Monthly Archives: August 2020

Typhoon Bavi Passes East of Shanghai

Typhoon Bavi passed east of Shanghai on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Bavi was located at latitude 31.9°N and longitude 124.7°E which put it about 200 miles (320 km) east-northeast of Shanghai, China.  Bavi was moving toward the north-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 958 mb.

The circulation around Typhoon Bavi was well organized on Tuesday.  A circular eye with a diameter of 18 miles (30 km) was at the center of Bavi.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Bavi.  Storm near the core generated upper level divergence which pumped mass away to the north of the typhoon.

The circulation around Typhoon Bavi was moderately large.  Winds to typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Bavi was 19.2.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 35.2.  Typhoon Bavi was capable of causing regional serious damage.

Typhoon Bavi will move through an environment favorable for intensification during the next 12 hours.  Bavi 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.  Typhoon Bavi could strengthen into the equivalent of a major hurricane during the next 12 hours.  In 12 hours Bavi will start to move over cooler water, which could end the chance for intensification.  In 24 hours Typhoon Bavi will approach the eastern part of an upper level trough over China.  The trough will produce strong southwesterly winds which will cause strong vertical wind shear.  The strong shear will cause Bavi to weaken more quickly.

Typhoon Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north during the next 36 hours.  On its anticipated track Typhoon Bavi could approach the west coast of North Korea in about 24 hours.  Bavi will bring strong winds and locally heavy rain to North Korea and parts of northeastern China.

Laura Strengthens into a Hurricane

Former Tropical Storm Laura strengthened into a hurricane on Tuesday morning.  At 8:15 a.m. EDT on Tuesday the center of Hurricane Laura was located at latitude 23.4°N and longitude 86.4°W which put it about 625 miles (1005 km) southeast of Lake Charles, Louisiana.  Laura was moving toward the west-northwest at 17 m.p.h. (28 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 Watch was in effect for the portion of the coast from San Luis Pass, Texas to Morgan City, Louisiana.  The Hurricane Watch includes Galveston, Texas.  Houston, Texas is under a Tropical Storm Watch.  Tropical Storm Watches are also in effect for the portions of the coast from Freeport to San Luis Pass, Texas and from Morgan City, Louisiana to the Mouth of the Mississippi River.

A Hurricane Hunter aircraft found on Tuesday morning that former Tropical Storm Laura had strengthened into a hurricane.  The distribution of thunderstorms around Laura was asymmetrical.  Many of the thunderstorms were occurring in bands in the southern half of the circulation and near the center of Laura.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the hurricane.  Winds to tropical storm force extended out 175 miles (280 km) on the eastern side of Laura.  Winds to tropical storm force extended out 100 miles (160 km) on the western side of the hurricane.

Hurricane Laura will move through an environment favorable for intensification during the next 30 hours.  Laura will move over water where the Sea Surface Temperature is near 30°C.  It will move under an upper level high where the upper level winds are weak.  There will be little vertical wind shear.  Hurricane Laura will continue to intensify.  When an inner core is fully formed with an eye and an eyewall, Laura could strengthen more rapidly.  Laura will likely strengthen into a major hurricane over the Gulf of Mexico.

Hurricane Laura will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Laura toward the west-northwest during the next 12 hours.  Laura will turn more toward the northwest as it approaches the western end of the high.  On its anticipated track the center of Hurricane Laura will approach the portion of the coast between Freeport, Texas and Lake Charles, Louisiana on Wednesday night.

Hurricane Laura is likely to be a major hurricane when it approaches the coast.  In addition to the strong winds, Laura could create a storm surge of over 10 feet (3 meters) along a portion of the coast. Heavy rain could also cause flash floods in some locations.

Tropical Storm Laura Prompts Hurricane Watch for Northwest Gulf Coast

The potential threat from Tropical Storm Laura prompted the issuance of a Hurricane Watch for a portion of the northwest Gulf Coast on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Laura was located at latitude 21.7°N and longitude 82.2°W which put it about 40 miles (65 km) east of the Isle of Youth, 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 1001 mb.

A Hurricane Watch was issued for the portion of the coast from Port Bolivar, Texas to Morgan CIty, Louisiana.  A Tropical Storm Watch was issued for the portion of the coast from Morgan City to the Mouth of the Mississippi River.  A Tropical Storm Warning remained in effect for the Florida Keys from Craig Key to Key West and the Dry Tortugas.  Tropical Storm Warnings were also in effect for the Cuban provinces of Ciego de Avila, Sancti Spiritus, Villa Carla, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar del Rio and Isle of Youth.

The appearance of Tropical Storm Laura did not change much on Monday afternoon.  Many of the stronger 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) from the center on the eastern side of Laura.  Winds were blowing at less than tropical storm force in the western half of the circulation.

Tropical Storm Laura will move near Cuba for another 12 to 18 hours.  So, the flow of air across Cuba is likely to continue to disrupt the northern half of the circulation during the time period.  When Laura moves over the Gulf of Mexico on Tuesday , it will move into an environment favorable for intensification.  Tropical Storm Laura will move over water where the Sea Surface Temperature is near 30°C.  It will move into an area where the upper level winds will be 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 strengthen into a major hurricane.

Tropical Storm Laura will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Laura toward the west-northwest during the next 12 to 24hours.  Laura will move more toward the north when it reaches the western end of the high.  On its anticipated track Tropical Storm Laura could make landfall on the northwest coast of the Gulf of Mexico on Wednesday night.  Laura could be a major hurricane when it makes landfall.

