Grand Isle, Louisiana is under a mandatory evacuation.  All visitors must leave the island immediately.  Residents have until 9am tomorrow (Monday) to leave.  Here is the statement from Grand Isle officials:

MAYOR DAVID CAMARDELLE HAS DECLARED A STATE OF EMERGENCY AS OF 2:00 P.M., SUNDAY, AUGUST 26, 2012 DUE TO APPROACHING TROPICAL STORM ISAAC IN THE GULF OF MEXICO. DUE TO TROPICAL STORMS WATCH BEING ISSUED FOR THE ENTIRE EASTERN GULFCOAST  BY THE NATIONAL WEATHER SERVICE, A MANDATORY EVACUATION IS  IN EFFECT FOR CAMPER TRAILERS, RECREATIONAL VEHICLES AND TOURIST AT 2:00 P.M. TODAY. A MANDATORY EVACUATION FOR RESIDENTS AS OF 9:00 A.M., MONDAY, AUGUST 27, 2012. LISTEN TO NEWS SERVICES BROADCAST FOR INFORMATION.