Reaching wind speeds of 75 mph, the storm Isaac is now a Category 1 hurricane and is moving northwest toward the mouth of the Mississippi River. It's expected to make landfall along the Louisiana coast tonight.
Florida, Mississippi and Louisiana are under hurricane advisory warnings as many communities along those states' coasts are being evacuated.
"We fully expect that we will get the brunt of it," New Orleans Mayor Mitch Landrieu said at a briefing Tuesday afternoon, NBC News writes.. "We think that we're well prepared," he added, while saying that much depends on how well residents heed warnings to hunker down.
The National Hurricane Center expects heavy flooding due to Isaac. The Center predicts Isaac to make landfall in southeastern Louisiana as early as this evening.
Cities in Florida have shut down the coast line from Pensacola to Panama City, according to local news reports. Areas near central and western Palm Beach County got walloped with more than 14 inches of rain from the storm recently, the Sun Sentinel writes.
USA Today reports engineers closed the floodgates around New Orleans in order to keep water from the Gulf from surging into the area "as Isaac moves closer to shore, threatening to cause major flooding."
This visible image of Tropical Storm Isaac taken from NOAA's GOES-13 satellite shows the huge extent of the storm, where the eastern-most clouds lie over the Carolinas and the western-most clouds are brushing east Texas.
As far as storms go, Isaac is quite wide, NBC News writes, Tropical storm-force winds stretch 185 miles from its center and hurricane-force winds extend out 60 miles.
Compared to Katrina, Isaac isn't as powerful (but still shouldn't be underestimated). Katrina, striking Louisiana in August 2005, at one point reached Category 5 status with winds of more than 157 mph, and made landfall as a Category 3 storm.
A Google Map lists the areas currently under hurricane warnings and evacuation orders.