If a remnant of Hurricane Isaac becomes a tropical system in the Gulf of Mexico -- which forecasters say could happen -- it would be a rare event.
In 2005, a remnant from a tropical depression that dissipated near Puerto Rico eventually became part of a new depression, which evolved into Hurricane Katrina.
National Hurricane Center forecaster Todd Kimberlain says Katrina was the only modern example he could find of a system's partial remains regenerating and getting a different tropical designation.
If the Gulf system becomes a tropical storm, it probably would be named Nadine. At midday Thursday, forecasters gave it a 40 percent chance of developing. An approaching cold front could influence its future.
The Gulf Coast is cleaning up after Isaac made landfall the night of August 28th-29th.