Elsewhere,  the center of Tropical Storm Marco was very close to the Mouth of the Mississippi River.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Marco was located at latitude 29.0°N and longitude 88.9°W which put it about 15 miles (25 km) east-southeast of the Mouth of the Mississippi River.  Marco was moving toward the northwest 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 1008 mb.  All coastal watches and warnings for Tropical Storm Marco have been discontinued.

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.

Typhoon Bavi Passes West of Okinawa

Typhoon Bavi passed west of Okinawa on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Bavi was located at latitude 27.2°N and longitude 125.6°E which put it about 595 miles (965 km) south-southwest of Chinhae, South Korea.  Bavi was moving toward the east-northeast at 4 m.p.h. (6 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 979 mb.

A circular eye developed at the center of Typhoon Bavi.  The eye was surrounded by a ring of strong thunderstorms.  Bands of showers and thunderstorms were revolving around the core of Bavi.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 45 miles from the center of circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center.

Typhoon Bavi will move through an environment favorable for intensification during the next 24 to 36 hours.  Bavi will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi will intensify during the next 36 hours and it could strengthen to the equivalent of a major hurricane.

Typhoon Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north during the next several days.  On its anticipated track Typhoon Bavi will pass west of the northern Ryukyu Islands.  Bavi could be southeast of South Korea in about 72 hours.

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.

Tropical Storm Bavi Forms East of Taiwan

Tropical Storm Bavi formed east of Taiwan on Friday night.  At 11:00 p.m. on Friday the center of Tropical Storm Bavi was located at latitude 23.9°N and longitude 122.8°E which put it about 85 miles (135 km) southeast of Taipei, Taiwan.  Bavi was moving toward the north-northeast 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 1000 mb.

The circulation around a low pressure system east of Taiwan strengthened on Friday night and the Japan Meteorological Agency designated the system as Tropical Storm Bavi.  The circulation around Bavi was asymmetrical.  Many of the thunderstorms were occurring in bands in the eastern half of the tropical storm.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the east of the tropical storm.  Winds to tropical storm force extended out 80 miles (130 km) to the east of the center of circulation.  The winds on the western side of Tropical Storm Bavi were blowing at less than tropical storm force.

Tropical Storm Bavi will move through an environment favorable for intensification during the next several days.  Bavi 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.  Tropical Storm Bavi will intensify and it could strengthen into a typhoon by the end of the weekend.

Tropical Storm Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north-northeast during the next few days.  On its anticipated track the center of Tropical Storm Bavi will pass west of the Ryukyu Islands including Okinawa.  Bavi could approach South Korea in about four days.  The eastern side of Bavi will bring gusty winds and locally heavy rain to the Ryukyu Islands.

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.

Tropical Storm Laura Develops, Warnings for Puerto Rico and Leeward Islands

Tropical Storm Laura developed east of the northern Leeward Islands on Friday morning.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Laura was located at latitude 17.0°N and longitude 60.2°W which put it about 210 miles (335 km) east-southeast of the northern Leeward Islands.  Laura was moving toward the west 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 1007 mb.

Tropical Storm Warnings were in effect for Saba, St. Eustatius, St. Maarten, Antigua, Barbuda, St. Kitts, Nevis, Anguilla, St. Martin, St. Barthelemy, the British Virgin Islands, the U. S, Virgin Islands, Puerto Rico, Vieques, and Culebra.

Tropical Storm Watches were in effect for the portion of the north coast of Hispaniola from Le Mole St. Nicholas, Haiti to Cabron, Dominican Republic and for the Turks and Caicos, the Acklins, Crooked Island, Long Cay, the Inaguas, and the Ragged Islands.

A NOAA plane found winds to tropical storm force in former Tropical Depression Thirteen on Friday morning and the National Hurricane Center upgraded the system to Tropical Storm Laura.  Even though the plane found winds to tropical storm force, the circulation around Tropical Storm Laura was not well organized. There were several clusters of thunderstorms in the northern half of the circulation, but there were fewer thunderstorms in the southern half of Laura.  Winds to tropical storm force extended out about 150 miles (240 km) on the northern side of the tropical storm.  The winds in the southern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Laura will move through an environment favorable for intensification during the next 24 hours.  Laura will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The lack of organization of the circulation around Laura will limit how quickly the tropical storm can intensify.  Tropical Storm Laura is likely to get stronger during the next 24 hours.

Tropical Storm Laura will move south of a subtropical high pressure system over the North Atlantic Ocean.  The high will steer Laura toward the west-northwest during the next several days.  On its anticipated track Tropical Storm Laura will move across the northern Leeward Islands later today.  Laura could reach Puerto Rico by Saturday.  Tropical Storm Laura will bring gusty winds and locally heavy rain to the islands when it passes over them.

Elsewhere, Tropical Depression Fourteen was getting more organized over the northwestern Caribbean Sea.  At 11:00 a.m. EDT on Friday the center of Tropical Depression Fourteen was located at latitude 16.6°N and longitude 84.1°W which put it about 325 miles (525 km) southeast of Cozumel, Mexico.  The depression was moving toward the northwest at 14 m.p.h. (22 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 1008 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 Bay Islands, Honduras and from Punta Herrero to Cancun, Mexico.  A Tropical Storm Watch was in effect for the portion of the coast from Cancun to Dzilam, Mexico.