Tag Archives: Nassau

Depression Strengthens to Tropical Storm Imelda

Former Tropical Depression Nine strengthened to Tropical Storm Imelda over the Bahamas on Sunday afternoon.  At 2:00 p.m. EDT on Sunday the center of Tropical Storm Imelda was located at latitude 23.9°N and longitude 77.3°W which put the center about 105 miles (165 km) south of Nassau, Bahamas.   Imelda was moving toward the north at 7 m.p.h. (11 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 998 mb.

Tropical Storm Warnings were in effect for the Central Bahamas including Cat Island, the Exumas, Long Island, Rum Cay, and San Salvador.

Tropical Storm Warnings were in effect for the Northwestern Bahamas including Eleuthera, New Providence, the Abacos, the Berry Islands, Andros Island, and Grand Bahama Island.

A Tropical Storm Watch was in effect for the portion of the coast from the Palm Beach/Martin County Line to the Flagler/Volusia County Line, Florida.

A U.S. Air Force Reserve Hurricane Hunter reconnaissance plane found on Sunday afternoon that former Tropical Depression Nine had strengthened.  Based on data collected by the reconnaissance plane, the U.S. National Hurricane Center designated the system as Tropical Storm Imelda.

More thunderstorms were forming near the center of Tropical Storm Imelda on Sunday afternoon.  However, the distribution of thunderstorms in Imelda was asymmetrical.  Thunderstorms were occurring mainly in bands in the eastern side of Imelda’s circulation.  Bands in the western side of Tropical Storm Imelda consisted primarily of showers and lower clouds.

Winds to tropical storm force extended out 30 miles (50 km) from the center of Tropical Storm Imelda.

Tropical Storm Imelda will move through an environment favorable for intensification during the next 24 hours.  Imelda will move over water where the Sea Surface Temperatures are near 29°C.   It will move under the eastern side of an upper level trough that is west of Florida.  The upper level trough will produce southerly winds that will blow toward the top of Imelda”s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Imelda will intensify during the next 24 hours.

The upper level trough west of Florida will steer Tropical Storm Imelda toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Imelda will move across the Central and Northwestern Bahamas.

Tropical Storm Imelda will bring strong winds and locally heavy rain to the Central and Northwestern Bahamas.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Atlantic Ocean, powerful Hurricane Humberto was passing south of Bermuda.  At 11:00 a.m. EDT on Sunday the center of Hurricane Humberto was located at latitude 24.6°N and longitude 64.3°W which put the center about 535 miles (855 km) south of Bermuda.  Humberto was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 180 m.p.h. (290 km/h).  The minimum surface pressure was 934 mb.

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.

Tropical Storm Philippe Brings Wind, Rain to Cuba and South Florida

Tropical Storm Philippe brought wind and rain to parts of Cuba and south Florida on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Philippe was located at latitude 24.8°N and longitude 82.1°W which put it about 25 miles (40 km) northwest of Key West, Florida.  Philippe was moving toward the north-northeast at 24 m.p.h. (39 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.

Tropical Storm Warnings were in effect for the Cuban provinces of Isla de la Juventud, La Habana, Ciudad de la Habana, Matanzas, Cienfuegos and Villa Clara.  Tropical Storm Warnings were in effect for the northwestern Bahamas including the Abacos, Andros Island, Berry Island, Bimini, Eleuthera, Grand Bahama Island and New Providence.  Tropical Storm Watches were in effect for the portion of the coast from Craig Key to Golden Beach, Florida.  Tropical Storm Watches were also in effect for the Central Bahamas including Cat Island, the Exumas, Long Island, Rum Cay and San Salvador.

The circulation is of Tropical Storm Philippe is not well organized.  The appear to be multiple smaller centers of counterclockwise rotation moving around inside the broader circulation.  One center of circulation is in northwest of Key West.  Showers and thunderstorms were primarily northeast of that center of rotation.  There were low clouds west of that center.  Another center of rotation was just north of the coast of Cuba.  A primary band of showers and thunderstorms wrapped around the eastern side of this second center.  The middle and upper level circulation of Tropical Storm Philippe appeared to be associated with the center near Cuba.

