Tag Archives: HWISI

Hurricane Melissa Brings Wind and Rain to the Bahamas

Hurricane Melissa was bringing wind and rain to the Bahamas on Wednesday afternoon.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Melissa was located at latitude 22.9°N and longitude 74.8°W which put the center about 20 miles (30 km) southeast of Clarence Town, Bahamas.  Melissa was moving toward the northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 974 mb.

Hurricane Warnings are in effect for the Central Bahamas and the Southeastern Bahamas.

A Hurricane Watch is in effect for Bermuda.

Tropical Storm Warnings are in effect for the Turks and Caicos.

The circulation around Hurricane Melissa showed signs of reorganization on Friday afternoon.  However, passage over Jamaica and eastern Cuba significant changed the structure of the core of Melissa’s circulation.  A new large eye with a diameter of 45 miles (75 km) formed at the center of Hurricane Melissa.  New thunderstorms were developing in a broken ring that surrounded the large eye.  The strongest winds were occurring in that broken ring of storms.  New thunderstorms were also forming in the bands revolving around the center of Melissa’s circulation.

The structural changes in the middle of Hurricane Melissa caused the size of the circulation to increase.  Winds to hurricane force extended out 60 miles (95 km) in the eastern side of Melissa’s circulation.  Winds to hurricane force extended out 25 miles (40 km) in the western side of Hurricane Melissa.  Winds to tropical storm force extended out 185 miles (300 km) in the eastern half of Melissa’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) in the western half of Hurricane Melissa.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 13.9.  The Hurricane Size Index (HSI) is 16.6 and the Hurricane Wind Intensity Size Index (HWISI) is 30.5.  Hurricane Melissa is similar in intensity to Hurricane Beryl when Beryl hit Texas in 2024.  Melissa is much larger than Beryl was.

Hurricane Melissa will move through an environment marginally favorable for intensification during the next 12 hours.  Melissa will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southeastern part of an upper level trough over the eastern U.S.  The upper level trough will produce southwesterly winds that will blow toward the top of Melissa’s circulation.  Those winds will cause the vertical wind shear to increase. The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Hurricane Melissa could intensify during the next 12 hours.  The upper level winds will get stronger on Thursday.  More vertical wind shear will cause Hurricane Melissa to weaken.  The stronger wind shear will also cause Melissa to start a transition to an extratropical cyclone.

The upper level trough will steer Hurricane Melissa toward the northeast during the next 24 hours.  On its anticipated track, Melissa will continue to move over the Bahamas during the next few hours.  Hurricane Melissa will be near Bermuda on Thursday night.

Hurricane Melissa will continue to bring strong winds and heavy rain to the Central and Southeastern Bahamas on Wednesday night.  Melissa could bring strong winds and heavy rain to Bermuda on Thursday night.

Hurricane Melissa Batters Eastern Cuba

Strong winds in Hurricane Melissa battered eastern Cuba early on Wednesday.  At 8:00 a.m. EDT on Wednesday the center of Hurricane Melissa was located at latitude 20.6°N and longitude 75.7°W which put the center about 45 miles (75 km) northwest of Guantanamo, Cuba.  Melissa was moving toward the north-northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 968 mb.

Hurricane Warnings are in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, Holguin, and Las Tunas.

Hurricane Warnings are in effect for the Central Bahamas and the Southeastern Bahamas.

A Hurricane Watch is in effect for Bermuda.

A Tropical Storm Warning is in effect for Haiti.

A Tropical Storm Warning is in effect for the Cuban province of Camaguey.

A Tropical Storm Warning is in effect for the Turks and Caicos.

After leaving a trail of destruction in Jamaica, Hurricane Melissa battered eastern Cuba early on Wednesday.  Melissa was still a major hurricane at the time is made the center of circulation landfall in the province of Santiago de Cuba.  Melissa started to weaken slowly again after the center moved over land.

Hurricane Melissa was still a powerful storm on Wednesday morning.  Winds to hurricane force extended out 30 miles (50 km) from the center of Melissa’s circulation.  Winds to tropical storm force extended out 185 miles (300 km) in the eastern half of Melissa’s circulation.  Winds to tropical storm force extended out 105 miles (165 km) in the western side of Hurricane Melissa.

