Tag Archives: Bahamas

Strong Upper Level Winds Shear Top Off Tropical Storm Franklin

Strong upper level winds sheared the top off of Tropical Storm Franklin on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Franklin was located at latitude 21.8°N and longitude 67.8°W which put it about 215 miles (340 km) east-northeast of Grand Turk Island. Franklin was moving toward the east-southeast at 5 m.p.h. (8 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 1003 mb.

An upper level trough northeast of the Bahamas produced strong west-northwesterly winds that blew the top off of Tropical Storm Franklin on Friday morning. The strong upper level winds sheared off the tops of thunderstorms near the center of Franklin’s circulation and in the western side of the tropical storm. Bands near the center of Tropical Storm Franklin and in the western half of the circulation consisted primarily of showers and lower clouds. The remaining thunderstorms were occurring in bands in the southeastern part of Franklin’s circulation

The strong vertical wind shear also affected the distribution of winds in Tropical Storm Franklin. Winds to tropical storm force extended out 115 miles (185 km) in the eastern side of Franklin’s circulation. Winds to tropical storm force only extended out 35 miles (55 km) in the western half of the circulation.

Tropical Storm Franklin will move through an environment only marginally favorable for intensification during the next 24 hours. Franklin will move over water where the Sea Surface Temperatures are near 30°C. However, the upper level trough northeast of the Bahamas will continue to produce west-northwesterly winds that will blow toward the top of Franklin’s circulation. Those winds will continue to cause strong vertical wind shear. The wind shear will inhibit intensification and the shear could be strong enough to cause Tropical Storm Franklin to weaken during the next 24 hours.

The upper level trough east of Florida will steer Tropical Storm Franklin toward the east during the rest of Friday. The upper level trough could turn Franklin toward the north on Saturday. On its anticipated track, Tropical Storm Franklin will move farther away from the Turks and Caicos. Franklin is forecast to remain well to the north of Puerto Rico.

Tropical Storm Fred Passes South of Puerto Rico

Tropical Storm Fred was passing south of Puerto Rico on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Fred was located at latitude 17.6°N and longitude 66.8°W which put it about 45 miles (75 km) south-southwest of Ponce, Puerto Rico. Fred was moving toward the west at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1009 mb.

Tropical Storm Warnings were in effect for Puerto Rico including Culebra and Vieques and the U.S. Virgin Islands. A Tropical Storm Warning was also in effect for the portion of the coast from Punta Palenque to Cabo Frances Viejo, Dominican Republic. A Tropical Storm Watch was in effect for the portion of the coast from Cabo Frances Viejo to the northern border with Haiti. A Tropical Storm Watch was in effect for the portion of the coast from Gonaives, Haiti to the northern border with the Dominican Republic. Tropical Storm Watches were also in effect for the Southeastern Bahamas and the Turks and Caicos.

A reconnaissance plane was able to identify a low level center of circulation in a low pressure system previously designated at Potential Tropical Cyclone Six on Tuesday evening and the National Hurricane Center upgraded the system to Tropical Storm Fred. The circulation around Tropical Storm Fred was still organizing. The low level center was about 45 miles (75 km) to the north of the center of circulation in the middle levels. The circulation in the middle levels was moving closer to the low level center. The strongest thunderstorms were occurring on the southern side of the low level center and near the center in the middle levels. Winds to tropical storm force extended out 45 miles (75 km) from the center in the northeastern quadrant of Fred. Winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Fred will move through an environment favorable for intensification during the next 12 hours. Fred will move over water where the Sea Surface Temperatures are near 28°C. It will be under a small upper level ridge. The upper level winds in the ridge are weak and there will be little vertical wind shear. Tropical Storm Fred is likely to strengthen during the next 12 hours. The center of Fred will be near the eastern part of the Dominican Republic in about 12 hours. Tropical Storm Fred is likely to weaken on Wednesday while the center is near Hispaniola.

Tropical Storm Fred will move of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Fred toward the west-northwest during the next several days. On its anticipated track Tropical Storm Fred will approach the eastern Dominican Republic in 12 hours. Fred could be over the northern coast of Hispaniola on Wednesday night. Bands in the northern side of Tropical Storm Fred will produce gusty winds and locally heavy rain over Puerto Rico on Tuesday night. Fred could drop heavy rain on parts of the Dominican Republic and Haiti on Wednesday. Heavy rain could cause flash floods in some locations.

