Tag Archives: Haiti

Very Dangerous Hurricane Irma Reaches Cat. 5

Very dangerous Hurricane Irma reached category 5 on the Saffir-Simpson Scale on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Irma was located at latitude 12.3°N and longitude 39.1°W which put it about 225 miles (365 km) east of Antigua.  Irma was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 180 m.p.h. (285 km/h) and there were wind gusts to 210 m.p.h. (340 km/h).  The minimum surface pressure was 931 mb.

Hurricane Warnings are in effect for Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, Sint Maarten, St. Martin, St. Barthelemy, the British Virgin Islands, the U.S. Virgin Islands, Puerto Rico, Vieques and Culebra.  Tropical Storm Warnings are in effect for Guadeloupe and Dominica.  Hurricane Watches are in effect for Guadeloupe, the southeastern Bahamas including the Acklins, Crooked Islands, Long Cay, the Inaguas, Mayaguana, and the Ragged Islands.  A Hurricane Watch is also in effect for the portion of the the coast from Cabo Engano, Dominican Republic to Le Mole St. Nicholas, Haiti.  Tropical Storm Watches are in effect for the portion of the coast from Le Mole St. Nicholas to Port Au Prince, Haiti and from Cabo Engano to Isla Saona, Dominican Republic.

Hurricane Irma intensified rapidly after the completion of the most recent eyewall replacement cycle.  The structure evolved in a large classic Cape Verde hurricane.  The is a large circular eye at the center of circulation.  A ring of very strong thunderstorms surrounds the eye and the strongest winds are occurring in that ring.  Bands of showers and thunderstorms are revolving around the core of Hurricane Irma.  Winds to hurricane force extend out about 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extend out about 160 miles (260 km) from the center.

The Hurricane Intensity Index (HII) for Irma is 44.1.  The Hurricane Size Index (HSI) is 19.8 and the Hurricane Wind Intensity Size Index (HWISI) is 63.9.  Hurricane Irma is as strong as Hurricane Rita was in 2005, but Irma is just slightly smaller than Rita was.  Hurricane Irma is capable of causing widespread catastrophic damage.

Hurricane Irma is moving through an environment that is very favorable for hurricanes.  Irma is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Hurricane Irma will likely remain very strong as long as it stays over water.  Additional eyewall replacement cycles could occur and they would result in fluctuations in the intensity of Hurricane Irma.

Hurricane Irma is being steered to the west by a very strong subtropical high over the Atlantic Ocean.  Irma is expected to turn a little more toward the west-northwest as it moves closer to the western end of the high.  On its anticipated track Hurricane Irma will move across the northern Leeward Islands during the next 24 hours.  It will be near Puerto Rico on Wednesday and near the Dominican Republic on Thursday.

Hurricane Irma is an very dangerous hurricane.  It is capable of producing widespread catastrophic damage.  Hurricane Irma will also drop extremely heavy rain and flooding is very possible.

Hurricane Irma Strengthens to Cat. 4, Watch in effect for Puerto Rico

Hurricane Irma strengthened to Category 4 on the Saffir-Simpson Scale on Monday and a Hurricane Watch was issued for Puerto Rico and the U.S. Virgin Islands.  At 5:00 p.m. EDT on Monday the center of Hurricane Irma was located at latitude 16.7°N and longitude 54.4°W which put it about 490 miles (790 km) east of the Leeward Islands.  Irma was moving toward the west at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 944 mb.

Hurricane Warnings are in effect for Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, St. Maarten, St. Martin, and St. Barthelemy.  Hurricane Watches are in effect for Guadeloupe, the British Virgin Islands, the U.S. Virgin Islands, Puerto Rico, Vieques and Culebra.  A Tropical Storm Warning is in effect for Guadeloupe.  A Tropical Storm Watch is in effect for Dominica.

The circulation of Hurricane Irma has been going through a series of eyewall replacement cycles.  A plane flying through Irma reported concentric eyewalls earlier today.  The two eyewalls appear to have merged.  A small circular eye is at the center of circulation.  A ring of strong thunderstorms surrounds the eye and the strongest winds are occurring in that ring of storms.  Additional bands of showers and thunderstorms are revolving around the core of Hurricane Irma.  Storms around the center are generating strong upper level divergence which is pumping away mass in all directions from the hurricane.

