Monthly Archives: August 2021

Tropical Storm Ida Strengthens

Reconnaissance planes found Friday morning that Tropical Storm Ida had strengthened over the Northwest Caribbean Sea. At 8:00 a.m. EDT on Friday the center of Tropical Storm Ida was located at latitude 20.3°N and longitude 81.7°W which put it about 115 miles (185 km) southeast of the Isle of Youth, Cuba. Ida was moving toward the northwest at 15 m.p.h. (24 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 996 mb.

A Hurricane Watch was in effect for the portion of the coast from Cameron, Louisiana to the Mississippi/Alabama border. The Hurricane Watch included New Orleans, Lake Ponchartrain and Lake Maurepas. Tropical Storm Warnings were in effect for the Cayman Islands. Tropical Storm Warnings were also in effect for the Cuban provinces of Matanzas, Mayabeque, Havana, Artemisa, Pinar del Rio and the Isle of Youth. A Tropical Storm Watch was in effect for the portion of the coast from the Mississippi/Alabama border to the Alabama/Florida border.

Two reconnaissance planes flying through Tropical Storm Ida on Friday morning found that the sustained wind speed had increased and the minimum surface pressure had decreased. The planes also found that the circulation around Ida was more organized.  Thunderstorms were forming near the center of Ida.  Storms near the center of circulation were generating upper level divergence that pumped mass away from the tropical storm.  The removal of mass was causing the surface pressure to decrease.  The decreasing pressure resulted in the generation of more force which produced higher wind speeds.  More thunderstorms were also forming in bands revolving around the center of Tropical Storm Ida. Winds to tropical storm force extended out 80 miles (130 km) from the center of Ida.

Tropical Storm Ida will move into an environment that will become increasingly favorable for intensification during the next 48 hours.  An upper level low over the southeast U.S. was producing southerly winds that were blowing toward the top of Ida’s circulation.  Those winds were causing some vertical wind shear.  However, the upper low was moving away from Ida and the low was weakening.  The wind shear will decrease as the upper low weakens.  Tropical Storm Ida will move over water where the Sea Surface Temperature is near 30˚C.  Ida will continue to intensify today.  Tropical Storm Ida could strengthen to a hurricane during the next 24 hours. Ida will move across western Cuba this evening, which could briefly slow the intensification process.  An upper level ridge will be over the Gulf of Mexico during the weekend.  The winds will be weak in the ridge and there will be little vertical wind shear.  Ida is likely to undergo a period of rapid intensification during the weekend that will cause it to strengthen to a major hurricane.  Ida could reach Category 4 on the Saffir-Simpson Scale on Sunday.

Tropical Storm Ida will move around the southwestern part of a high pressure system that extended from the Atlantic Ocean to the eastern Gulf of Mexico.  The high will steer Ida toward the northwest during the next 48 hours.  As mentioned above, on its anticipated track Tropical Storm Ida will move across western Cuba on Friday evening. Ida will bring gusty winds and locally heavy rain to western Cuba. Ida is likely to approach the coast of Louisiana as a major hurricane on Sunday.  Ida will be capable of causing major damage when it approaches the coast. It could cause a storm surge of up to 10 to 14 feet (3 to 4 meters). A Storm Surge Watch has been issued for the coast from Sabine Pass to the Alabama/Florida border. The Storm Surge Watch includes Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay. Ida probably will not be as strong or as large as Hurricane Laura was last year.  Ida could be a little bigger and a little stronger than Hurricane Delta was when it approached Louisiana in 2020.

Tropical Storm Ida Prompts Hurricane Watch for Louisiana and Mississippi

The threat posed by Tropical Storm Ida prompted the issuance of a Hurricane Watch for the coast of Louisiana and Mississippi on Thursday night. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Ida was located at latitude 18.6°N and longitude 80.5°W which put it about 65 miles (105 km) southeast of Grand Cayman. Ida was moving toward the northwest at 12 m.p.h. (19 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. (65 km/h). The minimum surface pressure was 1006 mb.