Tropical Storm Eta Strengthens, Hurricane Watch for Florida

Tropical Storm Eta strengthened a little more Saturday evening and A Hurricane Watch was issued for parts of South Florida and the Florida Keys. At 10:00 p.m. EST on Saturday the center of Tropical Storm Eta was located at latitude 20.7°N and longitude 79.9°W which put it about 140 miles (220 km) west-southwest of Camaguey, Cuba. Eta was moving toward the northeast at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 991 mb.

A Hurricane Watch was in effect for the portion of the coast from Deerfield Beach to Bonita Beach, Florida and for the Florida Keys from Ocean Reef to the Dry Tortugas. A Tropical Storm Warning was in effect for the portion of the coast from the Brevard/Volusia County Line to Englewood, Florida. A Tropical Storm Warning was in effect for the Florida Keys from Ocean Reef to the Dry Tortugas. Tropical Storm Warnings were in effect for the Cayman Islands and the Cuban provinces of Camaguey, Ciego de Avila, Sancti Spiritus, Villa Clara, Cienfuegos and Matanzas. A Tropical Storm Warning was in effect for the Northwestern Bahamas including the Abacos, Andros Island, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence. A Tropical Storm Watch was in effect for the portion of the coast from Englewood to Anna Maria Island, Florida. A Tropical Storm Watch was in effect for Lake Okeechobee. A Tropical Storm Watch was in effect for the Cuban provinces of La Habana, Artemisa y Mayabeque, Pinar del Rio and the Isle of Youth.

The circulation around Tropical Storm Eta continued to strengthen on Saturday evening. There were occasional infrared satellite images that suggested a small eye could be forming at the center of Eta. There was a ring of strong thunderstorms around the center and the strongest winds were occurring in that ring of storms. Storms near the core of Eta generated upper level divergence which pumped mass away to the northeast of the tropical storm. The strongest rainbands were in the northern and eastern parts of the circulation around Tropical Storm Eta. Bands south and west of the center consisted primarily of showers and lower clouds. The strongest winds were blowing in the northern half of Eta. Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation.

Tropical Storm Eta will move through an environment favorable for intensification during the few hours. Eta will move over water where the Sea Surface Temperature is near 29°C. An upper level trough over the Gulf of Mexico will produce southwesterly winds which will blow toward the top of Tropical Storm Eta. Those winds will cause moderate vertical wind shear. The shear will inhibit intensification, but it may not be strong enough to prevent Eta from getting stronger. Tropical Storm Eta is likely to weaken when it crosses Cuba on Saturday night. The Sea Surface Temperature of the water north of Cuba is near 29°C. So, Eta is likely to strengthen after it crosses Cuba. Eta could strengthen to a hurricane when it approaches the Florida Keys.

The upper level trough will make a transition to a cutoff low over the southeastern Gulf of Mexico which will be the primary feature steering Eta. Counterclockwise rotation around the cutoff low will pull Eta toward the northeast on Saturday night . On its anticipated track Eta could move across Cuba west of Camaguey on Saturday night. Tropical Storm Eta will drop heavy rain when it moves across Cuba and flash floods could occur. The upper low will steer Eta toward the northwest on Sunday. Eta will approach the Florida Keys on Sunday night. It could be a hurricane at that time. Eta will bring gusty winds and locally heavy rain to the Florida Keys and South Florida. A high pressure system over the Atlantic Ocean will interact with the circulation around the northern side of Eta to produce strong easterly winds which will blow toward the coast of Southeast Florida. Those winds will push water toward the coast and the water level could rise up to six feet (2 meters). The strong winds could also cause widespread power outages in South Florida.

Eta Strengthens Back to Tropical Storm, Warnings Issued for Florida

Former Tropical Depression Eta strengthened back to a tropical storm on Saturday morning and Tropical Storm Warnings for parts of South Florida and the Florida Keys. At 1:00 p.m. EST on Saturday the center of Tropical Storm Eta was located at latitude 20.0°N and longitude 80.1°W which put it about 50 miles (80 km) north of Grand Cayman Island. Eta was moving toward the northeast at 17 m.p.h. (28 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 995 mb.