The Hurricane Intensity Index (HII) for Hurricane Melissa at the time of landfall was 17.8.  The Hurricane Size Index (HSI) was 11.9 and the Hurricane Wind Intensity Size Index (HWISI) was 29.7. Hurricane Melissa was similar in size and intensity to Hurricane Sally when Sally hit South Alabama in 2020.

Hurricane Melissa will move through an environment marginally favorable for intensification during the next 24 hours.  Melissa will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southeastern part of an upper level trough over the eastern U.S.  The upper level trough will produce southwesterly winds that will blow toward the top of Melissa’s circulation.  Those winds will cause the vertical wind shear to increase.  The vertical wind shear will inhibit intensification.  Hurricane Melissa is likely to maintain its intensity during the next 24 hours after it moves northeast of Cuba.

The upper level trough will steer Hurricane Melissa toward the northeast during the next 24 hours.  On its anticipated track, Melissa will move northeast of Cuba during the next few hours.  Hurricane Melissa will move over the Bahamas later today.  Melissa will be near Bermuda on Thursday night.

Hurricane Melissa will continue to bring strong winds and heavy rain to eastern Cuba during the next few hours.  Heavy rain is likely to cause flash floods in some location.  Widespread electricity outages are likely in eastern Cuba.  Melissa will also bring strong winds and heavy rain to the Bahamas later today.

Hurricane Melissa Hits Jamaica

Hurricane Melissa hit Jamaica on Tuesday.  At 2:00 p.m. EDT on Tuesday the center of Hurricane Melissa was located at latitude 18.2°N and longitude 78.0°W which put the center about 20 miles 305 km) south-southwest of Montego Bay, Jamaica.  Melissa was moving toward the north-northeast at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 165 m.p.h. (265 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 899 mb.

A Hurricane Warning is in effect for Jamaica.

Hurricane Warnings are in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, Holguin, and Las Tunas.

Hurricane Warnings are in effect for the Central Bahamas and the Southeastern Bahamas.

A Tropical Storm Warning is in effect for Haiti.

A Tropical Storm Warning is in effect for the Cuban province of Camaguey.

A Tropical Storm Warning is in effect for the Turks and Caicos.

Hurricane Melissa was at Category 5 on the Saffir-Simpson Scale at the time of landfall.  The maximum sustained wind speed was 185 m.p.h. (300 km/h).  The minimum surface pressure was 892 mb.

The Hurricane Intensity Index (HII) for Hurricane Melissa at the time of landfall was 44.1.  The Hurricane Size Index (HSI) was 11.4 and the Hurricane Wind Intensity Size Index (HWISI) was 55.5.  Hurricane Melissa was similar in size and intensity to Hurricane Dorian when Dorian hit the Bahamas in 2019.

Hurricane Melissa was still a Category 5 hurricane on Tuesday afternoon.  A circular eye with a diameter of 17 miles (28 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass in the upper levels was nearly balanced by a strong inflow of mass in the lower levels of the atmosphere.  The near balance of inflow and outflow of mass caused the surface pressure to remain nearly very low during the past few hours.

Winds to hurricane force extended out 30 miles (50 km) from the center of Hurricane Melissa.  Winds to tropical storm force extended out 195 miles (315 km) in the eastern half of Melissa’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Hurricane Melissa.

An upper level trough over the southeastern U.S. will steer Hurricane Melissa toward the northeast during the next 24 hours.  On its anticipated track, the core of Hurricane Melissa will l move northeast across Jamaica.  Melissa will reach eastern Cuba early on Wednesday.  Hurricane Melissa will be over the Bahamas on Wednesday evening.

Hurricane Melissa will drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic.  Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Melissa will be capable of causing severe damage.  Widespread electricity outages are likely.  Infrastructure and transportation are likely to be severely damaged.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba, the Central and Southeastern Bahamas, and the Turks and Caicos.  Heavy rain is likely to cause flash floods in some locations.  Widespread electricity outages are also likely in eastern Cuba.

Hurricane Melissa Nears Jamaica

The core of Hurricane Melissa was nearing southwestern Jamaica on Tuesday morning.  At 10:00 a.m. EDT on Tuesday the center of Hurricane Melissa was located at latitude 17.7°N and longitude 78.1°W which put the center about 45 miles (75 km) south-southeast of Negril, Jamaica.  Melissa was moving toward the north-northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 185 m.p.h. (300 km/h) and there were wind gusts to 220 m.p.h. (355 km/h).  The minimum surface pressure was 892 mb.