Hurricane Irma has been increasing in size.  Winds to hurricane force extend out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extend out about 140 miles (225 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Irma is 25.1.  The Hurricane Size Index (HSI) is 13.6.  The Hurricane Wind Intensity Size index (HWISI) is 38.7.

Hurricane Irma will move through an environment very favorable for tropical cyclones.  Irma will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Hurricane Irma could strengthen further and it has a chance to reach Category 5 on the Saffir-Simpson Scale.  Hurricane Irma is likely to go through additional eyewall replacement cycles, which will cause fluctuations in its intensity, but Irma should remain a strong hurricane as it nears the northern Leeward Islands.

The subtropical high pressure system over the Atlantic Ocean has been steering Hurricane Irma toward the west and that general motion is expected to continue for another 12 to 24 hours.  After that time Irma is expected to turn more toward the west-northwest.  On its anticipated track Hurricane Irma will approach the northern Leeward Islands late on Tuesday.  Hurricane Irma could approach Puerto Rico on Wednesday.

Hurricane Matthew Crosses Southwest Haiti, Watches Issued for Florida

Hurricane Matthew crossed the western end of the Tiburon Peninsula of Haiti on Tuesday morning.  The eye emerged intact over the Golfe de la Gonave and the center of Hurricane Matthew is about half way between Haiti and the eastern end of Cuba.  At 2:00 pm. EDT on Tuesday the center of Hurricane Matthew was located at latitude 19.4°N and longitude 74.3°W which put it about 65 miles (105 km) east-southeast of Guantanamo, Cuba.  Matthew was moving toward the north at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 949 mb.

A Hurricane Watch has been issued for the portion of the coast of Florida from Deerfield Beach to the Volusia/Brevard County line.  A Tropical Storm Watch has been issued from Seven Mile Bridge in the Florida Keys to Deerfield Beach.  Hurricane Warnings are in effect for Haiti and the Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma and Las Tunas.  Hurricane Warnings are also in effect for the Southeastern Bahamas including the Inaguas, Mayaguana, Acklins, Crooked Island, Long Cay, Ragged Island, and for the Central Bahamas including Long Island, Exuma, Rum Cay, San Salvador and Cat Island.  A Hurricane Warning is in effect for the northwestern Bahamas including the Abacos, Andros Island, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.  A Hurricane Watch has been issued for the Cuban province of Camaguey.  A Tropical Storm Warning is in effect for the Turks and Caicos and the south coast of the Dominican Republic from Barahona to Haiti.  Tropical Storm Watches have been issued for the northern coast of the Dominican Republic from Puerto la Plata to Haiti.

Even after passing over the mountains of the Massif de la Hotte on the southwestern peninsula of Haiti, the structure of Hurricane Matthew remained well organized.  Matthew has a circular eye with a diameter of 24 miles (39 km).  The eye is surrounded by a ring of strong thunderstorms.  The wind field around Hurricane Matthew actually expanded after it crossed southwestern Haiti.  Winds to hurricane force extend out about 60 miles (95 km) from the center of circulation.  Thunderstorms around the eye are generating upper level divergence which is pumping out mass in all directions.  Additional rainbands are rotating around the core of Matthew.

Hurricane Matthew is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is 30°C.  The winds in the upper levels are weak and the is little vertical wind shear.  Hurricane Matthew could weaken slightly when the center passes over eastern Cuba, but it will likely restrengthen when it moves over the very warm water around the Bahamas.  Matthew is likely to remain a Category 4 hurricane on the Saffir-Simpson Scale. and it could become a Category 5 hurricane while it is moving over the Bahamas.  Hurricane Joaquin almost reached Category 5 while it was near the Bahamas in early October last year.

Matthew is moving around the western end of subtropical high pressure system, which is steering the hurricane toward the north.  That general motion is expected to continue for another 12 hours or so.  The high is expected to strengthen and extend west on Wednesday.  When that happens, Hurricane Matthew will be steered more toward the northwest.  On its anticipated track Hurricane Matthew will move across the eastern end of Cuba later on Tuesday and across the Bahamas on Wednesday.  Hurricane Matthew could be very near the east coast of Florida on Thursday.  Matthew could come very close to the coast of South Carolina on Friday and it could be near the coast of North Carolina on Saturday morning.  It is still not clear if the eye of Hurricane Matthew will reach landfall in any of those places.

