As of Wednesday afternoon, Isaias had maximum sustained winds of 65 miles per hour and was located about 500 miles south-southwest of the mouth of the Mississippi River, moving east-northeast at 8 miles per hour. The storm's central pressure had fallen about 10 millibars since the morning, indicating strengthening.
NHC Director Michael Brennan said Isaias is expected to move northeastward to east-northeastward through Thursday while rapidly strengthening into a hurricane. It is forecast to turn north-northeastward on Friday and reach at or near major hurricane strength before coming ashore Friday night or early Saturday as a strong hurricane.
A hurricane watch extends from Bay St. Louis, Mississippi, to Indian Pass, Florida, including Mobile, Pensacola and Panama City. The watch also extends inland into parts of the Florida Panhandle and south-central Alabama. Tropical storm watches cover additional areas inland and on either side. Tropical storm conditions could begin along the affected coast Friday afternoon or evening, followed by hurricane conditions as the center comes ashore.
A storm surge watch stretches from the mouth of the Mississippi River to Yankeetown, Florida, covering the Mississippi and Alabama coasts, the Florida Panhandle and the Big Bend region. Water could rise 5 to 7 feet above ground level along portions of the Mississippi, Alabama and Florida coasts, including Mobile Bay, especially near and to the right of where the center makes landfall.
“The size of Isaias is expected to be quite large,” Brennan said, warning that dangerous storm surge could extend hundreds of miles east of the landfall location.
Rainfall could reach 10 inches near where the storm’s core comes ashore. A level three out of four risk for flash flooding is forecast from Friday into Saturday across an area including Mobile, Pensacola, Panama City and parts of south-central Georgia.
Isaias is expected to weaken into a tropical storm and then a tropical depression as it moves through the southeastern United States. Its moisture could bring scattered flash flooding across much of the region through the weekend. “You’ve got tonight and all day Thursday to get ready for the storm,” Brennan said.