Tropical Storm Barry is expected to reach hurricane strength before it makes landfall early Saturday morning, according to the National Weather Service.
As of 2 a.m. ET Saturday, the storm was moving west-northwest at 3 miles per hour as it approached Louisiana, with maximum sustained winds at 65 mph, the weather service reported. The storm was about 70 miles south of Morgan City, La.
Meanwhile, forecasters were downgrading a predicted rise for the Mississippi River. They said Friday night that the river would rise about 2 feet lower than originally expected and most likely will not break over its levees.
The NWS said the river will likely rise as high as 17.1 feet by Monday in New Orleans. The levees protecting the city range from about 20 to 25 feet high. Forecasters had earlier thought the river would crest Saturday at about 19 feet in New Orleans.
TROPICAL STORM BARRY PROMPTS STORM SURGE, FLOOD WARNINGS: WHY IS NEW ORLEANS AT AN INCREASED RISK?
Barry’s torrential rains are expected to test New Orleans’ post-Katrina flood defenses. The storm is forecast to dump 10 to 20 inches of rain on New Orleans through Sunday. Residents have not been advised to evacuate. Instead, officials said to stay indoors, have about three days’ worth of supply, and make sure neighborhood flood drains remain unblocked to allow water flow.
Hurricane Katrina caused catastrophic flooding in New Orleans in 2005, and was blamed for more than 1,800 deaths in Louisiana and other states, by some estimates.
In Katrina's aftermath, the Army Corps of Engineers began a multibillion-dollar hurricane-protection system that isn’t complete. The work included repairs and improvements to some 350 miles of levees and more than 70 pump stations that are used to remove floodwaters.
President Trump has already declared a state of emergency for Louisiana, authorizing federal disaster relief efforts. And about 10,000 people in Plaquemines Parish on Louisiana's low-lying southeastern tip were ordered evacuated on Thursday.
New Orleans is particularly vulnerable to flooding because of its low elevation. Only about half the city is above sea level — a drop from what once was 100 percent, according to the Atlantic, which cited human activity as a primary reason for the drop.
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Louisiana Gov. John Bel Edwards warned that the storm's impact, coupled with the already-high Mississippi River –which has been swelled by heavy rain and snowmelt upriver this spring — could be a dangerous combination.
“There are three ways that Louisiana can flood: storm surge, high rivers and rain,” Edwards said. “We're going to have all three.”
Fox News' Paulina Dedaj, Madeline Farber and the Associated Press contributed to this report.