The Hurricane Intensity Index (HII) for Matthew is 29.8.  The Hurricane Size Index (HSI) is 19.5 and the Hurricane Wind Intensity Size Index (HWISI) is 49.3.  Those indices mean that Hurricane Matthew is capable of causing regional significant wind damage.  Matthew will also generate a significant storm surge over eastern Cuba and the Bahamas.  Water level rises will occur along the southeast coast of the U.S. where easterly winds push the water toward the shore.  Hurricane Matthew is stronger, but a little smaller than Hurricane Jeanne was in 2004, when Jeanne made landfall on the coast of Florida.

Hurricane Matthew Moves Toward Haiti, Threat to U.S. Increases

Hurricane Matthew moved toward Haiti on Monday and the threat to the U.S. increased.  At 5:00 pm. EDT on Monday the center of Hurricane Matthew was located at latitude 16.3°N and longitude 74.7°W which put it about 140 miles (220 km) south of Tiburon, Haiti.  Matthew was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 940 mb.

Hurricane Warnings are in effect for Haiti and the Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma and Las Tunas.  Hurricane Warnings are also in effect for the Southeastern Bahamas including the Inaguas, Mayaguana, Acklins, Crooked Island, Long Cay, Ragged Island, and for the Central Bahamas including Long Island, Exuma, Rum Cay, San Salvador and Cat Island.  Hurricane Watches have been issued for the Cuban province of Camaguey and the northwestern Bahamas including the Abacos, Andros Island, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence, and for the Turks and Caicos.  A Tropical Storm Warning is in effect for Jamaica and the south coast of the Dominican Republic from Barahona to Haiti.  Tropical Storm Watches have been issued for the northern coast of the Dominican Republic from Puerto la Plata to Haiti.

The structure of Hurricane Matthew is well organized.  It has a circular eye with a diameter of 18 miles (29 km).  The eye is surrounded by a ring of strong thunderstorms.  Winds to hurricane force extend out about 40 miles (65 km) from the center of circulation.  Thunderstorms around the eye are generating upper level divergence which is pumping out mass in all directions.  Additional rainbands are rotating around the core of Matthew.

The Hurricane Intensity Index (HII) for Matthew is 28.2.  The Hurricane Size Index (HSI) is 15.1 and the Hurricane Wind Intensity Size Index (HWISI) is 43,3.  These indices suggest that Hurricane Matthew is capable of causing regional significant wind damage to Haiti.  Hurricane Matthew is very similar in size and intensity to what Hurricane Dennis was when Dennis hit northwest Florida in 2005.  Hurricane Matthew is stronger and a little bigger than Hurricane Sandy was when Sandy was over the northwestern Caribbean Sea in 2012.

Hurricane Matthew is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is not much vertical wind shear.  Matthew is likely to maintain its intensity as it moves toward Haiti.  If a rainband wraps around the eye, then an eyewall replacement cycle could cause temporary fluctuations in intensity.  The future path of Matthew could have a big impact on the intensity of the hurricane.  If the center of Matthew moves over southwestern Haiti, then the Massif de la Hotte could seriously disrupt the lower levels of the circulation.  Mountains in Massif de la Hotte extend up to 7700 feet (2347 meters).  On the other hand, if the eye and eyewall move just west of Haiti, then the inner core is likely to remain intact.  The water around the Bahamas is very warm and if the core of Hurricane Matthew is reasonably intact when it gets there, Matthew will likely regain its intensity.

Hurricane Matthew is moving around the southwestern end of a subtropical high pressure system, which has allowed the hurricane to move just east of due north.  That general motion is expected to continue for another day or so.  In about 24 hours the subtropical high is expected to strengthen and extend westward.  If the high does strengthen, it will force Hurricane Matthew to move more toward the northwest.  Guidance from numerical models has supported this scenario today.  The northwest motion could take Hurricane Matthew over the Central and Northwestern Bahamas during the middle of the week.  A northwesterly track could bring Hurricane Matthew close to Florida on Thursday and near the Mid-Atlantic Coast on Friday.  Based on guidance from the forecast models, the threat to the U.S. increased significantly on Monday.

Hurricane Matthew has the potential to cause regional significant wind damage to Haiti.  Even if the center moves west of Haiti, Matthew will produce very heavy rain and the potential for devastating flash floods and mudslides exists.  There will also be significant storm surges along the coasts of Haiti, the Dominican Republic and eastern Cuba.

