Idalia, now a tropical storm, touched down in Florida as a Category 3 hurricane.
Idalia touched down in Florida's Big Bend region on Wednesday morning as a powerful Category 3 hurricane -- the strongest hurricane to ever make landfall in the Apalachee Bay.
Idalia has since weakened into a tropical storm and moved inland over Georgia and the Carolinas.
The tide in Charleston, South Carolina, is believed to be the fifth-highest peak tide on record, according to the National Weather Service (NWS).
The tide level at Charleston Harbor peaked at 3.47 feet "mean higher high water," or 9.23 feet "mean lower low water," Wednesday evening, according to NWS.
-ABC News' Kenton Gewecke
The National Weather Service issued a tornado watch until 4 a.m., local time, for parts of North Carolina as Tropical Storm Idalia makes its way through the area.
Many people will be able to observe and take photos of Wednesday night's rare blue supermoon, but those impacted by Hurricane Idalia may experience worse tidal flooding because of the supermoon.
A blue moon refers to the second time a full moon appears during the same month. A supermoon is when it is at the closest point in its orbit around the Earth, according to NASA.
Both high and low tides are more intense with a supermoon because of the moon's gravitational pull on the oceans, according to NASA.
"Perigean high tides during a full moon and new moon can cause major problems on some coasts, especially if weather adds high waves or a storm surge," NASA said.
Areas in Pasco County, Florida to St. Petersburg, Florida, experienced flooding after Idalia made landfall on Wednesday as a Category 3 hurricane.
ABC News Chief Meteorologist Ginger Zee predicted flooding may occur in Savannah, Georgia, and in Charleston, South Carolina, as Idalia, now a tropical storm, makes its way through the region.
The National Weather Service (NWS) in Charleston, South Carolina, said water has breached the Charleston Battery and dunes at Edisto Beach -- flowing onto roadways and into downtown Charleston.
High tide is coming shortly as well, which will compound the impacts. The NWS said the tide is "already in the top 8 of peak tides on record" -- and rising.
-ABC News' Kenton Gewecke