A Tropical Storm Warning was issued for the portion of the coast from Golden Beack to Chokoloskee, Florida. A Tropical Storm Warning was issued for the Florida Keys from Ocean Reef to the Dry Tortugas. Tropical Storm Warnings were in effect for the Cayman Islands and the Cuban provinces of Camaguey, Ciego de Avila, Sancti Spiritus, Villa Clara, Cienfuegos and Matanzas. A Tropical Storm Warning was in effect for the Northwestern Bahamas including the Abacos, Andros Island, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence. Tropical Storm Watches were issued for the portion of the coast from Chokoloskee to Englewood, Florida and from JGolden Beach to the Brevard/Volusia County Line. A Tropical Storm Watch was in effect for Lake Okeechobee. A Tropical Storm Watch was in effect for the Cuban provinces of La Habana, Artemisa y Mayabeque, Pinar del Rio and the Isle of Youth.

Observations from a U.S. Air Force Reserve Hurricane Hunter plane and from Grand Cayman Island indicated that the center of former Tropical Depression Eta reformed in a cluster of thunderstorms near Grand Cayman. The reconnaissance plane was still sampling the circulation around Tropical Storm Eta but the available date suggested that it was much better organized. The inner end of a rainband was wrapping around the eastern and northern part of the center of circulation. Other bands of showers and thunderstorms were revolving around the core of Eta. Storms near the core were generating upper level divergence which was pumping mass away to the northeast of the tropical storm. The removal of mass was allowing the surface pressure to decrease and Tropical Storm Eta was intensifying more quickly. Winds to tropical storm force extended out 60 miles (95 km) from the center of Eta.

Tropical Storm Eta will move through an environment favorable for intensification during the next 12 to 18 hours. Eta will move over water where the Sea Surface Temperature is near 29°C. It will initially be under an upper level ridge where the winds are weaker. There will be less vertical wind shear under the ridge. Eta could intensify rapidly during the next 12 hours and it could strengthen to a hurricane. Eta is likely to weaken when it crosses Cuba on Saturday night . The Sea Surface Temperature of the water north of Cuba is near 29°C. So, Eta is likely to strengthen after it crosses Cuba. Eta could strengthen to a hurricane when it approaches South Florida. An upper level low over the western Gulf of Mexico will produce southwesterly winds which will blow toward the top of Eta on Sunday. Those winds will cause more vertical wind shear, which could limit further intensification of Eta. The wind shear caused by the upper low could eventually cause Eta to develop a structure more like a subtropical cyclone.

An upper low over the western Gulf of Mexico will be the primary feature steering Eta. Counterclockwise rotation around the cutoff low will pull Eta more toward the northeast on Saturday. On its anticipated track Eta could move across Cuba on Saturday night and it could drop heavy rain when it does so. The upper low will steer Eta toward the northwest on Sunday. Eta will approach South Florida and the Florida Keys on Sunday night. It could be a hurricane at that time. Eta will bring gusty winds and locally heavy rain to the Florida Keys and South Florida. A high pressure system over the Atlantic Ocean will interact with the circulation around the northern side of Eta to produce strong easterly winds which will blow toward the coast of Southeast Florida. Those winds will push water toward the coast and the water level could rise up to six feet (2 meters).

Tropical Depression Eta Prompts Watches for South Florida, Keys and Northwest Bahamas

Expected intensification of Tropical Depression Eta prompted the issuance of Tropical Storm Watches for parts of South Florida, the Florida Keys and the Northwestern Bahamas. At 10:00 p.m. EST on Friday the center of Tropical Depression Eta was located at latitude 18.0°N and longitude 85.2°W which put it about 275 miles (445 km) west-southwest of Gran Cayman Island. Eta was moving toward the northeast at 12 m.p.h. (19 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 1002 mb.

Tropical Storm Warnings were in effect for the Cayman Islands and the Cuban provinces of Camaguey, Ciego de Avila, Sancti Spiritus, Villa Clara, Cienfuegos and Matanzas. A Tropical Storm Watch was issued for the coast of South Florida from Jupiter Inlet to Bonita Beach. It included Lake Okeechobee. A Tropical Storm Watch was issued for the Florida Keys from Ocean Reef to the Dry Tortugas. A Tropical Storm Watch was in effect for the Cuban provinces of La Habana, Artemisa y Mayabeque, Pinar del Rio and the Isle of Youth. A Tropical Storm Watch was issued for the Northwestern Bahamas including the Abacos, Andros Island, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.

