Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Cyclone Lili Forms Over Timor Sea

Tropical Cyclone Lili formed over the Timor Sea on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Lili was located at latitude 9.1°S and longitude 128.8°E which put it about 100 miles (160 km) southeast of Tutuala, East Timor.  Lili was moving toward the south-southwest at 5 m.p.h. (8 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 991 mb.

The circulation around a low pressure system over the Timor Sea exhibited more organization on Thursday and the system was designated as Tropical Cyclone Lili.  Several bands of showers and thunderstorms began to wrap around the low level center of circulation.  Additional bands of showers and thunderstorms began to develop around the periphery of the circulation.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.   The circulation around Tropical Cyclone Lili was relatively small.  Winds to tropical storm force only extended out about 60 miles (95 km) from the center of circulation.

Tropical Cyclone Lili will move through an environment favorable for intensification during the next 12 to 24 hours.  Lili will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western portion of an upper level ridge.  Tropical Cyclone Lili will move through an area where the upper level winds are not too strong during the next 12 to 24 hours and there will not be a lot of vertical wind shear.  Lili could intensify during that period.  Tropical Cyclone Lili will move closer to the western end of the ridge in about 24 hours.  There are strong northerly winds blowing around the western end of the ridge and there will be more vertical wind shear.  If the shear increases, then the circulation around Lili is likely to weaken.

Tropical Cyclone Lili will move north of a subtropical ridge.  The ridge is likely to steer Lili more toward the west.  On its anticipated track Tropical Cyclone Lili could reach East Timor in about 36 hours.  Lili will bring gusty winds, but heavy rain and flooding are greater risks.  An alternative forecast scenario is possible.  If the vertical wind shear is not too strong and the vertical structure of Tropical Cyclone Lili remains intact, the upper level ridge could steer Lili more toward the south.  In that case Tropical Cyclone Lili could bring rain to Western Australia.

Powerful Tropical Cyclone Fani Makes Landfall in India

Powerful Tropical Cyclone Fani made landfall near Puri, India on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Fani was located at latitude 19.4°N and longitude 85.8°E which put it about 25 miles (40 km) south of Puri, India.  Fani was moving toward the north-northeast at 11 m.p.h. (17 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 922 mb.

Tropical Cyclone Fani is a large dangerous system.  Winds to hurricane/typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 225 miles (360 km) from the center over the Bay of Bengal.  The Hurricane Intensity Index (HII) for Tropical Cyclone Fani is 31.6.  The Hurricane Size Index (HSI) is 25.6 and the Hurricane Wind Intensity Size Index (HWISI) is 57.2.  Tropical Cyclone Fani has the potential to cause widespread significant damage.

Tropical Cyclone Fani will cause the greatest wind damage along the northeast coast of Odisha.  It could also produce a significant storm surge along the coast.  The surge will be highest in bays, estuaries and mouths of rivers.  Fani will drop heavy rain over northeast Odisha, West Bengal and portions of Bangladesh.  The heavy rain is likely to cause inland fresh water floods in some locations.  Wind and rain could cause damage around Kolkata (Calcutta), India.

An upper level trough over India will steer Tropical Cyclone Fani toward the northeast during the next 48 hours.  On its anticipated path Fani will pass near Bhubaneshwar, Cuttack and Baleshwar in Odisha.  Tropical Cyclone Fani could still be the equivalent of a hurricane/typhoon when it passes near those locations.  Fani will weaken steadily while it moves northeast.  It is likely to be the equivalent of a tropical storm when it passes near Kolkata.  Tropical Cyclone Fani will weaken to the equivalent of a tropical depression when it passes over Bangladesh, but it could still drop heavy rain around Dhaka.  Serious flooding could occur in Bangladesh while Fani weakens.

Dangerous Tropical Cyclone Fani Near Northeast India

Dangerous Tropical Cyclone Fani neared the coast of northeastern India on Thursday.  Fani rapidly intensified into the nearly the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  At 11:00 a.m. EDT on Thursday the center of Tropical Cyclone Fani was located at latitude 18.0°N and longitude 84.9°E which put it about 100 miles (160 km) east of Visakhapatnam, India.  Fani was moving toward the north at 11 m.p.h. (17 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 918 mb.

Tropical Cyclone Fani intensified rapidly during recent hours.  A circular eye with a diameter of 20 miles (32 km) developed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Fani.  Storms near the core were generating strong upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Fani grew larger as it intensified.  Winds to hurricane/typhoon force extended out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Fani was 33.3.  The Hurricane Size Index (HSI) was 21.7 and the Hurricane Wind Intensity Size Index (HWISI) was 55.0.  Tropical Cyclone Fani was capable of causing widespread significant damage.

