Tag Archives: SH24

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.

Tropical Cyclone Irondro Forms South-southwest of Diego Garcia

Tropical Cyclone Irondro formed south-southwest of Diego Garcia on Thursday.  At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Irondro was located at latitude 13.5°S and longitude 69.9°E which put it about 460 miles (745 km) south-southwest of Diego Garcia.  Irondro was moving toward the southeast at 5 m.p.h. (8 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 1000 mb.

A distinct low level center of circulation developed in an area of thunderstorms over the South Indian Ocean south-southwest of Diego Garcia on Thursday and the system was designated as Tropical Cyclone Irondro.  The circulation around Irondro was still organizing.  Bands of showers and thunderstorms were forming and the bands were beginning to revolve around the center of circulation.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out 145 miles (230 km) from the center of circulation.

Tropical Cyclone Irondro will move through an environment favorable for intensification during the next 48 to 60 hours.  Irondro will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western end of an upper level high over the South Indian Ocean.  The high will produce northwesterly winds which will blow toward the top of the tropical cyclone.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Tropical Cyclone Irondro will intensify and it could strengthen into the equivalent of a hurricane/typhoon.

The upper level high and an upper level trough east of Madagascar will interact to steer Tropical Cyclone Irondro toward the southeast during the next few days.  On its anticipated track Irondro will pass south of Diego Garcia and south of Cocos Island.

Powerful Tropical Cyclone Kenneth Makes Landfall in Northern Mozambique

Powerful Tropical Cyclone Kenneth made landfall in northern Mozambique on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Kenneth was located at latitude 12.1°S and longitude 40.5°E which put it about 60 miles (95 km) north of Pemba, Mozambique.  Kenneth was moving toward the west-southwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 937 mb.

Tropical Cyclone Kenneth continued to intensify until it made landfall near Quissanga, Mozambique.  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 160 miles (260 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Kenneth was 28.2.  The Hurricane Size Index (HSI) was 16.3 and the Hurricane Wind Intensity Size Index (HWISI) was 44.5.  Those indices mean that Tropical Cyclone Kenneth was capable of causing significant regional damage.  In addition to wind damage Kenneth will cause a significant storm surge at the coast.  Locally heavy rain will produce flooding over parts of northern Mozambique.

Tropical Cyclone Kenneth will weaken when it moves inland over northern Mozambique.  However, It will take several days for the circulation around Kenneth to spin down.  The circulation could linger in that area for several days.  If that happens, persistent rainfall will exacerbate flooding of rivers and streams, which would hinder rescue and recovery efforts.

Elsewhere over the southern Indian Ocean, Tropical Cyclone Lorna was swirling well to the east-southeast of Diego Garcia.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Lorna was located at latitude 11.0°S and longitude 86.1°E which put it about 950 miles (1530 km) east-southeast of Diego Garcia.  Lorna was moving toward the east-southeast at 6 m.p.h. (10 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 988 mb.

Major Tropical Cyclone Kenneth Brings Strong Wind, Rain to Comoros

Major Tropical Cyclone Kenneth brought strong wind and rain to the Comoros on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Kenneth was located at latitude 11.3°S and longitude 42.8°E which put it about 35 miles (55 km) north of the Comoros.  Kenneth was moving toward the west at 13 m.p.h. (20 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. (235 km/h).  The minimum surface pressure was 954 mb.

Tropical Cyclone Kenneth intensified rapidly on Tuesday into the equivalent of a major hurricane.  A small circular eye appeared at the center of circulation on infrared 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 the circulation.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone in all directions.

Winds to hurricane/typhoon force extended out about 35 miles (55 km) from the center of Tropical Cyclone Kenneth.  Winds to tropical storm force extended out about 130 miles (215 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Kenneth was 20.1.  The Hurricane Size Index (HSI) was 11.0 and the Hurricane Wind Intensity Size Index (HWISI) was 31.1.  Tropical Cyclone Kenneth was capable of causing major damage.

