The former Tropical Storm Karen, since downgraded to a depression, hovered early Sunday near Louisiana's extreme southeast coastline and threatened to lash vulnerable low-lying areas with heavy rain.
But all tropical storm warnings were discontinued earlier in the weekend after the system had been downgraded from a weak tropical storm while lumbering off the Gulf Coast.
The National Hurricane Center in Miami said late Saturday that the storm was expected to move near or over parts of extreme southeastern Louisiana on Sunday and then run just south of the central Gulf Coast from Alabama to the Florida Panhandle in coming hours.
Forecasters and emergency officials warned residents to keep an eye on developments in case things changed.
Ahead of the storm, squalls of rain hit workers sandbagging low sections of the flood-prone town of Lafitte, La., along Bayou Barataria.
Lafitte resident April Terrebonne decided to stay at her house, but took precautions.
"We've been preparing for the water, if it does come up. We've moved everything, and we're just getting prepared," she said.
The storm system had maximum sustained winds of 35 mph (55 kph) after being downgraded earlier in the weekend from a tropical storm. It was about 185 miles (295 kms) west-southwest of the mouth of the Mississippi River late Saturday.
The National Weather Service said storm surges and localized flooding were possible along parts of the northern Gulf Coast. It added rainfall accumulations of up to 3 inches were possible on the central Gulf Coast and in some Southeastern states through Monday evening near or in the storm's path.
In low-lying Plaquemines Parish, La., officials changed an evacuation order from mandatory to voluntary Saturday afternoon. More than 80 evacuees from the area, at the state's southeastern tip, had taken refuge at a public shelter, which would remain open Saturday.
They gathered in an auditorium where they rested on cots, watched for weather updates on TV and chatted outside on the front steps.
"I don't really know what to expect, but they told us to evacuate, so we got out," said Dana Etienne, 27, of Phoenix, La., who was at the shelter with her three young children.
Coastal authorities closed flood gates along waterways that could be affected by tides driven by the storm. In New Orleans, the U.S. Army Corps of Engineers continued closing barriers designed to keep surge out of the Inner Harbor Navigation Canal — scene of catastrophic flooding in 2005 when flood walls failed during Hurricane Katrina.
Col. Richard Hansen of the corps said more gates along various canals could be closed, and warned boaters not to get caught on the wrong side of those gates "If there is a gate in the system, it may not be open when you decide to come back in," Hansen said.
At the Port of New Orleans, port officials working with the Coast Guard said they were optimistic that vessel traffic at the mouth of the Mississippi River, halted since Friday morning, would resume Sunday. The port remained busy, officials said in a news release, with some of the nine ships at dock there still working cargo. Two Carnival cruise ships that had to delay weekend arrivals were expected Monday.
Dan Hahn, emergency operations planner for Santa Rosa County in the Florida Panhandle said Karen appeared to be a "nonevent" for the region.
The county had activated its Emergency Operations Center for the weekend, but decided to close it after getting the latest update on the storm's path. Hahn said he and other officials were relieved the storm wasn't more developed. But Hahn still urged residents to pay attention to weather updates and to be prepared for any emergency.
"Complacency is always a concern, but we aren't seeing that," he said, adding that most Panhandle residents take tropical weather seriously because of the large storms that have struck the region in the past.
Mississippi Emergency Management Agency spokesman Brett Carr said the Mississippi National Guard was demobilized Saturday and emergency operations were being scaled back.