The structure of the circulation around Tropical Depression Eta exhibited a little more organization on satellite imagery on Friday evening. More thunderstorms developed near the center of Eta. There were also more thunderstorms in bands in the eastern half of the circulation. Bands in the western half of Eta contained more showers and lower clouds. Storms near the center of Eta generated upper level divergence which pumped mass away to the northeast of the depression. Removal of mass could allow the surface pressure to decrease on Saturday.

Tropical Depression Eta will move through an environment favorable for intensification on Saturday. Eta will move over water where the Sea Surface Temperature is near 29°C. It will initially be under an upper level ridge where the winds are weaker. There will be less vertical wind shear under the ridge and Eta is likely to strengthen back to a tropical storm on Saturday. A upper level low over the western Gulf of Mexico will produce southwesterly winds which will blow toward the top of Eta on Sunday. Those winds will cause more vertical wind shear, which could limit further intensification of Eta. Eta is also likely to weaken when it crosses Cuba on Sunday. The Sea Surface Temperature of the water north of Cuba is near 29°C. So, Eta is likely to strengthen after it crosses Cuba. Eta could strengthen to a hurricane when it approaches South Florida. The wind shear caused by the upper low could eventually cause Eta to develop a structure more like a subtropical cyclone.

The upper low over the western Gulf of Mexico will be the primary feature steering Eta. Counterclockwise rotation around the cutoff low will pull Eta more toward the northeast on Saturday. Eta could pass near the Cayman Islands on Saturday. Eta is likely to move across Cuba on Sunday morning and it could drop heavy rain when it does so. The upper low will steer Eta toward the northwest on Sunday. Eta will approach South Florida and the Florida Keys on Sunday night. It could bring gusty winds and locally heavy rain to the Keys and South Florida. A high pressure system over the Atlantic Ocean will interact with the circulation around the northern side of Eta to produce strong easterly winds which will blow toward the coast of Southeast Florida. Those winds will push water toward the coast and the water level will rise several feet.

Marco Strengthens to a Hurricane, Laura Drenches Hispaniola

Former Tropical Storm Marco strengthened into a hurricane on Sunday over the Gulf of Mexico while Tropical Storm Laura dropped drenching rain on Hispaniola.  At 2:00 p.m. EDT on Sunday the center of Hurricane Marco was located at latitude 25.3°N and longitude 87.4°W which put it about 280 miles (450 km) south-southeast of the Mouth of the Mississippi River.  Marco was moving toward the north-northwest at 14 m.p.h. (22 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 992 mb.

A Hurricane Warning was in effect for the portion of the coast from Morgan City, Louisiana to the Mouth of the Pearl River, Mississippi.  Hurricane Watches were in effect for the portion of the coast from Intracoastal City, Louisiana to Morgan City and for New Orleans, Lake Pontchartrain and Lake Maurepas.  A Tropical Storm Warning was in effect from the Mouth of the Pearl River to the Mississippi/Alabama border.  A Tropical Storm Watch was in effect for the portion of the coast from the Mississippi/Alabama border to the Alabama/Florida border.

Former Tropical Storm Marco strengthened into a hurricane on Sunday.  A small eye developed at the center of circulation.  A ring of thunderstorms surrounded eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Marco.  Storms near the core generated upper level divergence which pumped mass away to the northeast of the hurricane.

The circulation around Hurricane Marco was small.  Winds to hurricane force extended out 15 miles (25 km) from the center of circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center.

Hurricane Marco will move through an environment somewhat favorable for intensification during the next 18 hours.  Marco will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the northwestern Gulf of Mexico will produce southwesterly winds which will blow toward the top of Hurricane Marco.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent Marco from strengthening during the next 18 hours.

The upper level trough and a subtropical high pressure system over the Atlantic Ocean will steer Hurricane Marco toward the north-northwest during the next day or so.  On its anticipated track Hurricane Marco will approach southeast Louisiana on Monday.  Marco will bring gusty winds and drop locally heavy rain over southeastern Louisiana and southern Mississippi.