A Hurricane Warning is in effect for Jamaica.

Hurricane Warnings are in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

Hurricane Warnings are in effect for the Central Bahamas and the Southeastern Bahamas.

A Hurricane Watch is in effect for the Turks and Caicos.

A Tropical Storm Warning is in effect for Haiti.

A Tropical Storm Warning is in effect for the Cuban province of Las Tunas.

A Tropical Storm Warning is in effect for the Turks and Caicos.

Winds to tropical storm force were already occurring in Jamaica even though the core of Hurricane Melissa was still southwest of Jamaica.  A weather station at the Norman Manley International Airport in Kingston reported a sustained wind speed of 43 m.p.h. (69 km/h) and a wind gust of 59 m.p.h. (93 km/h).  A weather station at the Sangster International Airport in Montego Bay reported a sustained wind speed of 38 m.p.h. (61 km/h) and a wind gust of 54 m.p.h. (87 km/h).  Heavy rain was already falling over parts of Jamaica.

The core of dangerous Hurricane Melissa was nearing the coast of southwestern Jamaica on Tuesday morning.  A circular eye with a diameter of 12 miles (19 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass in the upper levels was nearly balanced by a strong inflow of mass in the lower levels of the atmosphere.  The near balance of inflow and outflow of mass caused the surface pressure to remain nearly steady during the past few hours.

Winds to hurricane force extended out 30 miles (50 km) from the center of Hurricane Melissa.   Winds to tropical storm force extended out 195 miles (315 km) in the eastern half of Melissa’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Hurricane Melissa.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 44.1.  The Hurricane Size index (HSI) is 11.4 and the Hurricane Wind Intensity Size Index (HWISI) is 55.5.  Hurricane Melissa is similar in size and intensity to Hurricane Dorian when Dorian hit the Bahamas in 2019.

Hurricane Melissa will move through an environment favorable for a very powerful hurricane during the few hours until it makes landfall in Jamaica.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Melissa is likely to maintain its intensity until it makes landfall in Jamaica unless an eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall, then the formation of concentric eyewalls would cause Melissa to start to weaken.

An upper level trough over the southeastern U.S. will steer Hurricane Melissa toward the northeast during the next 24 hours.  On its anticipated track, the core of Hurricane Melissa will reach southwestern Jamaica on Tuesday morning.  Melissa will move northeast across Jamaica during much of Tuesday.  Hurricane Melissa will reach eastern Cuba early on Wednesday.

Hurricane Melissa will drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic.  Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Melissa will be capable of causing severe damage.  Widespread electricity outages are likely.  Infrastructure and transportation are likely to be severely damaged.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba, the Central and Southeastern Bahamas, and the Turks and Caicos.  Heavy rain is likely to cause flash floods in some locations.  Widespread electricity outages are also likely in eastern Cuba.

Hurricane Melissa Turns Toward Jamaica

Hurricane Melissa started to make a slow turn toward Jamaica on Monday evening.  At 11:00 p.m. EDT on Monday the center of Hurricane Melissa was located at latitude 16.6°N and longitude 78.5°W which put the center about 150 miles (240 km) southwest of Kingston, Jamaica.  Melissa was moving toward the north-northeast at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 175 m.p.h. (285 km/h) and there were wind gusts to 205 m.p.h. (330 km/h).  The minimum surface pressure was 903 mb.

A Hurricane Warning is in effect for Jamaica.

Hurricane Warnings are in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

Hurricane Warnings are in effect for the Central Bahamas and the Southeastern Bahamas.

A Hurricane Watch is in effect for the Turks and Caicos.

A Tropical Storm Warning is in effect for Haiti.

A Tropical Storm Warning is in effect for the Cuban province of Las Tunas.

A Tropical Storm Warning is in effect for the Turks and Caicos.

Powerful Hurricane Melissa started a slow turn toward Jamaica on Monday evening.  A circular eye with a diameter of 12 miles (19 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass in the upper levels was nearly balanced by a strong inflow of mass in the lower levels of the atmosphere.  The near balance of inflow and outflow of mass caused the surface pressure to remain nearly steady during the past few hours.

