While predictions show Hurricane Florence heading for North Carolina, the amount of rainfall it could send Charleston's way carries a potential for flooding.
The Charleston area currently is expected to see at least 1-2 inches of rain over the next several days. But it's possible the eye of Hurricane Florence will take a slight right turn to the south on Friday as it makes its way over eastern North Carolina, which could send a lot more rain to the Charleston area, according to Neil Dixon of the National Weather Service in Charleston.
"Any southward adjustment at all is going to have significant impacts on our rainfall," he said. "Just seeing the potential for the storm to slow and meander around is very concerning. Right now, it looks like that could occur north of us, but it wouldn’t be unreasonable to expect a greater rainfall impact for our region."
Florence is expected to cause higher tides along South Carolina's coast, too, which is a flooding threat on its own for Charleston's lowest-lying areas. If a band of heavy rain shows up at the same time, that worsens the problem.
This map, created by the National Oceanic and Atmospheric Administration, shows how much the coastline would be inundated by storm surge from a Category 1 hurricane.
Bottom line, he said, Charleston residents should prepare for flooding, regardless of what the culprit might be.
There aren't any resources for people to gauge how much their properties might flood if a heavy rain coincides with tidal flooding. The Federal Emergency Management Agency's flood maps for the Charleston area only account for tidal flooding, so properties that often flood during a heavy rain often aren't considered to be in a high-risk flood zone.
That's one reason more than a third of flood insurance claims are made outside of those zones, according to Lisa Sharrard, an insurance agent and owner of U.S. Flood Solutions in Columbia.
Everyone should prepare for a storm as if they're in a high-risk area, she said, especially when there's a potential for heavy rain and storm surge at the same time.
She cautioned against assuming a property won't flood based on what happened during a previous storm, such as Tropical Storm Irma.
"This is a different storm because the prediction is, it’s going to move slower," she said. "The slower that storm moves, the more flooding it will cause because of more rainfall."
This map, created by the National Oceanic and Atmospheric Administration, shows the areas susceptible to tidal flooding.
While low tides help drain out excess water, it can take a few tide cycles for some parts of the Charleston area to recover from a major flood.
And Charleston also has seen how much rainfall flooding is possible even at low tide. In late July, slow-moving thunderstorms dropped up to 8 inches of rain, shutting down large swaths of downtown Charleston, totaling dozens of cars and flooding homes.
Storm water systems — even updated ones — often aren't equipped to deal with those relatively extreme weather events.
The problem is those extreme weather events are becoming more common.