Tag Archives: Key West

Tropical Storm Gordon Forms, Causes Warnings for South Florida

Former Potential Tropical Cyclone Seven developed a distinct center of circulation on Sunday morning and the National Hurricane Center upgraded the system to Tropical Storm Gordon.  At 8:30 a.m. EDT on Sunday the center of Tropical Storm Gordon was located at latitude 25.1°N and longitude 80.6°W which put it about 10 miles (15 km) west of Key Largo, Florida.  Gordon was moving toward the west-northwest at 16 m.p.h. (26 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 1009 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Golden Beach to Bonita Beach, Florida.  A Tropical Storm Warning was in effect for the Florida Keys from Craig Key to Ocean Reef including Florida bay.  A Tropical Storm Warning was in effect for the portion of the coast from the Alabama-Florida border to Morgan City, Louisiana including Lake Pontchartrain.

The circulation of Tropical Storm Gordon became much better organized during the past 12 hours.  A distinct low level center of circulation formed and many more thunderstorms developed.  A C-MAN station on Fowey Rock, Florida reported sustained winds of 49 m.p.h. (80 km/h) supporting the designation as a tropical storm.  The circulation of Tropical Storm Gordon was still organizing.  More thunderstorms were developing in bands northeast of the center of circulation than in other parts of the tropical storm.  Those storms were beginning to generate upper level divergence which was pumping mass away from the core of Gordon.

Tropical Storm Gordon will be moving through an environment favorable for intensification during the next 36 hours.  Gordon will be moving over water where the Sea Surface Temperature is near 30°C.  It will be moving through a region where the upper level winds will be weak and there will be little vertical wind shear.  Tropical Storm Gordon will continue to intensify and it could intensify more rapidly once the inner core becomes better organized.  There is a chance that Gordon could strengthen into a hurricane before it reaches the north coast of the Gulf of Mexico.

Tropical Storm Gordon will move around the west end of a subtropical high pressure system over the western Atlantic Ocean.  The ridge will steer Gordon in  a general west-northwesterly direction.  On its anticipated track Tropical Storm Gordon will move away from South Florida later today.  Gordon could approach the north coast of the Gulf of Mexico late on Tuesday.  Locally heavy rain could cause floods in South Florida.  Tropical Storm Gordon could produce a storm surge of 6 to 9 feet (2 to 3 meters) along parts of the northern Gulf Coast.

Potential Tropical Cyclone Seven Causes Tropical Storm Watch for U.S. Gulf Coast

Potential Tropical Cyclone Seven caused the National Hurricane Center to issue a Tropical Storm Watch for a portion of the U.S. Gulf Coast on Sunday afternoon.  A Tropical Storm Watch was in effect for the portion of the coast from the Alabama-Florida border to Morgan City, Louisiana including Lake Pontchartrain.  At 5:00 p.m. EDT on Sunday the center of Potential Tropical Cyclone Seven was located at latitude 22.7°N and longitude 77.3°W which put it about 275 miles (445 km) east-southeast of Marathon, Florida.  It was moving toward the west-northwest at 15 m.p.h (24 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1012 mb.

Bands of showers and thunderstorms began to form in a tropical wave over the Bahamas and the National Hurricane Center designated the system as Potential Tropical Cyclone Seven in order to be able to issue the Tropical Storm Watch for the north coast of the Gulf of Mexico.  The circulation of Potential Tropical Cyclone Seven was still organizing.  A distinct low level center of circulation had not formed.  Bands of showers and thunderstorms were developing and the bands were starting to revolve around the inner part of the weather system.  Thunderstorms were beginning to generate some upper level divergence.

Potential Tropical Cyclone Seven will be moving into an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge is forecast to develop over Potential Tropical Cyclone Seven.  If that occurs, then the upper level winds would be weak and there would be little vertical wind shear.  Potential Tropical Cyclone Seven is forecast to intensify into Tropical Storm Gordon.  If the system moves slowly enough, there is a chance it could strengthen into a hurricane before it reaches the Gulf Coast.

Potential Tropical Cyclone Seven will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Potential Tropical Cyclone Seven in a general west-northwesterly direction.  On its anticipated track the system will move over the Florida Keys on Monday.  It will be over the eastern Gulf of Mexico on Tuesday and the system could reach the northern Gulf Coast late on Tuesday or early on Wednesday.