Hurricane Matthew Moving Slowly North Toward the Greater Antilles

Powerful Hurricane Matthew was moving slowly north over the Northwestern Caribbean Sea on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Hurricane Matthew was located at latitude 14.7°N and longitude 75.0°W which put it about 255 miles south-southeast of Kingston, Jamaica.  Matthew was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 943 mb.

Hurricane Warnings are in effect for Haiti, Jamaica, the Cuban provinces of Guantanamo, Santiago de Cuba, Holguin, Granma and Las Tunas.  Hurricane Warnings are also in effect for the Southeastern Bahamas including the Inaguas, Mayaguana, Acklins, Crooked Island, Long Cay and Ragged Island.  A Hurricane Watch has been issued for the Cuban province of Camaguey, the Central Bahamas and the Turks and Caicos.  A Tropical Storm Warning is in effect for the south coast of the Dominican Republic from Barahona to the border with Haiti.  A Tropical Storm Watch has been issued for the north coast of the Dominican Republic from Puerto la Plata to the border with Haiti.

Matthew is a very well organized symmetrical hurricane.  There is a circular eye with a diameter of about 14 miles (22 km).  The eye is surrounded by a ring of strong thunderstorms.  Numerous bands of thunderstorms are rotating around the core of the circulation.  The thunderstorms are generating well developed upper level divergence which is pumping out mass.

The Hurricane Intensity Index (HII) is 29.9.  The Hurricane Size index (HSI) is 10.4 and the Hurricane Wind Intensity Size Index (HWISI) is 40.3.  The indices indicate that Hurricane Matthew is as strong as Hurricane Dennis was in 2005, but Matthew is a little smaller than Dennis was.

Hurricane Matthew will be moving through a very favorable environment.  Matthew will be moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  There could be some fluctuations in intensity, especially if eyewall replacement cycles occur.  Matthew is likely to remain a powerful hurricane.

Hurricane Matthew has reached the western end of a subtropical high pressure system.  Matthew is likely to continue to move north around the western end of the subtropical high.  On its anticipated track Hurricane Matthew could be near Jamaica and western Haiti on Monday night.  Matthew could reach eastern Cuba on Tuesday and it could be over the Bahamas on Wednesday.

Hurricane Matthew is capable of causing region significant wind damage.  It will bring locally heavy rain to parts of Haiti, Jamaica and Cuba.  Matthew will also create dangerous storm surges along the coast.

Powerful Hurricane Matthew Turns Northwest

After completing a tight slow cyclonic loop near the northern coast of Colombia, Hurricane Matthew started moving toward the northwest on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Hurricane Matthew was located at latitude 13.8°N and longitude 73.6°W which put it about 360 miles (580 km) southeast of Kingston, Jamaica.  Matthew was moving toward the north-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 940 mb.

A Hurricane Warning has been issued for Jamaica.  A Hurricane Warning is in effect for the coast of Haiti from the southern border with the Dominican Republic to Le Mole St. Nicholas.  A Hurricane Watch is in effect from Le Mole St. Nicholas to the northern border with the Dominican Republic.  A Hurricane Watch is also in effect for Cuba from Camaguey province to Guantanamo province.

Matthew is a compact hurricane.  It has a circular eye with a diameter of less than 10 miles (16 km).  The eye is surrounded by a tight ring of strong thunderstorms and the strongest winds are occurring in that ring.  Additional rainbands are rotating around the core of the circulation.  Thunderstorms in the core are generating upper level divergence which is pumping out mass to the east of Hurricane Matthew.

The Hurricane Intensity Index (HII) is 31.6.  The Hurricane Size Index (HSI) is 10.3 and the Hurricane Wind Intensity Size index (HWISI) is 41.9.  The indices indicate that Hurricane Matthew is as intense and a little smaller than Hurricane Dennis was when Dennis was over the northwestern Caribbean Sea in 2005.

Hurricane Matthew will continue to move through a favorable environment on Sunday.  It will move over water where the Sea Surface Temperature is near 30°.  An upper level trough west of Matthew will generate southwesterly winds which will blow near the northwestern part of the hurricane.  Although there will be some vertical wind shear, it may not have a significant impact on Hurricane Matthew.  If one of the rainbands wraps around the existing eye, then an eyewall replacement cycle could cause a temporary weakening of Hurricane Matthew.