A Hurricane Watch was issued for the portion of the coast from Cameron, Louisiana to the Mississippi/Alabama border. The Hurricane Watch included New Orleans, Lake Ponchartrain and Lake Maurepas. Tropical Storm Warnings were in effect for the Cayman Islands. Tropical Storm Warnings were also in effect for the Cuban provinces of Matanzas, Mayabeque, Havana, Artemisa, Pinar del Rio and the Isle of Youth. A Tropical Storm Watch was in effect for the portion of the coast from the Mississippi/Alabama border to the Alabama/Florida border.

The circulation around Tropical Storm Ida was gradually becoming more organized. A few more thunderstorms were beginning to develop near the center of Ida. A rainband was wrapping around the eastern and northern sides of the center of circulation. However, the distribution of thunderstorms was still asymmetrical. The strongest thunderstorms were occurring in bands forming on the eastern side of Tropical Storm Ida. An upper level low near Florida was producing south-southwesterly winds that were blowing over the western side of Ida’s circulation. Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms. Wind to tropical storm force extended out 70 miles (110 km) in the northeastern quadrant of Tropical Storm Ida. The winds in the other parts of Ida’s circulation were blowing at less than tropical storm force.

Tropical Storm Ida will move around the southwestern part of a subtropical high pressure system over the Atlantic Ocean during the next several days. The high will steer Ida toward the northwest. On its anticipated track Tropical Storm Ida will move over the Cayman Islands during the next few hours. Ida could be near western Cuba on Friday evening. Tropical Storm Ida will bring gusty winds and locally heavy rain to the Cayman Islands and parts of western Cuba. Ida will move over the Gulf of Mexico during the weekend. It could approach the central coast of the Gulf of Mexico on Sunday.

Tropical Storm Ida will move into an environment that will become more favorable for intensification during the next 60 hours. The upper low near Florida will move off to the northwest and it will weaken. When the upper low weakens, they vertical wind shear will decrease. Ida will move over water where the Sea Surface Temperatures are near 30°C. Ida is likely to strengthen to a hurricane during the next 36 hours. An upper level ridge will be over the Gulf of Mexico during the weekend. The upper level winds will be weak and there will be little vertical wind shear. Ida could intensify rapidly once an inner core with an eye and an eyewall develop. Ida could rapidly intensify to a major hurricane over the Gulf of Mexico.

On its anticipated track Ida could approach the coast of Louisiana on Sunday. Ida could be a major hurricane when it nears the coast. Ida will bring strong winds and locally heavy rain to the central Gulf Coast. It could generate a significant storm surge of up to 7 to 11 feet (2 to 3.3 meters). A Storm Surge Watch has been issued for the coast from Sabine Pass to the Alabama/Florida border. The Storm Surge Watch includes Vermilion Bay, Lake Borgne, Lake Pontchartrain, Lake Maurepas, and Mobile Bay.

Tropical Depression Nine Strengthens to Tropical Storm Ida

Former Tropical Depression Nine strengthened to Tropical Storm Ida late on Thursday afternoon. At 5:20 p.m. EDT on Thursday the center of Tropical Storm Ida was located at latitude 18.0°N and longitude 79.8°W which put it about 130 miles (205 km) southeast of Grand Cayman. Ida was moving toward the northwest at 14 m.p.h. (22 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. (65 km/h). The minimum surface pressure was 1006 mb.

Tropical Storm Warnings were in effect for the Cayman Islands. Tropical Storm Warnings were also in effect for the Cuban provinces of Matanzas, Mayabeque, Havana, Artemisa, Pinar del Rio and the Isle of Youth.

A reconnaissance flight into former Tropical Depression Nine by an Air Force Reserve Hurricane Hunter plane on Thursday afternoon found sustained winds to tropical storm force and the National Hurricane Center upgraded the system to Tropical Storm Ida. The circulation around Tropical Storm Ida was gradually becoming more organized. A rainband was wrapping around the eastern and northern sides of the center of Ida. However, the distribution of thunderstorms was still asymmetrical. The strongest thunderstorms were occurring in bands forming on the eastern side of Tropical Storm Ida. An upper level low near Florida was producing south-southwesterly winds that were blowing over the western side of Ida’s circulation. Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Ida will move around the southwestern part of a subtropical high pressure system over the Atlantic Ocean during the next several days. The high will steer Ida toward the northwest. On its anticipated track Tropical Storm Ida will move over the Cayman Islands on Thursday night. Ida could be near western Cuba on Friday evening. Tropical Storm Ida will bring gusty winds and locally heavy rain to the Cayman Islands and parts of western Cuba. Ida will move over the Gulf of Mexico during the weekend. It could approach the central coast of the Gulf of Mexico on Sunday.