Elsewhere over the tropical Atlantic, Tropical Storm Florence was moving quickly away from the Cabo Verde Islands.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Florence was located at latitude 17.4°N and longitude 34.6°W which put it about 700 miles (1125 km) west of the Cabo Verde Islands.  Florence was moving toward the west-northwest at 15 m.p.h. (24 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 1000 mb.

Subtropical Storm Alberto Moves Into the Gulf of Mexico

Subtropical Storm Alberto moved over the southeastern Gulf of Mexico on Saturday.  At 11:00 p.m. EDT on Saturday the center of Subtropical Storm Alberto was located at latitude 23.9°N and longitude 84.6°W which put it about 120 miles (195 km) west-southwest of the Dry Tortugas.  Alberto was moving toward the north-northeast 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 1001 mb.

Tropical Storm Warnings were in effect for the Dry Tortugas and the portions of the coast from Bonita Beach to Anclote River and from the Aucilla River to the border between Alabama and Mississippi.  A Tropical Storm Watch was in effect from the border between Alabama and Mississippi to the Mouth of the Pearl River.

The circulation of Subtropical Storm Alberto remained poorly organized on Saturday.  Several low level centers dissipated and new low level centers of circulation developed on the southwestern edge of an area of thunderstorms northeast of the center.  Even though the center of circulation reorganized several times, the pressure did decrease slowly during the day.  The strongest wind speeds were occurring in the area of thunderstorms northeast of the center of circulation.  The winds were weaker south and west of the center.

Subtropical Storm Alberto will move through an environment that will become more favorable for intensification during the next 48 hours.  Alberto will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough over the western Gulf of Mexico was producing southwesterly winds which were blowing across the top of the circulation.  Those winds were causing significant vertical wind shear which was inhibiting the intensification of Subtropical Storm Alberto.  The shear was also preventing thunderstorms from persisting near the center of circulation, which was keeping Alberto from making a transition to a tropical storm.  An upper level ridge was forming over Florida.  The ridge was starting to enhance upper level divergence to the east of Subtropical Storm Alberto.

The upper level trough will gradually evolve into a closed upper level low.  The vertical wind shear will slowly decrease during the next several days.  When the shear decreases, it will allow Subtropical Storm Alberto to strengthen.  Less vertical wind shear will also let thunderstorms persist closer to the center of circulation.  If thunderstorms persist near the center, then Alberto could exhibit the structure of a tropical cyclone and it could be designated as a tropical storm.  Subtropical Storm Alberto could intensify into a hurricane over the northern Gulf of Mexico.

The reformations of the low level center of circulation increase the uncertainty of track forecasts.  The upper level trough is likely to steer Subtropical Storm Alberto toward the north on Sunday.  Alberto could turn more toward the north-northwest when the trough changes into an upper level low.  On its anticipated track Subtropical Storm Alberto could approach the coast of the northern Gulf of Mexico within 48 hours.  Alberto could be a strong tropical storm or a hurricane at that time.

Subtropical Storm Alberto will be capable of causing minor wind damage when it makes landfall.  Alberto will drop locally heavy rain north and east of the center of circulation.  Flood Watches have been issued for several states in the southeastern U.S.  The Gulf Coast is very susceptible to storm surge.  There will be increases in the water level along the eastern and northern Gulf Coast where the winds blow water toward the shore.

Subtropical Storm Alberto Forms Over Northwest Caribbean Sea

Subtropical Storm Alberto formed over the northwestern Caribbean Sea on Friday morning.  The National Hurricane Center (NHC) designated an area of low pressure as Subtropical Storm Alberto on Friday morning based on data from buoys and ship reports.  At 5:00 p.m. EDT on Friday the center of Subtropical Storm Alberto was located at latitude 19.4°N and longitude 86.3°W which put it about 85 miles (135 km) south-southeast of Cozumel, Mexico.  Alberto was moving toward the east at 2 m.p.h. (3 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 1005 mb.

A Tropical Storm Watch has been issued for the portion of the U.S. coast from Indian Pass, Florida to Grand Isle, Louisiana including New Orleans.  The government of Mexico issued a Tropical Storm Watch for the portion of the coast from Tulum to Cabo Catoche.  The government of Cuba issued a Tropical Storm Watch for the province of Pinar del Rio.

The circulation around Subtropical Storm Alberto was asymmetrical.  The low level center of circulation was located just to east of the Yucatan Peninsula.  The strongest thunderstorms were occurring in a band located about 100 miles (160 km) east and north of the center.  Flow around an upper level trough over the Gulf of Mexico was producing westerly winds which were blowing toward the top of the circulation.  Those winds were causing strong vertical wind shear which was the reason why the thunderstorms were occurring well to the east of the center of circulation.

