The Coast Guard says that given "hurricanes and tropical storms can be deadly' its ability to do rescues "can be diminished or non-existent at the height of the storm", so it advises people to "be prepared, stay informed, and heed storm warnings".
The danger to New Orleans - bound by the Mississippi River on its south side, Lake Pontchartrain on its north side and tributaries leading into the nearby Gulf of Mexico on the east - is threefold: storm surges from the sea, rain from the sky and water from the rising river if the levees fail.
An informational meeting was held Friday in Mobile to provide public officials details about the return of passenger rail to the Gulf Coast. There is a "mega shelter" in place in Alexandria, a city centrally-located in the state. This threat includes New Orleans. Main threat Saturday afternoon and evening is locally heavy rain, gusty winds up to 40 m.p.h, and frequent lightning.
As of Friday morning, Barry was about 95 miles southwest of the mouth of the MS, with winds around 50 mph, well short of the 74 mph hurricane threshold.
Mississippi Gov. Phil Bryant signed an emergency declaration while President Donald Trump declared a federal emergency for Louisiana, authorizing the Department of Homeland Security and the Federal Emergency Management Agency to coordinate relief efforts.
By the time it makes landfall Saturday, it is expected to reach hurricane status - winds of at least 74 miles per hour. At the time, the storm was about 100 miles southwest of the mouth of the Mississippi River; forecasters say Barry could become a Category 1 hurricane before it makes landfall. The forecast is for 3 to 6 feet of water over normally dry land in low-lying coastal areas. "It's always been about the rain".
"It's deeper than they believe it to be, and also there's current that sometimes is imperceptible", Edwards said. He lived through Hurricane Katrina, and like so many residents, isn't taking any chances again.
"Water, we have a bunch of nuts and things", he says.
"When Katrina came through here, some people stayed".
Still, the unusual confluence of factors is rattling nerves along the "sliver by the river", a swath of relatively high ground along the MS that's less likely to flood in typical rain and hurricane storm surge events than other areas. But many residents aren't too eager to leave.
Power outages were moderate Friday evening with about 15,000 customers (including businesses) without electricity, according to the website PowerOutage.us.
"Everything I own is in it", he said of his truck.
Across the coast, many cities and parishes have issued mandatory evacuation orders, the governor said.
With New Orleans already recovering from flooding earlier in the week, the situation is about to get much worse. This could be a major test for the levee system. "It's a temporary price increase and the prices should be going back to normal", says Mac.
"Much of the Gulf Coast, especially Louisiana, are already at extremely high water levels and so the heavy rains and any potential storm surge will lead to risky flash flooding", Jill Trepanier, an expert at Louisiana State University, said in a statement.
The Florida Panhandle has seen double red flags go up in some areas, closing beaches, the weather service said.