Hurricane Matthew is moving around the western end of a subtropical high pressure system.  The combination of the subtropical high and the upper level trough to the west of Matthew should steer the hurricane toward the north-northwest on Sunday.  On its anticipate track Hurricane Matthew could reach Jamaica and southern Haiti on Monday afternoon.  Matthew could reach eastern Cuba on Monday night and it could be over the southeastern Bahamas on Tuesday.

Hurricane Matthew is a dangerous hurricane.  The indices suggest that it is capable of causing significant regional wind damage.  It could also bring flooding rains to parts of Haiti.  Hurricane Matthew could also produce dangerous storm surges on the south coasts of Haiti, Jamaica and Cuba.

Hurricane Matthew Becomes the First Category 5 Atlantic Hurricane Since 2007

Hurricane Matthew continued its rapid intensification on Friday night and it became the first Atlantic hurricane to reach Category 5 on the Saffir-Simpson Scale since Hurricane Felix did so in 2007.  At 11:00 p.m. EDT on Friday the center of Hurricane Matthew was located at latitude 13.3°N and longitude 72.3°W which put it about 440 miles (710 km) southeast of Kingston, Jamaica.  Matthew was moving toward the west at 7 m.p.h. (11 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 941 mb.

The Hurricane Intensity Index (HII) for Matthew was 35.0.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 48.7.  These indices indicate that Hurricane Matthew is not as intense and slightly smaller than Hurricane Wilma was, when Wilma was a Category 5 hurricane over the northwestern Caribbean Sea in 2005.

A Hurricane Watch is in effect for Jamaica.  A Tropical Storm Watch is in effect for the portion of the coast from the Haiti/Dominican Republic border to Port-Au-Prince, Haiti.  A Tropical Storm Warning is in effect for the portion of the coast from the Colombia/Venezuela border to Riohacha, Colombia.

Hurricane Matthew remains in a very favorable environment of minimal vertical wind shear and warm Sea Surface Temperatures.  The intensity may fluctuate as a result of eyewall replacement cycles.

A strong subtropical high is steering Hurricane Matthew toward the west.  Matthew is slowing as it approaches the western end of the subtropical high.  It will turn toward the north when it reaches the western end of that high pressure system.  However, the location, time and sharpness of the turn to the north are still uncertain.  That uncertainty means that the longer term track of Hurricane Matthew is also uncertain.  We should get more clarity about the future direction of Hurricane Matthew during the next several days.

Matthew Rapidly Intensifies Into Category 4 Hurricane

Hurricane Matthew intensified very rapidly into a Category 4 hurricane on the Saffir-Simpson Scale as it moved across the southern Caribbean Sea on Friday.  At 5:00 p.m. EDT on Friday the center of Hurricane Matthew was located at latitude 13.5°N and longitude 71.6°W which put it about 75 miles (120 km) north of Punta Gallinas, Colombia.  Matthew was moving toward the west-southwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h). and there were wind gusts t0 165 m.p.h. (265 km/h).  The minimum surface pressure was 949 mb.

The Hurricane Size Index (HII) was 28.3.  The Hurricane Intensity Index (HII) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 41.5.  The indices mean that Hurricane Matthew is very similar in size and intensity to what Hurricane Ike was when Ike was northeast of the Leeward Islands in 2008.  The indices also mean that Hurricane Matthew is capable of producing regional significant wind damage.

Hurricane Matthew is very well organized and it efficiently extracted energy from the warm water of the Caribbean Sea to intensify rapidly on Friday.  It has a circular eye with a diameter of about 15 miles (24 km).  The eye is surrounded by a ring of very tall thunderstorms.  The thunderstorms are pumping out large quantities of mass which allowed the surface pressure to decrease by 44 mb during the past 24 hours.  There additional bands of thunderstorms, mainly in the eastern half of the circulation.

Hurricane Matthew will remain in a very favorable environment while it is over the Caribbean Sea.  It could intensify further.  When hurricanes become as strong as Matthew strong, they sometimes undergo eyewall replacement cycles.  During an eyewall replacement cycle, a hurricane first weakens and then strengthens again when the innermost eyewall dissipates.  If eyewall replacement cycles occur in Hurricane Matthew, then the intensity will fluctuate.

