to weaken.  Tropical cyclones generally do not maintain Category 5 intensity for an extended period of time.  So, Tropical Cyclone Harold is likely to start to weaken within 24 hours.

Tropical Cyclone Harold will move around the southwestern part of a high pressure system over the South Pacific Ocean.  The high will steer Harold toward the east-southeast during the next few days.  On its anticipated track Tropical Cyclone Harold will move away from Vanuatu.  Harold could approach Fiji within 36 hours and it could still be the equivalent of a major hurricane at that time.

Tropical Cyclone Harold Batters Espiritu Santo

Tropical Cyclone Harold battered Espiritu Santo on Sunday.  The eye of Harold moved over the southwestern part of Espiritu Santo.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Harold was located at latitude 15.3°S and longitude 166.4°E which put it about 60 miles west-northwest of Luganville, Vanuatu.  Harold was moving toward the east at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 929 mb.

Tropical Cyclone Harold strengthened on Sunday as it slowly approached northern Vanuatu.  A circular eye with a diameter of 18 miles (29 km) was evident on satellite images.  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 Harold.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

Winds to hurricane/typhoon force extended out 45 miles (75 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Tropical Cyclone Harold was 29.9.  The Hurricane Size Index (HSI) was 13.3 and the Hurricane Wind Intensity Size Index (HWISI) 43.2.  Harold was capable of causing significant damage.

Tropical Cyclone Harold will move around the southwestern part of a high pressure system over the South Pacific Ocean.  The high will steer Harold toward the east-southeast during the next few days.  On its anticipated track the center of Tropical Cyclone Harold will move across the southern end of Espiritu Santo.  The center will also pass near the northern end of Malekula, near the southern end of Pentecost and near Ambrym.  Tropical Cyclone Harold will drop heavy rain over Espiritu Santo, Malekula, Pentecost, Ambrym, Epi, Ambae and Maewo.  Harold will move slowly and the heavy rain is likely to cause flash floods.  Strong winds blowing toward the coast could produce significant storm surges on the eastern and northern coasts of some islands.

Tropical Cyclone Harold will move through an environment favorable for a strong tropical cyclone.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  Since the core of Tropical Cyclone Harold will pass over the southern end of Espiritu Santo, increased friction will cause the circulation to weaken during the next 12 to 24 hours.

Major Tropical Cyclone Harold Nears Vanuatu

Major Tropical Cyclone Harold neared Vanuatu on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Cyclone Vanuatu was located at latitude 15.5°S and longitude 166.0°E which put it about 80 miles (130 km) west-northwest of Unmet, Vanuatu.  Harold was moving toward the southeast 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 Harold intensified into the equivalent of a major hurricane.  The original small eye dissipated but a new larger eye developed on Saturday night.  The new eye was surround 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 Harold.  The strongest rainbands were in the eastern and southern parts of the circulation.  Storms near the core of Harold generated upper level divergence which pumped mass away from the center of the tropical cyclone.

Winds to hurricane/typhoon force extended out 30 miles (50 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 125 miles (200 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Harold was 22.1.  The Hurricane Size Index (HSI) was 11.1 and the Hurricane Wind Intensity Size Index (HWISI) was 33.2.  Tropical Cyclone Harold was capable of causing major damage.

Tropical Cyclone Harold will move through an environment favorable for intensification during the next 24 hours.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move around the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear and the wind shear could be strong enough to limit intensification.  Tropical Cyclone Harold could intensify further, but it may maintain its intensity on Sunday.

The ridge over the South Pacific Ocean will steer Tropical Cyclone Harold slowly toward the southeast during the next 24 hours.  On its anticipated track the core of Harold with the strongest winds will move slowly toward Malekula.  Tropical Cyclone Harold will drop heavy rain over central Vanuatu.  The slow movement of Harold could create the potential for very serious flooding on Espiritu Santo, Malekula, Ambrym and Epi.

Elsewhere in the tropics, Tropical Cyclone Irondro began to slowly weaken over the South Indian Ocean.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Irondro was located at latitude 23.3°S and longitude 81.5°E which put it about 1275 miles (2060 km) southwest of Cocos Island.  Irondro was moving toward the southeast at 18 m.p.h. (29 km/h).  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).  The minimum surface pressure was 958 mb.