Winds to hurricane force extended out 30 miles (50 km) from the center of Melissa’s circulation.  Winds to tropical storm force extended out 195 miles (315 km) in the eastern half of Hurricane Melissa.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Melissa’s circulation.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 40.4.  The Hurricane Size index (HSI) is 11.4 and the Hurricane Wind Intensity Size Index (HWISI) is 51.8.  Hurricane Melissa is similar in size and intensity to Hurricane Andrew when Andrew was at its peak intensity in 1992.

Hurricane Melissa will move through an environment favorable for a very powerful hurricane during the next 12 hours.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Melissa is likely to maintain its intensity during the next 12 hours unless an eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall, then the formation of concentric eyewalls would cause Melissa to weaken.

An upper level trough over the southeastern U.S. will start to steer Hurricane Melissa toward the northeast during the next 24 hours.  On its anticipated track, the core of Hurricane Melissa will reach southwestern Jamaica on Tuesday morning.  Melissa will move northeast across Jamaica during much of Tuesday.  Hurricane Melissa will reach eastern Cuba early on Wednesday.

Hurricane Melissa will drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic.  Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Melissa will be capable of causing severe damage.  Widespread electricity outages are likely.  Infrastructure and transportation are likely to be severely affected.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba, the Central and Southeastern Bahamas, and the Turks and Caicos.  Heavy rain is likely to cause flash floods in some locations.  Widespread electricity outages are also likely in eastern Cuba.

Hurricane Melissa Intensifies to Cat. 5

Hurricane Melissa intensified to Category 5 on the Saffir-Simpson Scale early on Monday.  At 8:00 a.m. EDT on Monday the center of Hurricane Melissa was located at latitude 16.4°N and longitude 78.0°W which put the center about 135 miles (220 km) southwest of Kingston, Jamaica.  Melissa was moving toward the west at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 913 mb.

A Hurricane Warning is in effect for Jamaica.

Hurricane Warnings are in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

Hurricane Watches are in effect for the Central Bahamas, the Southeastern Bahamas, and the Turks and Caicos.

A Tropical Storm Warning is in effect for Haiti.

A Tropical Storm Warning is in effect for the Cuban province of Las Tunas.

Hurricane Melissa intensified to Category 5 on the Saffir-Simpson Scale early on Monday.  A circular eye with a diameter of 12 miles (19 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated strong upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

Winds to hurricane force extended out 30 miles (50 km) from the center of Melissa’s circulation.  Winds to tropical storm force extended out 195 miles (315 km) in the eastern half of Hurricane Melissa.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Melissa’s circulation.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 35.0.  The Hurricane Size index (HSI) is 11.4 and the Hurricane Wind Intensity Size Index (HWISI) is 46.4.  Hurricane Melissa is similar in size and intensity to Hurricane Andrew when Andrew made landfall in South Florida in 1992.

Hurricane Melissa will move through an environment favorable for a very powerful hurricane during the next 24 hours.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Melissa could intensify during the next 24 hours unless an eyewall replacement cycle occur.  If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could cause Melissa to weaken.

The high pressure system that has been steering Hurricane Melissa slowly toward the west is likely to weaken during the next 24 hours.  When the high pressure system weakens, Melissa will start to move slowly toward the north.  On its anticipated track, the core of Hurricane Melissa will hit Jamaica early on Tuesday.

Hurricane Melissa will drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic.  Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Melissa will be capable of causing severe damage.  Widespread electricity outages are likely.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba, the Central and Southeastern Bahamas, and the Turks and Caicos.

Hurricane Melissa Strengthens to Cat. 4

Hurricane Melissa strengthened to Category 4 on the Saffir-Simpson Scale south of Jamaica early on Sunday morning.  At 8:00 a.m. EDT on Sunday the center of Hurricane Melissa was located at latitude 16.3°N and longitude 76.4°W which put the center about 120 miles (195 km) south-southeast of Kingston, Jamaica.  Melissa was moving toward the west at 5 m.p.h. (8 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. (265 km/h).  The minimum surface pressure was 952 mb.

A Hurricane Warning is in effect for Jamaica.

A Hurricane Watch is in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

A Hurricane Watch is in effect for the southern coast of Haiti from the border with the Dominican Republic to Port Au Prince.

A Tropical Storm Warning is also in effect for the southern coast of Haiti from the border with the Dominican Republic to Port Au Prince.

