Update Wednesday at noon:
Isaac remained a tropical storm Wednesday as it neared the Lesser Antilles, where it was expected to land on Thursday.
Tropical storm warnings were in effect for Martinique, Dominica and Guadeloupe, while watches were in effect for Montserrat, St. Kitts and Nevis, Antigua, and Saba and St. Eustatius.
“Life-threatening flash flooding is possible with Isaac. The storm is expected to produce total rainfall accumulations of 2 to 4 inches with isolated amounts up [to] 8 inches across Martinique, Dominica and Guadeloupe,” the U.S. National Hurricane Center advised Wednesday morning.
Rainfall of 1 to 2 inches was expected to affect Puerto Rico and the United States Virgin Islands with isolated areas receiving up to 4 inches.
The storm is not currently forecast to hit the Cayman Islands, but residents should continue to monitor its progress.
Isaac was moving west near 17 mph. Aircraft data indicated maximum sustained winds near 60 miles per hour with higher gusts, according to the NHC.
Gradual weakening is forecast during the next 72 hours.
Surf swells from Isaac could be life-threatening and coastal flooding is a risk in the Lesser Antilles.
The southeastern Caribbean went on alert Tuesday, as the first hurricane and tropical storm watches were issued for Isaac.
The storm, initially expected to hit the Lesser Antilles Thursday as a Category 1 hurricane, has been downgraded to a tropical storm. That does not mean residents should rest easy, however, according to the U.S. National Hurricane Center.
“Isaac is expected to be at or near hurricane intensity when it approaches the Lesser Antilles on Thursday, and hurricane and tropical storm watches have been issued for several islands. Interests in those areas should follow any advice given by their local officials,” the National Hurricane Center said Tuesday morning.
Isaac is not currently forecast to impact the Cayman Islands, but residents should observe the progress of the storm, currently positioned east of the southern Caribbean in Atlantic waters.
The tropical storm was moving west near 16 mph as of Tuesday afternoon.
A hurricane watch is in effect for Guadeloupe, Martinique and Dominica, while a tropical storm watch is in effect for Antigua, Montserrat, and St. Kitts and Nevis.
Rainfall of 3 to 5 inches with isolated amounts nearing 10 inches is forecast for the Leeward Islands later this week. A storm surge of 2 to 4 feet above normal levels is also anticipated.
“Swells generated by Isaac will begin to affect portions of the Lesser Antilles on Wednesday afternoon. These swells are likely to cause life-threatening surf and rip current conditions,” the National Hurricane Center said.
Meanwhile, sunny weather returned to Cayman on Tuesday, as a tropical wave moved away from the islands and toward the U.S. Gulf Coast.
“Cloudiness and showers associated with the interaction between a tropical wave and an upper level trough will continue to decrease across the Cayman area … as the tropical wave moves west over the Yucatan Peninsula. Radar images show isolated showers in and around the Cayman area moving towards the northwest,” the Cayman Islands National Weather Service said Tuesday.
That tropical wave is forecast by the U.S. National Hurricane Center at a 70 percent chance of cyclone formation within the next five days. Gulf residents, particularly in northeastern Mexico, Texas and Louisiana, should monitor the progress of the storm.
Two active hurricanes – Florence and Helene – were also moving across the Atlantic Tuesday. While Helene is expected to stay in Atlantic waters, Florence posed a serious threat to the U.S. East Coast. The storm is forecast to make landfall near the Carolinas Thursday or Friday as a major hurricane with winds around 130 mph.
North Carolina Gov. Roy Cooper called the storm a “monster.” “It’s big and it’s vicious. It is an extremely, dangerous, life-threatening, historic hurricane,” he told the Associated Press.
“The waves and the wind this storm may bring is nothing like you’ve ever seen. Even if you’ve ridden out storms before, this one is different. Don’t bet your life on riding out a monster.” Mass evacuations were ordered across North and South Carolina and Virginia, and states of emergency were issued by the federal government.