Former Tropical Storm Henri strengthened to a hurricane on Saturday morning. At 11:00 a.m. EDT on Saturday the center of Hurricane Henri was located at latitude 34.4°N and longitude 72.5°W which put it about 180 miles (290 km) east-southeast of Cape Hatteras, North Carolina. Henri was moving toward the north-northeast 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 991 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.
Reconnaissance planes found that former Tropical Storm Henri has strengthened to a hurricane on Saturday morning. More thunderstorms formed near the center of Henri and the inner end of a rainband wrapped around the north side of the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the hurricane. The removal of mass caused the surface pressure to decrease. Winds to hurricane force extended out 60 miles in the southeastern quadrant of Henri. The winds in the other parts of the storm were blowing at less than hurricane force. Winds to tropical storm for extended out 130 miles (210 km) from the center of circulation.
Hurricane Henri will move through an environment favorable for intensification during the next 18 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 southwesterly winds that will blow toward the top of Henri’s circulation. Those winds will cause some vertical wind shear, but the shear will not be enough to prevent intensification. Hurricane Henri is likely to strengthen during the next 12 hours. Henri will move over cooler water when it moves north of the Gulf Stream on Sunday and that will cause it to weaken.
The upper level trough will steer Hurricane Henri toward the north-northeast during the next 12 hours. The position and orientation of the trough will change as it interacts with Hurricane Henri. The trough will pull Henri toward the north-northwest on Sunday. On its anticipated track Hurricane Henri will approach Long Island on Sunday afternoon. Henri could 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 slowly when it moves across southern New England. Locally heavy rain 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.
Elsewhere, Tropical Storm Grace was dropping heavy rain over parts of central Mexico. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Grace was located at latitude 19.7°N and longitude 98.9°W which put it about 25 miles (40 km) north-northeast of Mexico City, Mexico. Grace was moving toward the west-southwest at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 990 mb.
A Tropical Storm Warning was in effect for the portion of the coast from Puerto Veracruz to Barra de Tordo, Mexico.