Hurricane Melissa strengthened to Category 4 on the Saffir-Simpson Scale early on Sunday morning.  A circular eye with a diameter of 20 miles (32 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Hurricane Melissa was relatively small.  Winds to hurricane force extended out 25 miles (40 km) from the center of Melissa’s circulation.  Winds to tropical storm force extended out 170 miles (280 km) in the eastern half of Hurricane Melissa.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Melissa’s circulation.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 28.3.  The Hurricane Size index (HSI) is 9.3 and the Hurricane Wind Intensity Size Index (HWISI) is 37.6.  Hurricane Melissa is similar in size and intensity to Hurricane Charley when Charley made landfall in Southwest Florida in 2004.

Hurricane Melissa will move through an environment that will be favorable for intensification during the next 24 hours.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Melissa will intensify during the next 24 hours. Melissa could intensify rapidly at times.  Melissa could strengthen to category 5 on the Saffir-Simpson Scale.

Hurricane Melissa will move around the southern side of a high pressure system that is north of Cuba.  The high pressure system will steer Melissa slowly toward the west during the next 24 hours.  On its anticipated track, Hurricane Melissa will move slowly south of Jamaica on Sunday.  The high pressure system will weaken on Monday and Melissa will move toward Jamaica

Hurricane Melissa is likely to drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic.  Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Melissa will be capable of causing severe damage.  Widespread electricity outages are likely.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba early next week.

Melissa Rapidly Intensifies to a Major Hurricane

Hurricane Melissa rapidly intensified to a major hurricane southeast of Jamaica on Saturday evening.  At 11:00 p.m. EDT on Saturday the center of Hurricane Melissa was located at latitude 16.4°N and longitude 75.9°W which put the center about 115 miles (185 km) south-southeast of Kingston, Jamaica.  Melissa was moving toward the west at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (215 km/h).  The minimum surface pressure was 967 mb.

A Hurricane Warning is in effect for Jamaica.

A Hurricane Watch is in effect for the Cuban provinces of Granma, Santiago de Cuba, Guantanamo, and Holguin.

A Hurricane Watch is in effect for the southern coast of Haiti from the border with the Dominican Republic to Port Au Prince.

A Tropical Storm Warning is also in effect for the southern coast of Haiti from the border with the Dominican Republic to Port Au Prince.

Hurricane Melissa rapidly intensified to a major hurricane on Saturday evening.  A circular eye with a diameter of 20 miles (32 km) was at the center of Melissa’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Melissa.  Storms near the center of Melissa generated upper level divergence that pumped large quantities of mass away from the hurricane.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Hurricane Melissa increased on Saturday.  Winds to hurricane force extended out 25 miles (40 km) from the center of Melissa’s circulation.  Winds to tropical storm force extended out 160 miles (260 km) in the eastern half of Hurricane Melissa.  Winds to tropical storm force extended out 90 miles (145 km) in the western side of Melissa’s circulation.

The Hurricane Intensity Index (HII) for Hurricane Melissa is 20.6.  The Hurricane Size index (HSI) is 9.3 and the Hurricane Wind Intensity Size Index (HWISI) is 29.9.

Hurricane Melissa will move through an environment that will be favorable for intensification during the next 24 hours.  Melissa will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Melissa will intensify during the next 24 hours.  Melissa is likely to continue to intensify rapidly during the next few hours.  Melissa could strengthen to category 5 on the Saffir-Simpson Scale.

Hurricane Melissa will move around the southern side of a high pressure system that is north of Cuba.  The high pressure system will steer Melissa slowly toward the west during the next 24 hours.  On its anticipated track, Hurricane Melissa will move slowly south of Jamaica on Sunday.  The high pressure system will weaken on Monday and Melissa will move toward Jamaica

Hurricane Melissa is likely to drop very heavy rain on Jamaica, Haiti and parts of the Dominican Republic. Very heavy rain is likely to cause catastrophic floods in some locations.  Hurricane Melissa will also produce very strong winds in Jamaica.  Widespread electricity outages are likely.  Melissa could produce a storm surge of up to 16 feet (5 meters) along the south coast of Jamaica.

Hurricane Melissa will also bring strong winds and locally heavy rain to eastern Cuba early next week.

Typhoon Halong Passes South of Tokyo

Typhoon Halong passed south of Tokyo on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Halong was located at latitude 32.8°N and longitude 140.3°E which put the center about 195 miles (315 km) south of Tokyo, Japan.  Halong was moving toward the northeast at 15 m.p.h. (24 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.