Tropical Cyclone Fani is moving around the western end of a subtropical ridge.  The ridge is steering Fani toward the north.  On its anticipated track Tropical Cyclone Fani is likely to make landfall near Brahmapur, India in about 12 hours.  An upper level trough over India will steer Fani toward the northeast after it makes landfall.  Tropical Cyclone Fani could pass near Puri, Bhubaneswar, Cuttack and Kolkata (Calcutta), India.

Tropical Cyclone Fani will remain in a favorable environment during the 12 hours prior to landfall.  Fani will be 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.  Tropical Cyclone Fani will weaken after landfall.  The upper level trough over India will produce stronger southwesterly winds, which will increase the vertical wind shear after Fani makes landfall.  More wind shear and more friction over the land will cause Tropical Cyclone Fani to weaken to the equivalent of a tropical storm within 24 hours after landfall occurs.

Tropical Cyclone Fani is a dangerous tropical cyclone.  The strengthen and size of Fani will create the potential for widespread significant damage.  The counterclockwise circulation will cause the winds to blow water toward the coast along the northern Bay of Bengal.  Tropical Cyclone Fani could generate a storm surge of 15 to 20 feet (4.5 to 6.0 meters) in bays, estuaries and the mouths of rivers which act as funnels during storm surges.  Heavy rain could cause inland fresh water flooding in parts of northeastern India and Bangladesh.  The greatest threats are to the Indian states of Odisha (Orissa) and West Bengal.

Tropical Cyclone Fani Strengthens to Equivalent of Major Hurricane

Tropical Cyclone Fani strengthened to the equivalent of a major hurricane on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Fani was located at latitude 14.1°N and longitude 83.9°E which put it about 670 miles (1080 km) south-southwest of Kolkata (Calcutta), India.  Fani was moving toward the northwest 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 946 mb.

Tropical Cyclone Fani strengthened on Tuesday.  A small eye emerged at the center of circulation.  The eye was surround by a ring of thunderstorms.  The storms were stronger in the western half of the ring and that was where the strongest winds were.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Fani.  The stronger bands were south and west of the center of Fani.  It appeared that a little drier air may have been pulled into the northern half of the circulation and the bands were weaker in that part of the circulation.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Fani had a moderately sized circulation.  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 Fani was 22.1.  The Hurricane Size Index (HSI) was 14.7 and the Hurricane Wind Intensity Size Index (HWISI) was 36.8.

Tropical Cyclone Fani will remain in an environment favorable for strong tropical cyclones during the next 24 to 36 hours.  Fani will move over water where the Sea Surface Temperature is near 30°C.  It will move near the western end of an upper level ridge and the upper level winds will not be too strong.  The major inhibiting factor will be the drier air over the northern half of the circulation.  Tropical Cyclone Fani could maintain its intensity and even strengthen during the next 24 hours if the drier air moistens over the warm water of the Bay of Bengal.

Tropical Cyclone Fani will move around the western end of a subtropical ridge on Wednesday.  Fani will move more toward the north when it rounds the end of the ridge.  An upper level trough approaching India from the west will turn Tropical Cyclone Fani toward the northeast in about 18 to 24 hours.  On its anticipated track Fani could approach the coast of Orissa state southwest of Kolkata in about 48 hours.  Tropical Cyclone Fani could bring strong winds to parts of Orissa and West Bengal.  Fani could also cause a significant storm surge along portions of the coast around the northern Bay of Bengal.  Locally heavy rain could also cause floods in Orissa and West Bengal.

Tropical Cyclone Fani Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Fani strengthened to the equivalent of a hurricane/typhoon over the Bay of Bengal on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone Fani was located at latitude 11.4°N and longitude 86.9°E which put it about 800 miles (1290 km) south of Kolkata (Calcutta), India.  Fani was moving toward the north at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 974 mb.

The circulation around Tropical Cyclone Fani exhibited greater organization on Monday.  The inner end of a rainband wrapped most of the way around the eastern and northern sides of the center of circulation.  Although there was still a break on the southwestern side of the center, an eye may have been forming at the center of circulation.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Fani and the circulation was much more symmetrical.  Storm around the core were generating upper level divergence which was pumping mass away from the tropical cyclone.  Winds to tropical storm force extended out about 140 miles (225 km) from the center of circulation.