Elsewhere, Tropical Storm Laura dropped heavy rain on the Dominican Republic and Haiti.  There were reports of flash floods.  At 2:00 pm. EDT on Sunday the center of Tropical Storm Laura was located at latitude 19.4°N and longitude 74.3°W which put it about 80 miles (130 km) southeast of Guantanamo, Cuba.  Laura was moving toward the west-northwest at 21 m.p.h. (33 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 1004 mb.

Tropical Storm Warnings were in effect for the portion of the northern coast of the Dominican Republic from Samana to the border with Haiti and for the entire coast of Haiti.  Tropical Storm Warnings were in effect for the Turks and Caicos, the Acklins, Crooked Island, Long Cay, the Inaguas, and the Ragged Islands.  Tropical Storm Warnings were also in effect for the Cuban provinces of Las Tunas, Holguin, Guantanamo, Santiago de Cuba, Granma, Ciego de Avila, Sancti Spiritus, Villa Carla, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar del Rio and the Isle of Youth.  A Tropical Storm Watch was in effect for the Florida Keys to the Isle of Youth.  Tropical Storm Watches were also in effect for the Central Bahamas and Andros Island.

Tropical Storm Marco Strengthens, Hurricane Watch for New Orleans

Tropical Storm Marco strengthened on Saturday and a Hurricane Watch was issued for a portion of the central Gulf Coast.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Marco was located at latitude 21.9°N and longitude 68.1°W which put it about 50 miles (80 km) west of the western tip of Cuba.  Marco was moving toward the north-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 992 mb.

A Hurricane Watch was issued for the portion of the coast from Intracoastal City, Louisiana to the Mississippi/Alabama border including Lake Pontchartrain, Lake Maurepas and New Orleans.  A Tropical Storm Watch was in effect for the portion of the coast from the Mississippi/Alabama border to the Alabama/Florida border.  A Tropical Storm Warning was in effect for the Cuban province of Pinar del Rio.

Tropical Storm Marco exhibited much better organization on Saturday.  Weather radar on a reconnaissance plane and from Cuba as well as visible satellite images indicated that a small eye developed at the center of Marco.  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 core of Tropical Storm Marco.  Storms near the core were generating upper level divergence which was pumping away to the north of the tropical storm.  The circulation around Marco was small.  Winds to tropical storm force extended out 100 miles (160 km) to the east of the center of circulation.  Winds to tropical storm force only extended out 50 miles (80 km) on the western side of the tropical storm.

Tropical Storm Marco will move through an environment favorable for intensification during the nextt 24 hours.  Marco will move over water where the Sea Surface Temperature is near 30°C.  It will move east of an upper level trough over the Gulf of Mexico.  The trough will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear is not likely to be enough to prevent intensification.  Tropical Storm Marco is likely to intensify into a hurricane during the next 24 hours.  Since he circulation around Marco is small, the tropical storm could strengthen or weaken quickly if the environment changes.

The upper level trough and a subtropical high pressure system over the Atlantic Ocean will steer Tropical Storm Marco toward the north-northwest during the next 36 to 48 hours.  On its anticipated track Marco could approach southeastern Louisiana by Monday afternoon.  Marco could be a hurricane when it approaches the coast.

Elsewhere, Tropical Storm Laura dropped heavy rain over Puerto Rico and it prompted the issuance of a Tropical Storm Watch for the Florida Keys.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Laura was located at latitude 18.0°N and longitude 68.1°W which put it about 125 miles (200 km) east-southeast of Santo Domingo, Dominican Republic.  Laura was moving toward the west at 18 m.p.h. (30 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 1004 mb.

Tropical Storm Warnings were in effect for the U.S. Virgin Islands, Puerto Rico, Vieques and Culebra.  A Tropical Storm Warning was in effect for the northern coast of Hispaniola from Le Mole St. Nicholas, Haiti to Cabo Engano, Dominican Republic.  Tropical Storm Warnings were in effect for the Turks and Caicos, the Acklins, Long Key, Crooked Island, the Inaguas, and the Ragged Islands.  A Tropical Storm Warning was also in effect for the Cuban provinces of Las Tunas, Holguin, Santiago de Cuba, Guantanamo and Granma.