The southern half of the eyewall of Tropical Cyclone Kenneth passed over northern Grande Comore (Njazidja).  Mitsamiouli and Mbeni were likely to have experienced winds to hurricane/typhoon force.  Strong winds may have also affected the capital, Moroni.  Major wind damage may have occurred in those areas.  Heavy rain falling on steep slopes may cause flash flooding.  Easterly winds blowing up the slopes would have enhanced rainfall and the greatest risks for flooding were on the eastern sides of the mountains.  Those easterly winds may have also generated a significant storms surge along the northeast coast of Grande Comore (Njazidja).

Tropical Cyclone Kenneth will move through an environment very favorable for intensification during the next 12 to 18 hours.  Kenneth will move over water where the Sea Surface Temperature is near 29°C.  It will move under the axis of an upper level ridge where the winds are weak and there will be little vertical wind shear.  Tropical Cyclone Kenneth is likely to intensify more while it moves across the Mozambique Channel.

Tropical Cyclone Kenneth will move north of a subtropical ridge.  The ridge will steer Kenneth a little to the south of due west.  On its anticipated track Tropical Cyclone Kenneth will make landfall on the north coast of Mozambique between Ibo and Mocimboa da Praia in about 18 hours.  Kenneth is likely to be a strong tropical cyclone at the time of landfall.  It will be capable of causing major wind damage and a storm surge at the coast.  Tropical Cyclone Kenneth will also drop heavy rain when it moves inland over northern Mozambique and it could cause additional flooding in that region.

Elsewhere over the South Indian Ocean, Tropical Cyclone Lorna moved gradually farther away from Diego Garcia.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Lorna was located at latitude 10.3°S and longitude 84.8°E which put it about 855 miles (1380 km) east-southeast of Diego Garcia.  Lorna was moving toward the east at 4 m.p.h. (6 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.

Tropical Cyclone Kenneth Develops North of Madagascar

Tropical Cyclone Kenneth developed north of Madagascar on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Kenneth was located at latitude 10.7°S and longitude 47.2°E which put it about 310 miles (500 km) east-northeast of the Comoros.  Kenneth was moving toward the west at 12 m.p.h. (19 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 981 mb.

The circulation around Tropical Cyclone Kenneth organized rapidly on Tuesday.  A band of showers and thunderstorms wrapped around the eastern side of the center of circulation.  Microwave satellite imagery indicated that an eye might be forming at the center of Kenneth.  Other bands of showers and thunderstorms were developing outside the core of the circulation.  Storms around the core were generating upper level divergence which was pumping mass away from the tropical cyclone in all directions.  Winds to tropical storm force extended out about 130 miles (210 km) from the center of circulation.

Tropical Cyclone Kenneth will move through an environment favorable for intensification during the next day or two.  Kenneth will move over water where the Sea Surface Temperature is near 29°C.  It will move under an upper level ridge.  The winds are weak near the core of the ridge and vertical wind shear will be limited as long as Tropical Cyclone Kenneth stays under the central part of the ridge.  Kenneth is likely to intensify into the equivalent of a hurricane/typhoon during the next 12 to 24 hours.  Once an eye forms, Tropical Cyclone Kenneth could intensify rapidly and it could strengthen into the equivalent of a major hurricane.

Tropical Cyclone Kenneth will move north of a subtropical ridge during the next several days.  The ridge will steer Kenneth a little to the south of due west during that time period.  On its anticipated track the core of Tropical Cyclone Kenneth could pass near the Comoros in about 24 hours.  Kenneth could be the equivalent of a major hurricane by that time.  It could cause major wind damage and a significant storm surge at the coast.  Kenneth could also drop heavy rain, which could cause flash flooding along the steeper slopes.   Tropical Cyclone Kenneth could make landfall on the coast of northern Mozambique within 48 hours.

Elsewhere over the South Indian Ocean, Tropical Cyclone Lorna developed east of Diego Garcia on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Lorna was located at latitude 9.7°S and longitude 82.9°E which put it about 715 miles (1155 km) east-southeast of Diego Garcia.  Lorna was moving toward the southeast at 13 m.p.h. (20 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.