Tropical Cyclone Harold Rapidly Intensifies into Equivalent of Hurricane/Typhoon

Tropical Cyclone Harold rapidly intensified into the equivalent of a hurricane/typhoon west-northwest of Vanuatu on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Cyclone Harold was located at latitude 14.1°S and longitude 164.1°E which put it about 170 miles (275 km) west-northwest of Nokuku, Vanuatu.  Harold was moving toward the southeast at 5 m.p.h. (8 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. (200 km/h).  The minimum surface pressure was 959 mb.

The circulation around Tropical Cyclone Harold organized quickly on Friday.  The inner end of a rainband wrapped around the center of circulation and a small eye formed.  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 Harold.  The strongest rainbands were in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms around the core of the circulation generated strong upper level divergence which pumped mass away to the east of the tropical cyclone.

Winds to hurricane/typhoon force extend out 35 miles (55 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Tropical Cyclone Harold was 17.8.  The Hurricane Size Index (HSI) was 12.0 and the Hurricane Wind Intensity Size Index (HWISI) was 29.8.  Harold was capable of causing serious damage.

Tropical Cyclone Harold will move through an environment favorable for intensification during the next 24 to 48 hours.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move around the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge 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 Harold will strengthen into the equivalent of a major hurricane during the next 12 hours.

The upper level ridge will steer Tropical Cyclone Harold slowly toward the southeast during the weekend.  On its anticipated track Harold will gradually approach Espiritu Santo and Malekula in Vanuatu.  The core of Tropical Cyclone Harold could move across the central part of Vanuatu in 48 to 72 hours.  Harold is likely to be the equivalent of a major hurricane at that time.

Elsewhere in the tropics, Tropical Cyclone Irondro intensified into the equivalent of a hurricane/typhoon over the South Indian Ocean.  At 5:00 p.m. EDT on Friday the center of Tropical Cyclone Irondro was located at latitude 19.9°S and longitude 76.4°E which put it about 885 miles (1425 km) south-southeast of Diego Garcia.  Irondro was moving toward the east-southeast at 21 m.p.h. (33 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 973 mb.

Strengthening Tropical Cyclone Damien Nears Western Australia

Strengthening Tropical Cyclone Damien neared the coast of Western Australia on Friday.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Damien was located at latitude 19.4°S and longitude 116.6°E which put it about 100 miles (160 km) north-northwest of Karratha, Australia.  Damien was moving toward the south-southwest at 7 m.p.h. (11 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 963 mb.

A Warning was in effect for the portion of the coast of Western Australia from De Grey to Onslow including Dampier, Karratha and Port Hedland.  Initial Flood Warnings were in effect for the Coastal Pilbara Rivers.  A Flood Watch was in effect for the Pilbara and Gascoyne District.

Tropical Cyclone Damien continued to strengthen quickly on Friday.  A circular eye developed at the center of Damien.  A narrow 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 Tropical Cyclone Damien.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Damien 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 115 miles (185 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Damien was 16.5.  The Hurricane Size Index (HSI) was 9.9 and the Hurricane Wind Intensity Size Index (HWISI) was 26.4.  Damien was capable of causing localized serious damage.

Tropical Cyclone Damien will move through an environment favorable for intensification during the next 12 hours.  Damien will move over water where the Sea Surface Temperature is near 30°C.  It will move under the western end of an upper level ridge over Australia.  The ridge will produce northerly 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 Tropical Cyclone Damien from strengthening.  Damien could intensify into the equivalent of a major hurricane before it reaches the coast of Western Australia.

Tropical Cyclone Damien will move around the western end of a high pressure system over Australia.  The high will steer Damien toward the south during the next several days.  On its anticipated track the center of Tropical Cyclone Damien could make landfall on the coast of Western Australia near Dampier and Karratha in about 12 hours.  Damien will be capable of causing serious wind damage.  It will also produce a storm surge of up to 10 feet (3 meters) between Port Hedland and Dampier where the wind blows the water toward the coast.  The highest storm surge will occur near where the center makes landfall.  Tropical Cyclone Damien will also drop locally heavy rain and flash floods could occur in parts of Western Australia.

Tropical Cyclone Tino Brings Wind, Rain to Eastern Fiji

Tropical Cyclone Tino brought wind and rain to eastern Fiji on Friday.  The core of Tino moved east of Vanua Levu but the large circulation around the tropical cyclone brought wind and rain across eastern Fiji.  There were reports of flash floods in some parts of Fiji.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Tino was located at latitude 18.6°S and longitude 176.7°W which put it about 190 miles (305 km) north-northwest of Nuku Alofa, Tonga.  Tino was moving toward the southeast at 27 m.p.h. (45 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 964 mb.