A Tropical Storm Watch was issued for the Florida Keys from Ocean Reef to Key West.  Tropical Storm Watches were in effect for the Central Bahamas and for Andros Island.

Tropical Storm Marco is forecast to move over HIspaniola and the mountains there are likely to disrupt the circulation.

TD 14 Strengthens into Tropical Storm Marco

Former Tropical Depression Fourteen strengthened into Tropical Storm Marco over the northwestern Caribbean Sea on Friday night.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Marco was located at latitude 18.7°N and longitude 84.9°W which puts it about 180 miles (290 km) southeast of Cozumel, Mexico.  Marco was moving toward the north-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1003 mb.

A Hurricane Watch was in effect for the portion of the coast from Punta Herrero to Cancun, Mexico.  A Tropical Storm Warning was in effect for the portion of the coast from Punta Herrero to Dzilam, Mexico.

An Air Force Reserve Hurricane Hunter reconnaissance aircraft found winds to tropical storm force in former Tropical Depression Fourteen and the National Hurricane Center upgraded the system to Tropical Storm Marco.  More thunderstorms developed near the center of Marco.  Many of the thunderstorms were occurring in short bands northeast of the center of circulation.  The strongest winds were occurring in those bands.  Storms near the center were generating upper level divergence which was pumping mass away to the northeast of the tropical storm.  Winds to tropical storm force extended 80 miles (130 km) to the northeast of Marco.  The winds in the other parts of the tropical storm were blowing at less than tropical storm force.

Tropical Storm Marco will move through an environment favorable for intensification during the next 24 hours.  Marco will move over water where the Sea Surface Temperature is near 29°C.  It will move east of a large upper level trough over the Gulf of Mexico.  The trough will produce southwesterly winds which will blow toward the top of Tropical Storm Marco.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification.  Marco will intensify on Saturday and it could strengthen quickly because the circulation is small.  Tropical Storm Marco could also weaken quickly if the center moves over the Yucatan Peninsula.

Tropical Storm Marco will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high and the upper level trough will interact to steer Marco toward the northwest during the next 24 to 36 hours.  On its anticipated track the center of Tropical Storm Marco could pass near the northeastern part of the Yucatan Peninsula on Saturday.

Elsewhere over the Atlantic Ocean, disorganized Tropical Storm Laura sped across the northern Leeward Islands on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Laura was located at latitude 17.0°N and longitude 84.9°W which put it about 195 miles (315 km) east-southeast of San Juan, Puerto Rico.  Laura was moving toward the west-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 1008 mb.

Tropical Storm Warnings were in effect Saba, St. Eustatius, St. Maarten, St. Martin, St. Barthelemy, the British Virgin Islands, the U.S. Virgin Islands, Puerto Rico, Vieques, Culebra, the north coast of HIspaniola from Le Mole St. Nicholas, Haiti to Cabo Engano, Dominican Republic, the Turks and Caicos, the Acklins, Crooked Island, Long Cay, the Inaguas, and the Ragged Islands.  A Tropical Storm Watch was in effect for the Central Bahamas.

Isaias Crosses Andros Island, Weakens to Tropical Storm

The center of former Hurricane Isaias crossed Andros Island on Saturday afternoon and it weakened to a tropical storm.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Isaias was located at latitude 25.1°N and longitude 78.7°W which put it about 115 miles (185 km) southeast of Ft. Lauderdale, Florida.  Isaias was moving toward the northwest at 10 m.p.h. (16 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 993 mb.

A Hurricane Warning was in effect for the portion of the coast from Boca Raton, Florida to the Flagler/Volusia County Line.  A Hurricane Waning was also in effect for the Northwestern Bahamas including Andros Island, New Providence, Eleuthera, the Abacos, the Berry Islands, Grand Bahama Island, and Bimini.

Tropical Storm Warnings were in effect for the portions of the coast from Ocean Reef to Boca Raton, Florida and from the Flagler/Volusia County Line to Ponte Vedra Beach, Florida.  A Tropical Storm Warning was also in effect for Lake Okeechobee.  A Tropical Storm Watch was in effect for the portion of the coast from Ponte Vedra Beach, Florida to South Santee River, South Carolina.

