Tag Archives: Tropical Storm Marco

Tropical Storm Marco Weakens Near Louisiana

Tropical Storm Marco weakened near Louisiana on Monday morning.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Marco was located at latitude 28.5°N and longitude 88.5°W which put it about 55 miles (90 km) southeast of the Mouth of the Mississippi River.  Marco was moving toward the north-northwest at 8 m.p.h. (13 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 1006 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Morgan City, Louisiana to the Mississippi/Alabama border including New Orleans, Lake Pontchartrain and Lake Maurepas.

An upper level trough over Texas produced strong southwesterly winds which sheared the top off of Tropical Storm Marco on Monday morning.  Stronger thunderstorms were confined to a few bands northeast of the center of circulation.  Bands around the center and in other parts of Marco consisted of showers and lower clouds.  Winds to tropical storm force were only occurring in the thunderstorms northeast of the center.

Since the wind shear is expected to continue, the circulation around Tropical Storm Marco is expected to spin down.  As Marco weakens it will be steer more by the winds in the lower atmosphere.  A subtropical high pressure system over the Atlantic Ocean is expected to expand to the west during the next several days.  The high will turn the low level circulation of Tropical Storm Marco more toward the west.  On its anticipated track Tropical Storm Marco will make landfall over southeastern Louisiana on Monday night.  Marco will bring gusty winds and some rain, but its impact is likely to be minor.

Elsewhere, Tropical Storm Laura was moving near the south coast of Cuba.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Laura was located at latitude 21.2°N and longitude 80.6°W which put it about 65 miles east-southeast of Cayo Largo, Cuba.  Laura was moving toward the west-northwest at 20 m.p.h. (32 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 1002 mb.

Tropical Storm Warnings were in effect for the Florida Keys from Craig Key to Key West and for the Dry Tortugas.  Tropical Storm Warnings were in effect for Little Cayman and Cayman Brac.  Tropical Storm Warnings were also in effect for the Cuban provinces of Camaguey, Las Tunas, Ciego De Avila, Sancti Spiritus, Villa Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar Del Rio and Isle of Youth.

The circulation around Tropical Storm Laura was not as well organized on Monday morning.  Passage of Hispaniola and eastern Cuba disrupted the northern half of the circulation.  The strongest thunderstorms were occurring in bands in the southern half of the circulation.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 175 miles (280 km) on the eastern side of Laura.  The winds on the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Laura will move near the south coast of Cuba for another 18 hours.  Since nearly half the circulation will be blowing across Cuba, it will continue to disrupt the northern half of the tropical storm.  Laura will move over the Gulf of Mexico on Tuesday.  When Tropical Storm Laura reaches the Gulf, it will move into a very favorable environment.  Laura will move over water where the Sea Surface Temperature is near 30°C.  It will move into a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Laura will intensify into a hurricane over the Gulf of Mexico and it could rapidly strengthen into a major hurricane.  Laura is expected to move over the northwestern Gulf of Mexico on Wednesday.

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.