Tropical Cyclone Tino intensified into the equivalent of a hurricane/typhoon as it moved over eastern Fiji.  The inner end of a rainband wrapped around the center of circulation and a possible eye was seen on some infrared satellite images.  The strongest winds were occurring in a ring of thunderstorms around the center of circulation.  Bands of showers and thunderstorms were revolving around the core of the tropical cyclone.  There was a large circulation around Tropical Cyclone Tino.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 400 miles (645 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Tino was 11.5.  The Hurricane Size Index (HSI) was 22.6 and the Hurricane Wind Intensity Size Index (HWISI) was 34.1.  Tropical Cyclone Tino was capable of causing widespread mostly minor damage and smaller areas of more significant damage.

Tropical Cyclone Tino will move through an environment favorable for intensification during the next 12 hours.  Tino will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southwestern portion of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, but the shear will not be strong enough during the next 12 hours to prevent intensification.   The wind speed will increase in about a day or so and more vertical wind shear will cause Tropical Cyclone Tino to weaken when that occurs.

Tropical Cyclone Tino will around the southwestern end of a high pressure system over the South Pacific Ocean.  The high will steer Tino toward the southeast.  On its anticipated track the center of Tropical Cyclone Tino could affect Tonga within 12 hours.  Tino will be the equivalent of a hurricane/typhoon when it moves over Tonga.  It will bring strong winds and rain.  Locally heavy rain could cause flash floods.

Typhoon Phanfone Hits Panay Island

Typhoon Phanfone hit Panay Island on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Typhoon Phanfone was located at latitude 11.9°N and longitude 121.8°E which put it about 50 miles (80 km) southeast of San Jose, Philippines.  Phanfone was moving toward the west at 12 m.p.h. (19 km/h).  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).  The minimum surface pressure was 963 mb.

The eye of Typhoon Phanfone passed over the northern coast of Panay Island on Tuesday.  The southern part of the eyewall affected Roxas City, Kalibo and Ibajay.  Strong winds and heavy rain moved over the northern coast of Panay.  The northern eyewall was over Tablas Island and the northwestern part of the eyewall reached southeastern Mindoro.  Gusty winds may reach Roxas and San Jose on Mindoro.  Heavy rain was falling over over Tablas Island and southeastern Mindoro.

Typhoon Phanfone strengthened slightly even though parts of the eyewall moved over some of the islands in the central Philippines.  The core of Phanfone remained intact and there was a small circular eye at the center of the typhoon.  The strongest winds were occurring in a ring of thunderstorms around the eye.  Winds to typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 125 miles (200 km).  The Hurricane Intensity Index (HII) for Typhoon Phanfone was 19.2.  The Hurricane Size Index (HSI) was 8.3 and the Hurricane Wind Intensity Size Index (HWISI) was 27.5.

Typhoon Phanfone will move through an environment favorable for intensification during the next 24 to 36 hours.  Phanfone 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.  Typhoon Phanfone could intensify into the equivalent of a major hurricane if the core of the circulation passes south of Mindoro.

Typhoon Phanfone will move south of a subtropical high pressure system over the Western North Pacific Island.  The high will steer Phanfone toward the west-northwest during the next several days.  On its anticipated track the center of Typhoon Phanfone will pass near the southern end of Mindoro during the next few hours.  The center will pass near Busuanga Island and Culion Island before Phanfone moves over the South China Sea.  Typhoon Phanfone will bring strong winds and heavy rain to Roxas, San Jose and Coron.  Heavy rain on Tablas Island, southern Mindoro, Busuanga Island and Culion Island could cause flash floods.  Floods are most likely on southern Mindoro because of the steep slopes near mountains.  Conditions will improve over Panay Island as Phanfone moves farther away.

Strengthening Typhoon Phanfone Makes Landfall in Central Philippines

A strengthening Typhoon Phanfone made landfall in the central Philippines on Tuesday morning.  At 10:00 a.m. EST on Tuesday the center of Typhoon Phanfone was located at latitude 11.6°N and longitude 124.1°E which put it about 30 miles (50 km) southeast of Placer, Philippines.  Phanfone was moving toward the west-northwest at 19 m.p.h. (31 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. (200 km/h).  The minimum surface pressure was 966 mb.