Typhoon Halong was starting to weaken as it passed south of Tokyo on Wednesday.  A circular eye with a diameter of 25 miles (40 km) was still present at the center of Halong’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Halong.  Storms near the center of Halong generated upper level divergence that pumped mass away to the east of the typhoon.  The removal of mass was less than the inflow of mass in the lower levels of the atmosphere.  So, the surface pressure was increasing.

The circulation around Typhoon Halong increased in size on Wednesday.  Winds to typhoon force extended out 40 miles (65 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Halong.

The Hurricane Intensity Index (HII) for Typhoon Halong was 23.6.  The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 37.5.  Typhoon Halong was similar in intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.  Halong is bigger than Dennis was.

Typhoon Halong will move through an environment that will become more unfavorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the southern extent of the upper level westerly winds in the middle latitudes.  The upper level westerly winds will blow toward the top of Halong’s circulation.  Those winds will cause the vertical wind shear to increase.  Cooler Sea Surface Temperatures and more vertical wind shear will cause Typhoon Halong to weaken during the next 24 hours.  Halong is likely to make a transition to an extratropical cyclone during the next few days.

The upper level westerly winds will steer Typhoon Halong quickly toward the east during the next 24 hours.  On its anticipated track, Typhoon Halong will move away from Japan on Thursday.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri former southwest of Iwo To.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Nakri was located at latitude 22.3°N and longitude 136.0°E which put the center about 625 miles (1010 km) south-southeast of Okinawa.  Nakri was moving toward the northwest at 18 m.p.h. (30 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 1000 mb.

Hurricane Priscilla Starts to Weaken

Hurricane Priscilla started to weaken on Tuesday evening.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Priscilla was located at latitude 20.6°N and longitude 111.5°W which put the center about 190 miles (305 km) south-southwest of the southern tip of Baja California.  Priscilla was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 962 mb.

A Tropical Storm Watch was in effect for the portion of the coast from Cabo San Lucas to Cabo San Lazaro, Mexico.

Hurricane Priscilla started to weaken on Tuesday evening after Priscilla had strengthened to Category 2 on the Saffir-Simpson Scale earlier in the day.  Hurricane Priscilla appeared to have mixed cooler water to the surface of the Eastern North Pacific Ocean.  A large eye with a diameter of 50 miles (80 km) was still present at the center of Priscilla’s circulation.  However, the ring of thunderstorms surrounding the eye was broken in several places.  Also, many of the thunderstorms in bands in the eastern side of Hurricane Priscilla had weakened.  The bands in the eastern part of Priscilla’s circulation consisted primarily of showers and lower clouds.  Thunderstorms were still occurring in bands in the western half of Hurricane Priscilla.

The circulation around Hurricane Priscilla was still large.  Winds to hurricane force extended out 45 miles (75 km) from the center of Priscilla’s circulation.  Winds to tropical storm force extended out 195 miles (315 km) from the center of Hurricane Priscilla.

The Hurricane Intensity Index (HII) for Hurricane Priscilla was 17.8.  The Hurricane Size Index (HSI) was 17.1 and the Hurricane Wind Intensity Size Index (HWISI) was 34.9.

Hurricane Priscilla will move through an environment that will become more unfavorable for intensification during the next 24 hours.  An upper level trough near the west coast of the U.S. will start to produce southwesterly winds that will blow toward the top of Priscilla’s circulation.  Those winds will cause the vertical wind shear to begin to increase.  In addition, the cooler water mixed to the surface of the ocean by Priscilla’s winds will limit the energy transfer from the ocean to the atmosphere.  The effects of cooler water and increasing vertical wind shear will cause Hurricane Priscilla to weaken during the next 24 hours.

Hurricane Priscilla will move around the western end of a high pressure system over Mexico.  The high pressure system will steer Priscilla toward the north-northwest during the next 24 hours.  On its anticipated track, Hurricane Priscilla will move parallel to the coast of southwestern Baja California on Wednesday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Octave weakened far to the southwest of Baja California.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Octave was located at latitude 15.2°N and longitude 118.0.°W which put the center about 750 miles (1205 km) southwest of the southern tip of Baja California.  Octave was moving toward the east at 7 m.p.h. (11 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 1000 mb.