The Southeastern United States, extending from South Florida to Louisiana and areas inland, was severely affected by Hurricane Katrina, which caused many deaths and billions in damages. After developing on August 23, Katrina made landfall near the border of Broward and Miami-Dade counties with winds on August 25. After emerging from the state, Katrina intensified into one of the strongest Atlantic hurricanes, becoming a Category 5 on the Saffir–Simpson scale. It weakened slightly before making landfall on August 29, 2005. It struck the Gulf Coast as a Category 3 hurricane. It moved ashore near the border of Louisiana and Mississippi and weakened as it moved inland, dissipating on August 31.

In Florida, the storm affected the southern portion of the state and in the panhandle. While it was crossing the state, the hurricane's convection was asymmetrical, primarily located to the south and east of the center. As a result, high rainfall totals occurred in the Miami area, peaking at in Perrine. The rains caused flooding, and the combination of rains and winds downed trees and power lines, leaving 1.45 million people without power. Damage in South Florida was estimated at $523 million (2005 USD), mostly as a result of crop damage. Further south, the hurricane spawned a tornado in the Florida Keys. In the island chain, Katrina caused heavy rainfall and gusty winds. The storm produced a storm surge in Pensacola along the panhandle. High waves caused beach erosion and closed nearby roadways. There were five tornadoes in northwestern Florida. Damage was estimated along the panhandle at $100 million. Throughout the state, the hurricane killed 14 people, of which 6 were directly related to the storm's effects. Due to damage from Katrina, 11 Florida counties were declared federal disaster areas.

Hurricane Katrina's winds and storm surge reached the Mississippi coastline on the morning of August 29, 2005, US Department of Commerce, "Service Assessment: Hurricane Katrina August 23–31, 2005" (June 2006), pp. 10/16, NOAA’s National Weather Service, Silver Spring, MD, web: NWS-Katrina-PDF : page 7 (storm surge 26–28 ft), p. 50: "Appendix C: Tornado Reports Associated with Hurricane Katrina" (62 tornadoes). beginning a two-day path of destruction through central Mississippi; by 10a.m. CDT on August 29, 2005, the eye of Katrina began traveling up the entire state, only slowing from hurricane-force winds at Meridian near 7p.m. and entering Tennessee as a tropical storm.

Many coastal towns of Mississippi (and Louisiana) had already been obliterated, in a single night. In Mississippi, towns near the eye-path at night included: Pearlington, Lakeshore, Clermont Harbor, Waveland, Bay St. Louis, Pass Christian, and Long Beach, MS; in Louisiana, the towns included Buras, Triumph, Meraux, and Chalmette, Louisiana. Hurricane-force winds reached coastal Mississippi by 2a.m. and lasted over 17 hours, spawning 11 tornadoes (51 in other states) and a storm surge flooding inland. Many, unable to evacuate, As flood waters rose, many streets became swamped and impassable. Emergency crews rescued over 100 people, from rooftops or trees, in Mississippi. survived by climbing to attics or rooftops, or swimming to higher buildings and trees. The worst property damage from Katrina occurred in coastal Mississippi, where all towns flooded over 90% in hours, and waves destroyed many historic buildings, with others gutted to the 3rd story. Afterward, 238 people died in Mississippi, and all counties in Mississippi were declared disaster areas, 49 for full federal assistance."FEMA-1604-DR Mississippi Disaster Declaration as of October 27, 2005" (map), FEMA, ITS Mapping and Analysis Center, Washington, DC, 2005-10-27, webpage: FEMA-1604-pdf ."Information Relating to the Federal Appropriations for Katrina Recovery" (January 6, 2006), Office of the Governor, Mississippi, webpage: "Mississippi Governor Haley Barbour" GBarbour-Rec . Regulations were changed later for emergency centers and casinos. The emergency command centers were moved higher because all 3 coastal centers flooded at above sea level. Casinos were allowed on land rather than limited to floating casino barges as in 2005.

