Tag Archives: Northwestern Bahamas

Subtropical Storm Nicole Forms East of the Bahamas

Subtropical Storm Nicole formed east of the Bahamas on Monday morning. At 7:00 a.m. EST on Monday the center of Subtropical Storm Nicole was located at latitude 25.9°N and longitude 69.1°W which put it about 520 miles (835 km) east of the Northwestern Bahamas. Nicole was moving toward the north-northwest at 14 m.p.h. (22 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 1002 mb.

A Tropical Storm Watch was in effect for the Northwestern Bahamas.

A large low pressure system over the Atlantic Ocean east of the Bahamas exhibited more organization on Monday morning and the National Hurricane Center designated the system as Subtropical Storm Nicole. The circulation around Subtropical Storm Nicole exhibited a complex structure that is fairly common late in the hurricane season. The surface center of circulation was northeast of an upper level low east of Florida. The strongest winds near the surface were occurring far to the east of the surface center. Winds to tropical storm force extended out 275 miles (445 km) in the eastern side of Subtropical Storm Nicole. The winds in the western side of Nicole’s circulation were blowing at less than tropical storm force.

Subtropical Storm Nicole will move through an environment that is favorable for a gradual transition to a tropical storm. Nicole will move over water where the Sea Surface Temperatures are near 28˚C. The upper level low east of Florida will produce southerly winds that will blow across the top of the surface center of Subtropical Storm Nicole during the next 24 hours. Those winds will cause moderate vertical wind shear and the wind shear will inhibit intensification. Nicole will move into a region where the upper level winds are weaker on Tuesday and the wind shear will diminish. Subtropical Storm Nicole is likely to strengthen gradually during the next 24 hours. Nicole will move over warmer water when it moves over the Gulf Stream on Wednesday. Subtropical Storm Nicole is likely to make a transition to a tropical storm when it moves over the warmer water. Nicole could intensify to a hurricane when it moves over the warmer water.

The upper level low east of Florida will steer Subtropical Storm Nicole toward the northwest during the next 24 hours. A surface high pressure system currently over the Great Lakes will move over the East Coast of the U.S. and the western Atlantic Ocean. The high pressure system will block Nicole from moving toward the north. The high pressure system will steer Nicole toward the west-southwest on Tuesday and Wednesday. On its anticipated track Subtropical Storm Nicole could reach the Northwestern Bahamas on Wednesday morning. Nicole could reach the coast of Southeast Florida on Wednesday night. Nicole could be a hurricane when it reaches Florida. Nicole is likely to bring strong, gusty winds and locally heavy rain to the Northwestern Bahamas and southern Florida. The winds in the northern side of Nicole will blow water toward the coast of Florida and the Southeast U.S. Those winds will cause a storm surge and serious beach erosion when Nicole moves toward the coast.

Potential Tropical Cyclone One Drops Heavy Rain on South Florida

Potential Tropical Cyclone One dropped heavy rain on South Florida during Friday night and Saturday morning. There were reports of up to 10 inches of rain falling on locations in the area around Miami. The heavy rain caused urban and street flooding in some locations. At 8:00 a.m. EDT on Saturday the center of Potential Tropical Cyclone One was located at latitude 27.0°N and longitude 82.2°W which put it about 45 miles (75 km) south-southwest of Ft. Myers, Florida. Potential Tropical Cyclone One was moving toward the northeast at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1002 mb.

Tropical Storm Warnings were in effect for the coast of Florida from Bonita Beach on the west coast to the Volusia/Brevard County Line on the east coast and for all of the Florida Keys. Tropical Storm Warnings were also in effect for the Northwestern Bahamas and the Cuban provinces of Mayabeque, La Habana, Artemisa, and Pinar del Rio. Tropical Storm Watches were in effect for the Cuban provinces of Matanzas and the Isle of Youth.

Thunderstorms on the eastern side of Potential Tropical Cyclone One dropped heavy rain on parts of South Florida during Friday night and Saturday morning. A rain gauge at Biscayne Park measured 10.98 inches (27.9 cm) of rain. Media reports showed urban and street flooding in some locations.

The circulation around Potential Tropical Cyclone One remained poorly organized on Saturday morning. There was a broad area of low pressure over South Florida and the Southeastern Gulf of Mexico. The center of low pressure was located south-southwest of Naples, Florida. There was another circulation center located west-southwest of the Florida Keys. The strongest thunderstorms were occurring over South Florida and over the Northwestern Bahamas. The western half of Potential Tropical Cyclone One contained mainly showers and lower clouds. The strongest winds were occurring in thunderstorms in the eastern half of the low pressure system.

Potential Tropical Cyclone One will move through an environment that will be somewhat favorable for intensification when it moves over the Atlantic Ocean east of Florida on Sunday. Potential Tropical Cyclone One will move over water where the Sea Surface Temperatures are near 28˚C. An upper level trough over the Gulf of Mexico and an upper level ridge over the Northwest Caribbean Sea and western Atlantic Ocean will interact to produce southwesterly winds that will blow toward the top of Potential Tropical Cyclone One. Those winds will cause moderate vertical wind shear. The vertical shear will somewhat inhibit intensification. However, the upper level ridge will also enhance the upper level divergence over Potential Tropical Cyclone One. More upper level divergence would cause the surface pressure to decrease. Potential Tropical Cyclone One could strengthen to a tropical storm when it moves over the warm water in the Gulf Stream on Sunday.

