The moon will be closest to Earth on Wednesday (August 30), making its gravitational pull on the planet stronger. That means the spectacular phenomenon could raise the tides higher than usual and make Idalia's hazards more dangerous.
"I would say the timing is pretty bad for this one," Brian Haines, the meteorologist leading the National Weather Service office in Charleston, South Carolina, told the Associated Press.
Storm surges are usually the most deadly aspects of a hurricane. Huge walls of water pour onto land, damaging structures and sweeping people into precarious situations. The National Hurricane Center expects parts of Florida's Gulf Coast to see between 7 to 15 feet of water, according to Tuesday (August 29) projections.
Weather experts also warn the surprising team-up could intensify tidal flooding in Georgia and South Carolina, as well. Haines predicts Idalia could swing close to Charleston and the surrounding Lowcountry, drowning parts of the downtown area. NWS forecasts an 8.2-foot tide in Charleston by Wednesday evening.
"Wednesday evening looks really nasty for coastal flooding here," he said.