Tropical Storm Ida will move into an environment that will become more favorable for intensification during the next 72 hours. The upper low near Florida will move off to the northwest and it will weaken. When the upper low weakens, they vertical wind shear will decrease. Ida will move over water where the Sea Surface Temperatures are near 30°C. Ida could strengthen to a hurricane during the next 36 hours. An upper level ridge will be over the Gulf of Mexico during the weekend. The upper level winds will be weak and there will be little vertical wind shear. Ida could intensify rapidly once an inner core with an eye and an eyewall develop. Ida could rapidly intensify to a major hurricane over the Gulf of Mexico.

On its anticipated track Ida could approach the coast of Louisiana on Sunday. Ida could be a major hurricane when it nears the coast. Ida will bring strong winds and locally heavy rain to the central Gulf Coast. It could generate a significant storm surge.

Tropical Depression Nine Forms over Northwest Caribbean

Tropical Depression Nine formed over the northwestern Caribbean Sea on Thursday morning. At 11:00 a.m. EDT on Thursday the center of Tropical Depression Nine was located at latitude 16.9°N and longitude 79.2°W which put it about 210 miles (340 km) southeast of Grand Cayman. The tropical depression was moving toward the northwest at 13 m.p.h. (20 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 1005 mb.

Tropical Storm Warnings were issued for the Cayman Islands. Tropical Storm Warnings were also issued for the Cuban provinces of Matanzas, Mayabeque, Havana, Artemise, Pinar del Rio and the Isle of Youth.

Satellite images indicated the development of a circulation within a tropical wave over the northwestern Caribbean Sea on Thursday morning and the National Hurricane Center designated the system as Tropical Depression Nine. The circulation around Tropical Depression Nine was still organizing. Bands of showers and thunderstorms were starting to form. The strongest thunderstorms were occurring in bands forming on the eastern side of the tropical depression. An upper level low near Florida was producing south-southwesterly winds that were blowing across the western side of Tropical Depression Nine. Those winds were causing moderate vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.

Tropical Depression Nine will move around the southwestern part of a subtropical high pressure system during the next several days. The high will steer the depression toward the northwest. On its anticipated track Tropical Depression Nine will move over the Cayman Islands on Thursday night. It could be near western Cuba on Friday evening. The system will move over the Gulf of Mexico during the weekend. It could approach the center coast of the Gulf of Mexico on Sunday.

Tropical Depression Nine will move into an environment that will become more favorable for intensification during the next three days. The upper low near Florida will move off to the northwest and it will weaken. When the upper low weakens, they vertical wind shear will decrease. The tropical depression will move over water where the Sea Surface Temperatures are near 30°C. Tropical Depression Nine could strengthen to a tropical storm later today. It could strengthen to a hurricane during the next 36 hours. An upper level ridge will be over the Gulf of Mexico during the weekend. The upper level winds will be weak and there will be little vertical wind shear. A period of rapid intensification could occur when the system moves toward the central Gulf Coast. It could rapidly intensify to a major hurricane.

Tropical Storm Nora Forms South of Acapulco

Tropical Storm Nora formed south of Acapulco, Mexico on Thursday morning. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Nora was located at latitude 12.5°N and longitude 100.8°W which put it about 310 miles (500 km) south of Acapulco, Mexico. Nora was moving toward the west-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 1003 mb.

A Hurricane Watch was issued for the portion of the coast from Lazaro Cardenas to Cabo Corrientes, Mexico. A Tropical Storm Watch was issued for the portion of the coast from Lazaro Cardenas to Tecpan de Galeana, Mexico.

An area of low pressure south of Acapulco, Mexico exhibited more organization on Thursday morning and the National Hurricane Center designated the system as Tropical Storm Nora. The distribution of thunderstorms around Tropical Storm Nora was asymmetrical. The strongest thunderstorms were occurring in bands in the southern half of Nora. Bands in the north half of the tropical storm consisted primarily of showers and lower clouds. Storms near the center of Nora began to generate upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) from the center of circulation.

