Some people in Morgan City, La., have decided to ride out the storm, but others are evacuating because of memories of Hurricane Katrina.
Morgan City is about 90 miles west of New Orleans.
The town could see storm surge damage since it is surrounded by swamps.
On Monday, stores like Walmart and Target were crowded with shoppers stocking up on supplies, including bread and water.
"It's pretty scary going through what we went through with Rita and everything. So we want to be prepared, make sure we have food and water," said Cheryl Fontenot who was buying storm supplies.
Several businesses boarded up their windows and gas was difficult to find in the town.
However, there were some locals who decided they were not going to leave, no matter how powerful Isaac could become.
"I think it's more of flooding and people aren't sure of what's going to happen with their roofs, just minor things," said Gavin Blankenship, a resident in Morgan City.