A strong subtropical high pressure system north of Matthew is steering the hurricane toward the west-southwest.  That general motion is expected to continue for another 24 hours.  When Matthew reaches the western end of the subtropical high, it will start to move toward the north.  Guidance from numerical models is still divergent about the details of the turn toward the north.  If the turn is sharper, it could mean that Hurricane Matthew moves toward Haiti.  If the turn is more gradual, it could mean that Matthew heads for Jamaica and eastern Cuba.  The uncertainty is the reason why watches have been posted for both Jamaica and Haiti.

Matthew is a very powerful hurricane.  It is capable of causing regional significant wind damage.  In addition Matthew will produce very heavy rain and the potential for dangerous flash flooding.  There is also the possibility of a significant storm surge along the coast.

Matthew Becomes a Hurricane Over the Eastern Caribbean Sea

Tropical Storm Matthew strengthened into a hurricane on Thursday as it moved over the eastern Caribbean Sea.  At 8:00 p.m. EDT on Thursday the center of Hurricane Matthew was located at latitude 14.2°N and longitude 68.1°W which put it about 150 miles (240 km) north-northeast of Curacao.  Matthew was moving toward the west at 15 m.p.h. (24 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 987 mb.

Tropical Storm Watches are in effect for Curacao, Bonaire and Aruba.  The government of Columbia has also issued a Tropical Storm Watch for the portion of the coast from the Columbia/Venezuela border to Riohacha.

The structure of Hurricane Matthew became much better organized on Thursday.  A primary rainband wrapped around the center of circulation.  An eye appears to be forming.  A ring of strong thunderstorms surrounds the eye on all sides except to the south.  Additional bands of thunderstorms developed in the northern and eastern parts of the circulation.  The storms near the eye generated upper level divergence which pumped out mass to the north and east of Hurricane Matthew.  The upper level divergence pumped out enough mass to allow the minimum pressure to decrease by 17 mb during the past 24 hours.

Hurricane Matthew will be moving into an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the western Caribbean Sea and an upper level ridge just east of Matthew are producing southwesterly winds which are blowing across the top of the hurricane.  The vertical wind shear made Hurricane Matthew’s structure asymmetrical earlier today, but the shear has been less in recent hours.  The effect of the wind shear will be to slow the rate of intensification, but it will not prevent intensification.  Hurricane Matthew will pass just north of the cost of South America and drier air could also slow the rate of intensification.

A strong subtropical high pressure system to the north of Matthew is steering the hurricane toward the west and that general motion is expected to continue for about another 48 hours.  When Hurricane Matthew reaches the western end of the ridge, it will turn toward the north.  Guidance from the numerical models continues to be quite divergent about when, where and how sharp the turn will be.  If Hurricane Matthew turns sooner and sharper, it could move over Haiti early next week.  On the other hand, if Matthew turns later and more gradually, it could affect Jamaica and eastern Cuba.  It is too early to know which scenario will eventually occur.

Hurricane Matthew could become a major hurricane over the Caribbean Sea and interests in the Greater Antilles should monitor its progress.

Tropical Depression 12 Forms and Warnings Issued for the Bahamas

A small center of circulation developed within a larger disturbance near the Bahamas and the National Hurricane Center classified it as Tropical Depression 12 (TD12).  At 10:00 p.m. EDT on Sunday the center of Tropical Depression 12 was located at latitude 23.0°N and longitude 73.0°W which put it about 115 miles (185 km) southeast of San Salvador in the Bahamas and about 30 miles (50 km) north of Mayaguana.  TD12 was moving toward the northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1010 mb.

Tropical Storm Warnings have been issued for the Central and Northwestern Bahamas and for the Acklins, Samana Cays, Crooked Island and Long Cay in the Southeastern Bahamas.

Tropical Depression 12 formed when a tropical wave interacted an upper level low.  Tropical cyclones that develop in that manner tend to be poorly organized in their early stages.  Most of the stronger thunderstorms are located east and south of the center of circulation.  The surface center is located on the western edge of the convection.

Although Tropical Depression 12 is over water where the Sea Surface Temperature is near 28°C, the upper level environment is marginal for intensification.  An upper level low near southwest of the depression is generating southerly upper level winds over the western part of TD12.  A small upper level high is over the eastern part of TD12.  The upper level high is generating some divergence to the east of the depression.  Some further intensification is possible and the depression could become Tropical Storm Kate on Monday.

Tropical Depression 12 could bring rain and squally weather to parts of the Bahamas.  It is near some of the same places that were hit by Hurricane Joaquin last month and it could hinder recovery efforts.