Tropical Storm will move through an environment somewhat favorable for intensification during the next 36 hours. Nora will move over water where the Sea Surface Temperatures are near 29°C. It will move under the southern part of an upper level ridge centered near Baja California. The ridge will produce northeasterly winds that will blow toward the top of Nora’s circulation. Those winds are already causing the asymmetrical distribution of thunderstorms and they will cause vertical wind shear. The wind shear will inhibit intensification, but it may not be strong enough to keep Tropical Storm Nora from intensifying during the next 36 hours.

Tropical Storm Nora will move around the western end of a high pressure system over Mexico. The high pressure system will steer Nora toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Nora could approach the west coast of Mexico on Friday night. Nora could be a strong tropical storm or a hurricane when it approaches the coast.

Tropical Cyclone Likely to Form over Western Caribbean

A tropical cyclone is likely to form over the western Caribbean Sea during the next few days. At 8:00 a.m. EDT on Wednesday the center of Invest 99L was located at latitude 12.5°N and longitude 75.4°W which put it about 100 miles (160 km) north of Barranquilla, Colombia. Invest 99L was moving toward the west-northwest at 25 m.p.h. (40 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 1006 mb.

A tropical cyclone is likely to form from a tropical wave, currently designated as Invest 99L, that is over the Caribbean Sea north of Colombia. There is currently no low level center of circulation in the tropical wave. Visible satellite images were providing evidence of some rotation in the middle troposphere on Wednesday afternoon. The wave is currently in an environment that is unfavorable for the formation of a tropical cyclone. The wave is over water where the Sea Surface Temperatures are near 29°C. However, an upper level low centered near the Bahamas is producing strong southwesterly winds that are blowing across the western part of the tropical wave. Those winds are causing moderate vertical wind shear and they are inhibiting the development of the wave. Easterly winds in the lower troposphere are pushing lower section of the tropical wave quickly toward the west-northwest, which is also inhibiting development.

The tropical wave will move into an environment more favorable for the development of a tropical cyclone during the next several days. The upper low near the Bahamas is forecast to move toward the northwest and to weaken. When the upper low weakens, the vertical wind shear will decrease around the tropical wave. In addition, the wave is forecast to move more slowly when it reaches the western Caribbean Sea. The National Hurricane Center (NHC) is indicating that there is a 50% probability that a tropical depression will form from the tropical wave in the next 48 hours. NHC is indicating there is a 80% probability that a tropical wave will form during the next five days.

The tropical wave will move around the southwestern part of a subtropical high pressure system over the Atlantic Ocean. The high will steer the tropical wave toward the west-northwest during the next several days. On its anticipated track the tropical wave will approach Nicaragua and Honduras on Thursday. The system could be near the northeastern part of the Yucatan Peninsula on Friday evening. It could move over the Gulf of Mexico during the weekend. The conditions over the Gulf of Mexico could be favorable for intensification during the weekend. The Sea Surface Temperatures in the Gulf of Mexico are near 30°C. An upper level ridge is forecast to be over the Gulf. The upper level winds will be weak in the ridge and there will be little vertical wind shear. If Invest 99L is in the Gulf of Mexico during the weekend, it could strengthen to a hurricane. If it develops into a hurricane with a well formed inner core, then a period of rapid intensification could occur.

Reconnaissance planes are tentatively scheduled to begin to investigate the tropical wave on Thursday afternoon, if necessary. Invest 99L has the potential to pose a serious threat to the northwestern Gulf of Mexico. Interests in Texas, Louisiana, Mississippi, Alabama and Florida should monitor progress of the system.

Marty Weakens to a Tropical Depression

Former Tropical Storm Marty weakened to a tropical depression over the Eastern North Pacific Ocean. At 11:00 a.m. EDT on Tuesday the center of Tropical Depression Marty was located at latitude 20.6°N and longitude 118.1°W which put it about 550 miles (885 km) west-southwest of the southern tip of Baja California. Marty was moving toward the west at 12 m.p.h. (19 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 1006 mb.