The upper level trough over the Gulf of Mexico and the upper level ridge over the Northwest Caribbean Sea and western Atlantic Ocean will steer Potential Tropical Cyclone One toward the northeast during the next 36 hours. On its anticipated track, Potential Tropical Cyclone One will move across South Florida on Saturday. Potential Tropical Cyclone One will bring continue to drop heavy rain on parts of South Florida and the Northwestern Bahamas during Saturday. More heavy rain could cause flash floods in some locations.

Potential Tropical Cyclone One Produces Tropical Storm Force Winds

Potential Tropical Cyclone One produced tropical storm force winds over the southeastern Gulf of Mexico on Friday morning. Tropical Storm Warnings were in effect for South Florida, all of the Florida Keys, western Cuba and the Northwestern Bahamas. At 8:00 a.m. EDT on Friday the center of Potential Tropical Cyclone One was located at latitude 22.4°N and longitude 86.8°W which put it about 420 miles (675 km) southwest of Ft. Myers, Florida. Potential Tropical Cyclone One was moving toward the northeast at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1002 mb.

Tropical Storm Warnings were in effect for the coast of Florida from Longboat Key on the west coast to the Volusia/Brevard County Line on the east coast and for all of the Florida Keys. Tropical Storm Warnings were also in effect for the Northwestern Bahamas and the Cuban provinces of Mayabeque, La Habana, Artemisa, and Pinar del Rio. Tropical Storm Watches were in effect for the Cuban provinces of Matanzas and the Isle of Youth.

A U.S. Air Force Reserve Hurricane Hunter reconnaissance flight found that Potential Tropical Cyclone One was producing winds to tropical storm force over the southeastern Gulf of Mexico on Friday morning. The distribution of thunderstorms around Potential Tropical Cyclone One was asymmetrical due to vertical wind shear caused by an upper level trough over the western Gulf of Mexico. The strongest thunderstorms were occurring in a band in the eastern half of Potential Tropical Cyclone One. Those thunderstorms generated upper level divergence that pumped mass to the east of the system. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 60 miles (95 km) in the eastern half of Potential Tropical Cyclone One. The winds in the western half of the circulation were blowing at less than tropical storm force.

Potential Tropical Cyclone One will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Potential Tropical Cyclone One will move over water where the Sea Surface Temperatures are near 28˚C. The upper level trough over the western Gulf of Mexico and an upper level ridge over the Northwest Caribbean Sea will interact to produce southwesterly winds that will blow toward the top of Potential Tropical Cyclone One. Those winds will cause moderate vertical wind shear. The vertical shear will somewhat inhibit intensification. However, the upper level ridge will also enhance the upper level divergence over Potential Tropical Cyclone One. More upper level divergence would cause the surface pressure to decrease. Potential Tropical Cyclone One is forecast to strengthen to a tropical storm during the next 24 hours.

The upper level trough over the western Gulf of Mexico and the upper level ridge over the Northwest Caribbean Sea will steer Potential Tropical Cyclone One toward the northeast during the next several days. On its anticipated track, Potential Tropical Cyclone One will approach Southwest Florida on Saturday morning. Potential Tropical Cyclone One will bring gusty winds and heavy rain to South Florida, the Florida Keys, western Cuba and the Northwestern Bahamas. Heavy rain is likely to cause flash floods in some locations.

Dangerous Hurricane Dorian Nears Northwestern Bahamas

Dangerous Hurricane Dorian neared the Northwestern Bahamas on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Hurricane Dorian was located at latitude 26.3°N and longitude 75.1°W which put it about 125 miles (200 km) east of Great Abaco and about 310 miles (500 km) east of West Palm Beach, Florida.  Dorian was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h)  and there were wind gusts to 185 m.p.h. (315 km/h).  The minimum surface pressure was 940 mb.

Hurricane Warnings were in effect for the Northwestern Bahamas including the Abacos, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.  A Hurricane Watch was in effect for Andros Island.  A Tropical Storm Watch has been issued for the portion of the coast from Deerfield Beach to Sebastian Inlet, Florida.

Hurricane Dorian remains a very dangerous, well organized storm.  Dorian has maintained Category 4 intensity on the Saffir-Simpson Scale for 24 hours.  A circular eye with a diameter of 15 miles (24 km) was clearly visible on conventional and microwave satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  The maximum sustained wind speed at the surface was 150 m.p.h. (240 km/h) and data from dropsondes indicated that the wind was stronger a few hundred feet above the surface.  Bands of showers and thunderstorms were revolving around the core of Hurricane Dorian.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.

Winds to hurricane force extended out about 30 miles (50 km) from the center of Hurricane Dorian.  Winds to tropical storm force extended out about 105 miles (170 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Dorian was 33.3.  The Hurricane Size Index (HSI) was 11.7and the Hurricane Wind Intensity Size Index (HWISI) was 45.0.  Hurricane Dorian is capable of causing regional significant damage.

Hurricane Dorian will remain in an environment capable of supporting a very strong hurricane for several more days.  Dorian 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.  There will be a potential for Hurricane Dorian to strengthen to Category 5 on the Saffir-Simpson Scale.  At some point eyewall replacement cycles are likely to cause fluctuations in intensity.

Hurricane Dorian will move around the western end of a subtropical high pressure system during the next 24 to 48 hours.  The high will steer Dorian slowly toward the west.  Hurricane Dorian could move very slowly when it reaches the western end of the ridge.  Eventually, Dorian will turn toward the north when it moves around the end of the ridge.  On its anticipated track Hurricane Dorian will reach the Northwestern Bahamas by Sunday evening.  The core of Dorian will move very close to the Abacos and Grand Bahama Island.  Hurricane Dorian could cause significant wind damage.  Dorian could also produce a storm surge of up to 15 feet (4.5 meters) in places where the wind blows water toward the shoreline.