Tropical Cyclone Fani will move through an environment favorable for intensification during the next several days.  Fani will move over water where the Sea Surface Temperature is near 31°C.  It will move under the axis of an upper level ridge where the winds are weak.  Very warm water and little vertical wind shear will allow Tropical Cyclone Fani to intensify during the next 48 hours.  It could intensify rapidly once the inner core is fully developed.  Fani is likely to strengthen into the equivalent of a major hurricane during the next  2 to 3 days.

Tropical Cyclone Fani will move around the western end of a subtropical ridge during the next few days.  The ridge will steer Fani in a generally northward direction.  On its anticipated track Tropical Cyclone Fani could approach the coast of India southwest of Kolkata in three or four days.  Fani could be the equivalent of a major hurricane when it approaches the coast.  Tropical Cyclone Fani has the potential to cause major wind damage.  It will also generate a dangerous storm surge along the coast.  Heavy rain will create the potential for fresh water flooding in inland locations.  The greatest risks at this time are for the Indian states of Orissa and West Bengal.

Tropical Cyclone Fani Develops East of Sri Lanka

Tropical Cyclone Fani developed over the southern Bay of Bengal east of Sri Lanka on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Cyclone Fani was located at latitude 7.8°N and longitude 88.6°E which put it about 635 miles (1020 km) east-southeast of Chennai, India.  Fani was moving toward the north-northwest at 15 m.p.h. (24 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 989 mb.

A distinct low level center of circulation formed on the eastern side of a cluster of thunderstorms over the southern Bay of Bengal on Saturday and the India Meteorological Department designated the system as Tropical Cyclone Fani.  The circulation around Fani was still organizing.  Bands of showers and thunderstorms were developing.  Many of the stronger thunderstorms were developing in two clusters which were east and northwest of the center of circulation.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone Fani will move into an environment that is more favorable for intensification.  Fani is currently under the southern part of an upper level ridge.  The ridge is producing easterly winds which are causing moderate vertical wind shear.  The wind shear is the primary factor slowing the intensification of Tropical Cyclone Fani.  Fani is forecast to move under the axis of the ridge where the upper level winds are weaker.  There will be less vertical wind shear when that happens.  Tropical Cyclone Fani will move over water where the Sea Surface Temperature is near 31°C.  So, intensification is very likely when the wind shear decreases.  Fani is likely to strengthen into the equivalent of a hurricane/typhoon.  Rapid intensification could occur if the inner core of the circulation becomes more well developed.

Tropical Cyclone Fani will move around the western end of a subtropical ridge over southeast Asia.  The ridge will steer Fani toward the north-northwest during the next several days.  It will move more toward the north when it moves around the western end of the ridge.  On its anticipated track Tropical Cyclone Fani will move toward the northern Bay of Bengal.

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.

NHC Upgrades Hurricane Michael to Cat. 5

The National Hurricane Center (NHC) upgraded Hurricane Michael to Category 5 on the Saffir-Simpson Scale after it completed and released its post storm analysis on Friday.  NHC does a post storm analysis of every tropical cyclone in its area of responsibility after the end of the hurricane season.  The maximum sustained wind speed at the time of landfall in northwest Florida of Hurricane Michael, which was given originally as 155 m.p.h. (250 km/h), was increased to 160 m.p.h. (260 km/h) after the post storm analysis.  Hurricane Michael becomes one of only four hurricanes to make landfall in the U.S. as a Category 5 hurricane.  The other Category 5 hurricanes to hit the U.S. were the Labor Day Hurricane which hit the Florida Keys in 1935, Hurricane Camille which hit Mississippi in 1969 and Hurricane Andrew which hit south Florida in 1992.

The National Hurricane Center prepares a Tropical Storm Report on every tropical cyclone in its area of responsibility and those reports are available on NHC’s web site.  J. L. Beven II, R. Berg and A. Hagen were the authors of the Tropical Cyclone Report on Hurricane Michael.  They explain in the Tropical Cyclone Report how they arrived at the intensity of Hurricane Michael at landfall.  They analyzed aircraft data including flight level winds and SMFR intensities.  They did an analysis of the Dopper wind velocities observed by the WSR-88D radar at Eglin Air Force Base.  They also considered available data on the surface winds and pressures and satellite derived estimates of the intensity of Hurricane Michael.  Based on analysis of all of that information, they concluded that the intensity of Hurricane Michael when it made landfall in northwest Florida was 160 m.p.h. (260 km/h).  Their full Tropical Cyclone Report on Hurricane Michael is available on NHC’s website at https://www.nhc.noaa.gov/data/tcr/AL142018_Michael.pdf.