Former Tropical Storm Marty weakened to a tropical depression on Tuesday morning when it moved over cooler water. Few, if any, thunderstorms were occurring in the circulation around Tropical Depression Marty. The low level circulation was symmetrical and well organized, but it consisted almost entirely of showers and low clouds.

Tropical Depression Marty will move through an environment unfavorable for intensification during the next several days. Marty will move over water where the Sea Surface Temperatures are near 25°C. The cool water will not supply enough energy to Marty for it to be able to strengthen.

Since the circulation of Tropical Depression Marty exists primarily in the lower levels, it will be steered by the winds near the surface. Marty will move south of the subtropical high pressure system over the Eastern North Pacific Ocean. The high will steer Marty toward the west during the next few days. On its anticipated track Tropical Depression Marty will move farther away from Mexico.

Tropical Storm Marty Develops South of Baja California

Tropical Storm Marty developed over the Eastern North Pacific Ocean south of Baja California on Monday morning. At 5:00 a.m. EDT on Monday the center of Tropical Storm Marty was located at latitude 20.0°N and longitude 111.0°W which put it about 210 miles (340 km) south-southwest of the southern tip of Baja California. Marty was moving toward the west at 15 m.p.h. (24 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 of former Hurricane Grace developed into Tropical Storm Marty south of Baja California on Monday morning. Although the surface circulation of former Hurricane Grace dissipated when it moved across central Mexico during the weekend, the circulation in the middle and upper troposphere remained intact. New thunderstorms began to form when the middle and upper parts of the circulation moved over the Eastern North Pacific west of Mexico. Downdrafts in those thunderstorms transported momentum down to the surface and a low level circulation spun up. More thunderstorms formed near the low level center on Monday morning and the National Hurricane Center designated the system as Tropical Storm Marty.

The circulation around Tropical Storm Marty was well organized. Thunderstorms near the center of Marty were generating upper level divergence that was pumping mass away from the tropical storm. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Marty. Winds to tropical storm force extended out 70 miles (110 km) from the center of Marty.

Tropical Storm Marty will move through an environment somewhat favorable for intensification during the next 24 hours. Marty will move over water where the Sea Surface Temperatures are near 27°C. It will move under the southern part of an upper level ridge centered near Baja California. The ridge will produce easterly winds that will blow toward the top of Marty’s circulation. Those winds will cause vertical wind shear. The wind shear will inhibit intensification, but it will not be strong enough to keep Tropical Storm Marty from getting stronger during the next 24 hours. Marty will move over cooler water on Tuesday and there will be less energy available to the tropical storm.

Tropical Storm Marty will move south of a subtropical high pressure system over the Eastern North Pacific Ocean. The high will steer Marty toward the west during the next several days. On its anticipated track Tropical Storm Marty will move farther away from Baja California.

Elsewhere, the circulation of former Hurricane Linda was approaching Hawaii. At 2:00 a.m. EDT on Monday the center of former Hurricane Linda was located at latitude 21.0°N and longitude 154.8°W which put it about 115 miles (185 km) east of Wailuku,, Hawaii. It was moving toward the west at 12 m.p.h. (19 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 1006 mb. The circulation of former Hurricane Linda will bring gusty winds and locally heavy rain to parts of Hawaii during the next several days.

Tropical Storm Henri Brings Wind and Rain to Northeast U.S.

Tropical Storm Henri brought wind and rain to the northeast U.S. on Sunday. At 2:00 p.m. EDT on Sunday the center of Tropical Storm Henri was located at latitude 41.4°N and longitude 71.8°W which put it about 5 miles (10 km) north of Westerly, Rhode Island. Henri was moving toward the northwest at 9 m.p.h. (15 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 991 mb. Tropical storm force winds extended out 130 miles on the eastern side of Henri. Tropical Storm force winds extended out 80 miles in the western half of the circulation.

A Tropical Storm Warning was in effect for the portion of the coast from East Rockaway Inlet, New York to Chatham, Massachusetts. The Tropical Storm Warning included all of Long Island, Block Island, Martha’s Vineyard and Nantucket.