Tropical Storm Philippe will move through an environment that will be somewhat favorable for intensification.  Philippe will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough approaching Tropical Storm Philippe from the west is producing strong southwesterly winds which are causing significant vertical wind shear.  The shear is inhibiting the organization of the circulation.  Tropical Storm Philippe could intensify on Sunday if the center of circulation near Cuba becomes the dominant center, since it has a more complete vertical structure.

The upper level trough will continue to steer Tropical Storm Philippe quickly toward the northeast on Sunday.  On its anticipated track Tropical Storm Philippe will move through the Upper Florida Keys and over the Northwestern Bahamas on Sunday.   It will bring gusty winds and locally heavy rains to those areas.

Potential Tropical Cyclone Eighteen Prompts Warnings for Cuba and Bahamas

Potential Tropical Cyclone Eighteen prompted the governments of Cuba and the Bahamas to issue Tropical Storm Warnings and Watches for portions of those countries on Friday afternoon.  At 5:00 p.m. EDT on Friday the center of Potential Tropical Cyclone Eighteen was located at latitude 17.5°N and longitude 84.5°W which put it about 415 miles (670 km) south-southwest of Havana, Cuba.  It was moving toward the north-northwest at 6 m.p.h. (10 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 1006 mb.

Tropical Storm Warnings were issued for the Cuban provinces of Isla de la Juventud, La Habana, Ciudad de la Habana, Matanzas, Cienfuegos, and Villa Clara.  Tropical Storm Warnings were also issued for the northwestern Bahamas including the Abacos, Andros Island, Berry Island, Bimini, Eleuthera, Grand Bahama Island and New Providence.  Tropical Storm Watches were issued for the Central Bahamas including Cat Island, the Exumas, Long Island, Rum Cay and San Salvador.

An Air Force Reserve Hurricane Hunter reconnaissance plane investigated the system formerly known as Invest 93L on Friday afternoon.  The plane found sustained winds to tropical storm force.  The plane also found a broad circulation center with several smaller centers of circulation revolving around inside the broader center.  Based on the observations from the plane, the National Hurricane Center (NHC) chose not to upgrade the system to Tropical Storm Philippe in its 5:00 p.m. EDT advisory.  However, NHC did change the designation of the system from Invest 93L to Potential Tropical Cyclone Eighteen.  If a more well defined center of circulation develops, then NHC could still change designation of the system to Tropical Storm Philippe.

The circulation of Potential Tropical Cyclone Eighteen is still organizing.  As mentioned above, there is a broad center of counterclockwise rotation.  There are also several smaller counterclockwise swirls within the broader center.  More showers and thunderstorms developed closer to the center of circulation on Friday afternoon.  The storms closer to the center of circulation were generating some upper level divergence which was pumping away mass to the northeast of the system.  Some bands of showers and thunderstorms were developing in the outer portions of the circulation.

Potential Tropical Cyclone Eighteen will move through an environment somewhat favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The system is embedded in a flow over warm moist air.  However there is a stationary front northwest of the system and there is cooler, drier air north of the stationary front.  The system is currently under the western side of an upper level ridge.  The upper level winds are weak and there is not much vertical wind shear.  Potential Tropical Cyclone Eighteen could slowly intensify during the next 24 hours as the circulation becomes more well organized.

The ridge east of Potential Tropical Cyclone Eighteen is steering the system toward the north-northwest.  That general motion should continue for another six to twelve hours.  An upper level trough will approach the system from the west on Saturday and the trough will start to steer it more toward the northeast.  On its anticipated track Potential Tropical Cyclone Eighteen will approach Cuba on Saturday afternoon.  The center of the system will move south of the Florida Keys on Saturday night and it could move across the northwestern Bahamas on Sunday.

The system will bring gusty winds and locally heavy rain to those locations.  The locally heavy rain could cause flooding.  There could be a storm surge of several feet (one to two meters) on parts of the south coast of Cuba, where the wind blows the water toward the coast.  There could also be some storm surge along the coasts of the Florida Keys.