The center of former Hurricane Isaias crossed over Andros Island on Saturday afternoon.  Normally, Andros Island does not have much of an impact on hurricanes, but combined with a less favorable environment it contributed to a temporary weakening of Isaias.   Tropical Storm Isaias consisted primarily of bands of showers and lower clouds after crossing Andros Island.  However, new thunderstorms began to develop northeast of the center of circulation during the past several hours and part of the eyewall appeared to be reforming.  Bands in the western and southern parts of Isaias still consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation.

Tropical Storm Isaias will move through an environment somewhat favorable for intensification during the next 36 hours.  Isaias will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough over the central U.S. will produce westerly winds which blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, but they are likely to only affect the very top of the tropical storm.  Tropical Storm Isaias will move into a region where there is drier air in the middle and upper troposphere.  The circulation around Tropical Storm Isaias will reorganize and it is likely to strengthen back into a hurricane.

Tropical Storm Isaias will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Isaias toward the northwest during the next 24 hours.  Isaias will move more toward the north later on Sunday.  The upper level trough will turn Isaias toward the northeast on Monday.  On its anticipated track Tropical Storm Isaias is will approach the southeast coast of Florida near Ft. Lauderdale and West Palm Beach on Sunday.  Isaias is likely to be a hurricane when it approaches the coast.

Hurricane Isaias Forces Hurricane Warning for Florida

The threat posed by Hurricane Isaias forced the issuance of a Hurricane Warning for Florida on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Hurricane Isaias was located at latitude 22.6°N and longitude 75.7°W which put it about 195 miles (320 km) south-southeast of Nassau, Bahamas.  Isaias was moving toward the northwest 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 991 mb.

A Hurricane Warning was in effect for the portion of the coast from Boca Raton, Florida to the Volusia/ Brevard County Line.  Hurricane Warnings were also in effect for all of the Bahamas including the Acklins, Crooked Island, Long Cay, the Inaguas, Mayaguana, the Ragged Islands, Cat Island, the Exumas, Long Island, Rum Cay, San Salvador, Andros Island, New Providence, Eleuthera, the Abacos, the Berry Islands, Grand Bahama Island and Bimini.  Hurricane Watches were in effect for the portions of the coast from the Flagler/Volusia County Line to the Volusia/Brevard County Line and from Hallendale Beach to Boca Raton.  Tropical Storm Warnings were in effect for the Turks and Caicos, Ocean Reef to Boca Raton, Florida and Lake Okeechobee.  A Tropical Storm Watch was in effect for the portion of the coast from Flagler. Volusia County Line to Ponte Vedra, Florida.

The core of Hurricane Isaias exhibited greater organization on Friday afternoon.  Images from weather radar in the Bahamas and microwave sensors onboard satellites indicated that an eyewall was wrapping around the center of circulations.  The strongest winds were occurring in the ring of storms in the developing eyewall.  Storms near the center of Isaias were generating upper level divergence which was pumping mass away from the hurricane.  Bands of showers and thunderstorms were revolving around the core of Hurricane Isaias.  Winds to hurricane force extended out 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.

Hurricane Isaias will move through an environment favorable for intensification during the next 24 hours.  Isaias will move over water where the Sea Surface Temperature is 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 Isaias will strengthen on Saturday and it could intensify more rapidly once the inner core is fully formed.  Isaias could intensify into a major hurricane while it moves over the Bahamas.

Hurricane Isaias will move around the western end of a subtropical high pressure system over the North Atlantic Ocean.  The high will steer Isaias toward the northwest during the next 24 hours.  It will turn the hurricane more toward the north during the weekend when Isaias reaches the western end of the high pressure system.  On its anticipated track Hurricane Isaias will move over the Central Bahamas on Friday night.  Isaias could approach southeast Florida on Saturday.  Hurricane Isaias could approach the coast of the Carolinas on Monday.  Hurricane Isaias will bring strong winds to the southeast coast of Florida.  Those winds will blow the water toward the coast and they will create a dangerous storm surge.  Isaias will continue to produce strong winds and locally heavy rain in the Turks and Caicos and the Bahamas. Heavy rain could cause flash floods. Hurricane Isaias will also generate a dangerous storm surge in parts of the Bahamas.