Typhoon Phanfone strengthened quickly as it made landfall in the central Philippines.  A small circular eye became more distinct on  satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Winds to typhoon force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 120 miles (195 km) from the center.  The Hurricane intensity Index (HII) for Typhoon Phanfone was 17.8.  The Hurricane Size Index (HSI) was 10.8 and the Hurricane Wind intensity Size Index (HWISI) was 28.6.

The center of Typhoon Phanfone made landfall near Guiuan on Samar.  The center of Phanfone passed near Tacloban on Leyte before it moved over the Visayan Sea.  Typhoon Phanfone brought strong winds and heavy rain to Samar and Leyte.  The winds were strong enough to cause serious damage and regional power outages.  The heavy rain could cause flash floods in some locations.

Typhoon Phanfone moved through a favorable environment that allowed to strengthen.  Phanfone moved over water where the Sea Surface Temperature was near 29°C.  It moved through a region where the upper level winds were weak and there was little vertical wind shear.  The core of Phanfone moved quickly over narrow portions of Samar and Leyte and the core remained intact.  Typhoon Phanfone could strengthen while the enter moves across the Visayan Sea and it could intensify into the equivalent of a major hurricane.

Typhoon Phanfone will move south of a subtropical ridge over the Western North Pacific Ocean during the next several days.  The ridge will steer Phanfone toward the west-northwest.  On its anticipated track the center of Typhoon Phanfone will pass near Masbate and the northern end of Panay Island.  Phanfone could be near Mindoro in about 12 hours.  Typhoon Phanfone will bring strong winds and heavy rain to Masbate, the northern end of Panay Island, the northern end of Negros and Mindoro.  Conditions will improve gradually when Phanfone moves away from Samar and Leyte.

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 Ambali Rapidly Intensifies to Threshold of Cat. 5

Tropical Cyclone Ambali rapidly intensified to the threshold of a Category 5 hurricane on the Saffir-Simpson Scale on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Ambali was located at latitude 10.8°S and longitude 62.1°E which put it about 740 miles (1190 km) north-northeast of Port Louis, Mauritius.  Ambali was moving toward the south-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 932 mb.

Tropical Cyclone Ambali rapidly intensified from a minimal tropical storm to the threshold of a Cat. 5 hurricane in less than 36 hours over the Southwest Indian Ocean.  Nearly perfect environmental conditions including warm water and little vertical wind shear allowed Ambali to strengthen very rapidly.  A small circular eye formed at the center of the tropical cyclone.  The eye was surrounded by 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 Ambali.

The circulation around Tropical Cyclone Ambali was small which also contributed to the rapid intensification.  Winds to hurricane/typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Ambali was 33.3.  The Hurricane Size Index (HSI) was 7.9 and the Hurricane Wind Intensity Size Index (HWISI) was 41.2.

Tropical Cyclone Ambali may be near its maximum intensity, although it could strengthen a little more during the next six to twelve hours.  Ambali will move over water where the Sea Surface Temperature is near 28°C.  It will remain in an area where the upper level winds are weak during the next six to twelve hours and there will be little vertical wind shear during that time.  Tropical Cyclone Ambali will approach an area where there are strong upper level westerly winds during the weekend.  Ambali will weaken when the wind shear increases.

Tropical Cyclone Ambali will move around the western part of a subtropical high pressure over the South Indian Ocean.  The high will steer Ambali toward the south-southwest during the next several days.  On its anticipated track Tropical Cyclone Ambali will move toward Mauritius.

Elsewhere over the Southwest Indian Ocean, Tropical Cyclone Belna was intensifying north of Madagascar.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Belna was located at latitude 7.5°S and longitude 49.0°E which put it about 300 miles (485 km) north of Madagsacar.  Belna was moving toward the southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 982 mb.

The circulation around Tropical Cyclone Belna exhibited much greater organization on Thursday.  An eye appeared to be forming at the center of circulation on microwave satellite images.  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 about the core of Belna.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Tropical Cyclone Belna will move through an environment favorable for intensification during the next 24 to 48 hours.  Belna will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Cyclone Belna is likely to strengthen into the equivalent of a hurricane/typhoon on Friday.  Belna could intensify rapidly once an eye and eyewall are full formed.  It could strengthen into the equivalent of a major hurricane during the weekend.

Tropical Cyclone Belna will move around the western end of a ridge of high pressure over the South Indian Ocean.  The high will steer Belna toward the south-southwest during the next few days.  On its anticipated track Tropical Cyclone Blena could approach the coast of northwestern Madagascar in three or four days.  Belna could be the equivalent of a hurricane/typhoon when it approaches Madagascar.