A few fishing camps and small hamlets along the coast were ordered evacuated late Wednesday, and some boat services were suspended for the estimated 35,000 tourists currently in Cancun. But the head of the Cancun Hotel Association, Roberto Cintron, said tourists appeared to be taking it in stride.
While meteorologists said it was too soon to predict the storm's ultimate intensity, they said it could weaken a bit as it approaches the coast over the weekend.
"Our forecast calls for it to be right around the border of a hurricane and a tropical storm," said David Zelinsky, a hurricane center meteorologist.
Whether it's a weak hurricane or strong tropical storm, Karen's effects were expected to be largely the same: Heavy rain with the potential for similar storm surge.
Forecasters say Karen is expected to bring 4 to 8 inches of rain to portions of the central and eastern Gulf Coast through Sunday night, mainly near and to the right of the path of the center.
Camardelle, whose vulnerable island is often the first to order an evacuation in the face of a tropical weather system, said the town was making sure its 10 pump stations are ready. He encouraged residents to clean out drainage culverts and ditches in anticipation of possible heavy rain and high tides.
"Hopefully, this one is just a little rain event," Camardelle said. "We don't need a big storm coming at us this late in the season."
Forecasters said a cold front approaching from the northwest was expected to turn Karen to the northeast, away from the Louisiana coast and more toward the Florida Panhandle or coastal Alabama. But the timing of the front's arrival over the weekend was uncertain.
Grand Isle suffered damage from Hurricane Isaac in August 2012. Isaac clipped the mouth of the Mississippi River for its official first landfall before meandering northwest over Grand Isle and stalling inland. Though a weak hurricane, Isaac's stall built a surge along the southeast Louisiana coast that flooded communities in neighboring Plaquemines Parish.
Karen was expected to pass over Gulf oil and gas fields from Louisiana to Alabama, but early forecasts suggested the storm would miss the massive oil import facility at Port Fourchon, La., just west of Grand Isle, and the oil refineries that line the Mississippi River south of Baton Rouge.
Associated Press writers Mark Stevenson in Mexico, Emily Wagster Pettus in Jackson, Miss., and Michael J. Mishak in Miami contributed to this report.