A potential threat from Tropical Storm Henri prompted the issuance of Hurricane Watches for parts of Long Island and southeastern New England on Friday morning. At 8:00 a.m. EDT on Friday the center of Tropical Storm Henri was located at latitude 30.0°N and longitude 73.7°W which put it about 375 miles (600 km) southeast of Cape Hatteras, North Carolina. Henri was moving toward the west-northwest at 9 m.p.h. (15 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 995 mb.

A Hurricane Watch was issued for eastern Long Island from Fire Island Inlet to Port Jefferson Harbor. A Hurricane Watch was also issued for the portion of the coast from New Haven, Connecticut to Sagamore Beach, Massachusetts. The Hurricane Watch included Block Island, Martha’s Vineyard and Nantucket. A Tropical Storm Watch was issued for the south coast of Long Island from East Rockaway Inlet to Fire Island Inlet. A Tropical Storm Watch was issued for the north coast of Long Island from East Rockaway Inlet to Port Jefferson Harbor. A Tropical Storm Watch was also issued for the portion of the coast from East Rockaway Inlet to New Haven, Connecticut.

Tropical Storm Henri did not change much during Thursday night. The distribution of thunderstorms around Henri remained asymmetrical. The strongest thunderstorms were occurring in bands in the southern half of Henri. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Henri was moving under the southeastern part of an upper level ridge off the east coast of the U.S. The ridge was producing northeasterly winds that were blowing toward the top of Henri’s circulation. Those winds were causing moderate vertical wind shear and they were also contributing to the asymmetrical distribution of thunderstorms. Winds to tropical storm force extended out 90 miles (145 km) from the center of Henri.

Although Tropical Storm Henri is currently moving toward the west-northwest, an upper level trough over the eastern U.S. will turn Henri toward the north on Friday. The trough will steer Henri toward the north on Saturday. When Henri turns toward the north it will move under the axis of the upper level ridge. The upper level winds are weaker near the axis of the ridge and the wind shear will be less. Tropical Storm Henri is likely to strengthen to a hurricane on Saturday. Henri will move over the warm water in the Gulf Stream and there is a chance that Henri could strengthen to Category 2 on the Saffir-Simpson Scale.

A high pressure system will move northeast of Henri on Sunday. The high pressure system will block Henri and prevent it from moving toward the northeast. The high pressure system will also slow the forward speed of Henri. Henri could be moving slowly when it nears Long Island and southeastern New England. A slow forward speed would increase the time period when places experience strong gusty winds, which would increase the chance for wind damage and power outages. Slow movement would also increase the total rainfall in many locations and the risk for flash floods would increase. Henri could also cause a storm surge of up to 4 to 7 feet (1 to 2 meters) along the coast.

Elsewhere, former Tropical Storm Grace strengthened back to a hurricane over the southwestern Gulf of Mexico on Friday morning. At 8:00 a.m. EDT on Friday the center of Hurricane Grace was located at latitude 20.6°N and longitude 93.7°W which put it about 185 miles (300 km) east-northeast of Veracruz, Mexico. Grace was moving toward the west at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 983 mb.

A Hurricane Warning was in effect for the portion of the coast from Puerto Veracuz to Cabo Rojo, Mexico. A Tropical Storm Warning was in effect for the portion of the coast from Cabo Rojo to Barra del Tordo, Mexico.