Tropical weather heated up across the Atlantic Wednesday, prompting alerts throughout the region, from the U.S. East Coast to the Caribbean’s Lower Antilles, as two active hurricanes, two named storms and two potential storms brewed.
Mandatory evacuation orders were in effect for much of North Carolina, South Carolina and Virginia as Category 3 Hurricane Florence bore down on the states. In South Carolina, local officials reported 300,000 had already evacuated the coast as of Wednesday.
The most immediate threat to the Caribbean, Isaac, remained a tropical storm Wednesday as it neared the Lesser Antilles, where it was expected to arrive 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.
As of Wednesday afternoon, the storm was not forecast to hit the Cayman Islands, but residents should continue to monitor its progress.
“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.
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.
Isaac was moving west Wednesday afternoon at a speed of almost 17 mph. Aircraft data indicated maximum sustained winds near 60 miles per hour with higher gusts, according to the National Hurricane Center.
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.
Of the Atlantic’s two active hurricanes – Florence and Helene – Florence posed the greatest threat to land, as it neared the Carolinas and Virginia as a Category 3 hurricane.
Although Florence was downgraded from Category 4 status, it is still considered an extremely dangerous storm with maximum sustained winds near 125 mph.
“A life-threatening storm surge is highly likely along portions of the coastline of South Carolina and North Carolina, and a Storm Surge Warning is in effect for a portion of this area,” the National Hurricane Center said Wednesday.
“Life-threatening, catastrophic flash flooding and significant river flooding is likely over portions of the Carolinas late this week into early next week, as Florence is expected to slow down as it approaches the coast and moves inland.”
In addition to hurricane-force winds, Florence was forecast to produce large swells and life-threatening rip currents from the U.S. East Coast to Bermuda.
In contrast, no coastal watches or warnings were in effect for Helene, but residents of the Azores were encouraged to monitor the storm. As of Wednesday afternoon, Helene had maximum sustained winds near 90 mph.
Another system in north-central Atlantic waters was upgraded to a subtropical storm, Joyce, Wednesday afternoon as it approached the Azores.
There were two other systems in development Wednesday as well. One system, moving toward Texas in the Gulf Coast, was forecast at a 70 percent chance of cyclone formation over the next 48 hours. Another system began forming near Hurricane Florence and was forecast at a 20 percent chance of formation over five days.