Subtropical Storm Alberto will move through an environment marginally favorable for intensification during the next 24 to 36 hours.  Alberto will move over water where  the Sea Surface Temperature is near 28°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, the upper level trough will continue to cause moderate to strong vertical wind shear during the next day or so.  The wind shear will inhibit intensification.  Some gradual strengthening is possible.  The winds are weaker near the axis of the upper level trough.  If Alberto moves under the axis of the trough when it reaches the northern Gulf of Mexico, then the wind shear will decrease.  Alberto could strengthen more quickly if that happens.  There is a chance that Alberto could reach hurricane intensity.  If more thunderstorms form closer to the center of circulation, then NHC could change the designation of Alberto to a tropical storm.

Subtropical Storm Alberto is moving around the western end of a large high pressure system over the Atlantic Ocean.  The high is steering Alberto slowly toward the north-northeast.  A general motion toward the north is forecast during the next day or so.  When Alberto gets farther north, the upper level trough could steer it more toward the north-northwest.  There is a chance that the steering currents could weaken when Alberto nears the Gulf Coast.  Thus, there is much more uncertainty about the track forecast after that time.

The greatest risk with Subtropical Storm Alberto will be locally heavy rain and the potential for flooding.  Most of the heavy rain is likely to fall north and east of the center.  Much less rain is likely to fall from the western side of Alberto.  The coast of the Gulf of Mexico is very susceptible to storm surges.  The water level will rise along the eastern and northern coasts of the Gulf of Mexico where the winds blow the water toward the shoreline.

Cyclone Likely to Form Over Gulf of Mexico

A cyclone is likely to form over the Gulf of Mexico during the upcoming weekend.  A broad area of low pressure at the surface is currently centered over the Yucatan Peninsula.  The area of low pressure is currently designated as Invest 90L.  The circulation around the low pressure system is not well organized at the current time.  The center of the surface low is over the Yucatan Peninsula.  Showers and lower clouds are occurring near the center of the low.  Stronger thunderstorms are occurring on the eastern side of the low over the northwestern Caribbean Sea.  Sustained winds of 20 m.p.h. to 30 m.p.h. (30 km/h to 50 km/h) were blowing across the northwestern Caribbean Sea.  The winds were weaker over land near the center of circulation.

An upper level trough over the Gulf of Mexico was producing strong westerly winds which were blowing over the top of the surface low.  Those winds were causing strong vertical wind shear and the wind shear was one of the reasons why the stronger thunderstorms were occurring east of the center of circulation.  Sinking motion in the western portion of the upper level trough was bringing drier air to the surface and the drier air was inhibiting the formation of thunderstorms in the western side of the surface low.

The National Hurricane Center (NHC) indicated in a Special Tropical Weather Outlook at 2:00 p.m. EDT on Thursday that there is a 70% probability of the formation of a subtropical or tropical depression during the next 48 hours.  NHC has tentatively tasked a reconnaissance aircraft to investigate the low pressure system on Friday afternoon if necessary.

The wind speeds are slower near the axis of the upper level trough.  If the surface low pressure system moves under the axis of the upper level trough, then there would be less vertical wind shear and a cyclone could form.  If thunderstorms develop near the center of circulation after the center moves over the northwestern Caribbean Sea or southeastern Gulf of Mexico, then NHC would likely designate the system as a tropical depression.  If the thunderstorms develop farther away from the center of circulation and the circulation does not exhibit a tropical appearance, then NHC could classify the system as a subtropical depression.  NHC would issue advisories on the cyclone even if it is designated a subtropical depression.

There is a strong high pressure system over the Atlantic Ocean and the high is likely to steer the surface low toward the north.  The Sea Surface Temperature of the water in the southeastern Gulf of Mexico is near 27°C.  So, there is enough energy to support the formation of a tropical cyclone.  Most of the stronger thunderstorms are likely to continue to form in the eastern side of the circulation because of the vertical wind shear and drier air to the northwest of the surface low.  The low pressure system could slowly organize into a tropical storm during the weekend.

Heavy rain and the potential for flooding are the greatest risks with this low pressure system.  There will be some storm surge along the eastern and northern coasts of the Gulf of Mexico as counterclockwise rotation around the low blows water toward the shore.

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.