NEW ORLEANS — Though weakening slightly, Tropical Storm Karen remained poised Friday to become the first named storm to hit the U.S. in what has been a relatively quiet hurricane season.
National Hurricane Center forecasters expect Karen to be near the central Gulf Coast on Saturday, likely as a weak hurricane or tropical storm. From a tiny, vulnerable island off the Louisiana coast to the beaches of the Florida Panhandle, Gulf Coast residents prepared Friday for a possible hit from the storm.
A hurricane watch was in effect for Grand Isle, La., to west of Destin, Fla. A tropical storm warning is in effect for Morgan City, La., to the mouth of the Pearl River.
The center said late Friday morning that Karen was about 250 miles (405 kilometers) south-southwest of the mouth of the Mississippi River and 290 miles (465 kilometers) south-southeast of Morgan City, La. It's moving north-northwest at 10 mph (17 kph). Maximum sustained winds were 50 mph (85 kph).
Karen is expected to produce rainfall of 3 to 6 inches through Sunday night, with isolated totals up to 10 inches possible.
In Alabama, safety workers Thursday hoisted double red flags at Gulf Shores because of treacherous rip currents. Lifeguard stands were moved off the beach to higher ground. Still, no evacuations were planned. The Bayfest music festival was set to begin Friday, and organizers said the show — with a lineup including the Zac Brown Band and R.Kelly — would go on as much as possible.
In Mississippi, Gov. Phil Bryant declared a state of emergency, urging residents to prepare. State Emergency Management Agency Director Robert Latham said local schools will decide whether to play football games. He said the southern part of the state could have tropical storm-force winds by late Friday.
"I know that Friday night football in the South is a big thing, but I don't think anybody wants to risk a life because of the potential winds," Latham said.
Louisiana Gov. Bobby Jindal also declared a state of emergency, citing the possibility of high winds, heavy rain and tides. Florida Gov. Rick Scott declared an emergency for 18 counties.
Traffic at the mouth of the Mississippi River was stopped Friday morning in advance of the storm.
The Army Corps of Engineers said it was closing a structure intended to keep storm surge out of the Inner Harbor Navigation Canal in Louisiana — known locally as the Industrial Canal — where levee breaches during Hurricane Katrina led to catastrophic flooding in 2005.
Mayor David Camardelle of Grand Isle, La., an inhabited barrier island and tourist town about 60 miles south of New Orleans, called for voluntary evacuations as he declared an emergency Thursday afternoon.
Louisiana officials were taking precautions while noting that forecasts show the storm veering to the east. The storm track had it likely brushing the southeastern tip of the state before heading toward the Alabama-Florida coast. And it was moving faster than last year's Hurricane Isaac, a weak storm that stalled over the area and caused widespread flooding.
"It should make that fork right and move out very, very quickly," said Jerry Sneed, head of New Orleans' emergency preparedness office.
Offshore, at least two oil companies said they were evacuating non-essential personnel and securing rigs and platforms.
In Washington, the White House said the Federal Emergency Management Agency was recalling some workers furloughed due to the government shutdown to prepare for the storm.
White House spokesman Jay Carney said President Barack Obama was being updated about the storm. He said Obama directed his team to ensure staffing and resources are available to respond to the storm.
Hundreds of thousands of federal workers have been furloughed under the partial government shutdown. It's unclear how many FEMA workers are being brought back.
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.
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.