Former Hurricane Henri weakened back to a tropical storm on Sunday morning when it moved over cooler water north of the Gulf Stream. Even though it was weaker, Tropical Storm Henri was producing gusty winds along the coast. A weather station on Block Island, Rhode Island reported a sustained wind speed of 52 m.p.h. (84 km/h) and a wind gust to 65 m.p.h. (105 km/h). A weather station at Point Judith, Rhode Island reported a sustained wind speed of 51 m.p.h. (82 km/h) and a wind gust to 69 m.p.h. (111 km/h). A NOAA C-MAN station at Buzzards Bay, Massachusetts reported a sustained wind speed of 49 m.p.h. (79 km/h) and a wind gust to 57 m.p.h. (92 km/h). The gusty winds were causing scattered power outages in southern New England.

Tropical Storm Henri was also dropping heavy rain over parts of the northeastern U.S. Flash Flood Watches were in effect for northeastern Pennsylvania, southeastern New York and southern New England.

Tropical Storm Henri will move slowly toward the northwest during the rest of Sunday. The westerly winds in the middle latitudes will begin to steer Henri toward the east-northeast on Monday. Tropical Storm Henri will continue to weaken as it moves inland over southern New England. Henri will continue to drop heavy rain on some locations and the risk of flash floods will continue into early next week.

Hurricane Henri Moves Toward Long Island

Hurricane Henri moved toward Long Island on Saturday night. At 11:00 p.m. EDT on Saturday the center of Hurricane Henri was located at latitude 38.6°N and longitude 71.0°W which put it about 180 miles (290 km) south-southeast of Montauk Point, New York. Henri was moving toward the north at 11 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 987 mb.

A Hurricane Warning was in effect for eastern Long Island from Fire Island Inlet to Port Jefferson Harbor. A Hurricane Warning was also in effect for the portion of the coast from New Haven, Connecticut to Westport, Massachusetts. The Hurricane Warning included Block Island. A Tropical Storm Warning was in effect for the south coast of Long Island from East Rockaway Inlet to Fire Island Inlet. A Tropical Storm Warning was in effect for the north coast of Long Island from East Rockaway Inlet to Port Jefferson, Harbor. A Tropical Storm Warning was in effect for the portion of the coast from East Rockaway Inlet to New Haven, Connecticut. A Tropical Storm Warning was in effect from the portion of the coast from Westport, Massachusetts to Chatham, Massachusetts. The Tropical Storm Warning included Nantucket and Martha’s Vineyard. A Tropical Storm Warning was also in effect for the portion of the coast from East Rockaway Inlet, New York to Manasquan Inlet, New Jersey. The Tropical Storm Warning included New York City.

Hurricane Henri exhibited more organization on Saturday night but reconnaissance flights were not finding an increase in the wind speeds. A circular eye with a diameter of 30 miles (50 km) formed at the center of Henri. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring. Bands of showers and thunderstorms were revolving around the core of Henri. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease slowly on Saturday. Winds to hurricane force extended out 35 miles in the southeastern quadrant of Henri. The winds in the other parts of Henri were blowing at less than hurricane force. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Hurricane Henri will move through an environment favorable for intensification during the next few hours. Henri will move over the Gulf Stream where the Sea Surface Temperatures are near 29°C. It will move around the eastern side of an upper level trough over the eastern U.S. The trough will produce southerly winds that will blow toward the top of Henri’s circulation. Those winds will cause some vertical wind shear, but the shear may not be enough to prevent some intensification during the next few hours. Hurricane Henri could strengthen during the next 6 hours. Henri will move over cooler water when it moves north of the Gulf Stream on Sunday and that will cause it to weaken. Some drier air could wrap around the western and southern sides of Hurricane Henri on Sunday.

The upper level trough will steer Hurricane Henri toward the north-northwest on Sunday. On its anticipated track Hurricane Henri will approach Long Island during the middle of the day on Sunday. Henri could still be a hurricane when it nears Long Island. Hurricane Henri is likely to cause minor wind damage on Long Island and in southern New England. Gusty winds and falling trees could cause widespread power outages. Henri could move more slowly when it moves across southern New England. Locally heavy rain over a prolonged period could cause flash floods. Hurricane Henri could cause a storm surge of up to 4 to 7 feet (1 to 2 meters) where the wind blows the water toward the coast.