Louisiana's governor, John Bel Edwards, called the disaster a "historic, unprecedented flooding event" and declared a state of emergency.

[5] Early on August 11, a mesoscale convective system flared up in southern Louisiana around a weak area of low pressure that was situated next to an outflow boundary.

It remained nearly stationary, and as a result, torrential downpours occurred in the areas surrounding Baton Rouge and Lafayette.

[7] The Washington Post noted that the "no-name storm" dumped three times as much rain on Louisiana as Hurricane Katrina.

According to the National Weather Service Hydrometeorological Design Studies Center, the amount of rainfall in the hardest-hit locations had a less than 0.1 percent chance of happening or was a (less than) 1-in-1,000-year event.

A follow-on peer-reviewed paper indicates that the catastrophic flood in Louisiana was a result of intense precipitation produced by a slow-moving, tropical, low-pressure system interacting with an eastward-traveling baroclinic trough to the north.

[10] Analyses point towards the tendency for more and perhaps stronger upper-level troughs propagating out of the western U.S. in summer; these have an increasing potential to cross paths with low-pressure systems that form around the Gulf Coast.

Regional simulations suggest that the climate warming since 1985 may have increased the event precipitation (August 11–14, 2016) on the order of 20%.

[10] Rainfall like this and the emergency help needed after the flooding subsides are straining the federal system for aid to states.

[11] By August 15, more than ten rivers (Amite, Vermilion, Calcasieu, Comite, Mermentau, Pearl, Tangipahoa, Tchefuncte, Tickfaw, and Bogue Chitto) and many more had reached a moderate, major, or record flood stage.

[14] Water levels began to slowly recede by August 15, though large swaths of land remained submerged.

[23] Many boat-owning residents of Louisiana and Mississippi, together with other volunteers, formed an informal rescue service known as the Cajun Navy and navigated through flooded areas to answer calls for help that they received via social media.

[28] Flash flooding swamped a 7-mile (11 km) section of Interstate 12 between Tangipahoa Parish and Baton Rouge, stranding 125 vehicles.

State police and the National Guard used high-water vehicles to rescue trapped motorists, but many remained stuck for over 24 hours.

[34][35] Singer Beyoncé, along with sister Solange and Kelly Rowland, held an event that raised more $4 million for those affected by the floods in Baton Rouge.

[39] Randy Jackson and Harry Connick Jr. were scheduled to host a benefit concert at the Baton Rouge River Center Theatre on September 5, featuring over a dozen artists, and all proceeds went to the American Red Cross Louisiana Flood Relief fund.

[47] Following a school board meeting on Thursday, September 9, Assistant Superintendent Stephen Parill announced the "known and confident updates" for the 2016 Academic Calendar.

[48] For the entire state, superintendent John White said that at least 22 schools had heavy damage and will need time to recover.

[52] Transportation was a challenge for many districts across the state, as many kids were displaced from their homes and many school buses were damaged from flood water.

[4] FEMA, which has stepped in to help homeowners without flood insurance, has declared these 20 parishes as federal disaster areas: Acadia, Ascension, Avoyelles, East Baton Rouge, East Feliciana, Evangeline, Iberia, Iberville, Jefferson Davis, Lafayette, Livingston, Pointe Coupee, St. Helena, St. Landry, St. Martin, St. Tammany, Tangipahoa, Vermilion, Washington, and West Feliciana.

[60] Homeowners with damage from the floods in those parishes are eligible for up to $33,000 in federal disaster aid and so far around 102,000 people have applied for help.

[61][62][63] For business continuity and community rebuilding, private mobile flood recovery centers have also been made available, including a 10-piece modular building complex used in Baton Rouge by FEMA as a portable school for children of displaced families who moved north from New Orleans after Hurricane Katrina.