More than one million people in Mississippi were affected, and almost 6 months later, the extent of the devastation in Mississippi was still described as "staggering" in USA Today on February 16, 2006: "SIX MONTHS AFTER KATRINA: AN OVERVIEW" (short summary), Office of the House Democratic Leader Nancy Pelosi, February 28, 2006, file: HouseGov-Katrina6. "The Mississippi Gulf Coast has been devastated. The extent of the devastation in Mississippi is also staggering. Since Katrina hit, more than half a million people in Mississippi have applied for assistance from FEMA. In a state of just 2.9 million residents, that means more than one in six Mississippians have sought help.

Background

In the preceding 2004 season, Florida was affected by four hurricanes, including hurricanes Frances and Jeanne which hit Martin County and caused billions in damage. In July 2005, hurricanes Cindy and Dennis hit the northern gulf coast, the latter as a Category 3 hurricane on the Saffir-Simpson scale.

The origins of Katrina were from a tropical depression that formed over the Bahamas on August 23. Moving generally westward, it intensified into a hurricane, and Katrina made its first landfall near the border of Miami-Dade and Broward counties with winds of around , at 22:30 UTC on August 25. It briefly weakened into a tropical storm over Florida, but restrengthened in the Gulf of Mexico, becoming a Category 5 on August 28. Katrina weakened slightly as it approached the northern gulf coast, making landfall in southeastern Louisiana as a Category 3 hurricane on August 29. Shortly thereafter, Katrina made another landfall near the border of Louisiana and Mississippi. It remained a hurricane as far inland as Meridian, Mississippi, when it weakened into a tropical storm. Katrina weakened further into a tropical depression near Clarksville, Tennessee, and later got absorbed by a cold front in the Great Lakes region.

Preparations

On August 24, the National Hurricane Center (NHC) first started issuing tropical cyclone watches and warnings for the southeastern United States. The agency issued a tropical storm warning and a hurricane watch from Florida City to Vero Beach, with a tropical storm watch southward to the Seven Mile Bridge. About 25 hours before Katrina made landfall, the tropical storm watch was extended northward to Titusville, and a tropical storm warning and a hurricane watch was issued for Lake Okeechobee. Early on August 25, a hurricane warning was issued from Florida City to Vero Beach and for Lake Okeechobee. In southeastern Florida, the lead time for the hurricane watch and warning occurred 31.5 and 19.5 hours before landfall, respectively; both were 16.5 hours less than the desired lead time. A tropical storm warning was also issued from Florida Key, southward through the Florida Keys to the Dry Tortugas, and northward along the western coast to Longboat Key. The warning in the Florida Keys occurred only nine hours before the onset of tropical storm force winds.

On August 25 while Katrina was over Florida, Governor Jeb Bush declared a state of emergency. A day later, Louisiana Governor Kathleen Blanco followed suit and declared a state of emergency, and on August 27, Mississippi Governor Haley Barbour did the same for his state. Alabama Governor Bob Riley declared a state of emergency on August 28. While the hurricane was still over water, President George W. Bush declared a disaster area for Louisiana and Mississippi, allocating resources from the Federal Emergency Management Agency (FEMA).

Before Katrina moved ashore Florida, schools and businesses were closed in the Miami area. Cruise ships altered their paths due to seaports in southeastern Florida closing. Officials in Miami-Dade County advised residents in mobile homes or with special needs to evacuate. To the north in Broward County, residents east of the Intracoastal Waterway or in mobile homes were advised to leave their homes. Evacuation orders were issued for offshore islands in Palm Beach County, and for residents in mobile homes south of Lantana Road. Shelters were opened across the region. Officials closed the Miami International Airport, Fort Lauderdale – Hollywood International Airport, Key West International Airport, and Florida Keys Marathon Airport due to the storm. In Monroe and Collier counties, schools were closed, and a shelter was opened in Immokalee. On August 25, Florida's Emergency Operations Center was activated in Tallahassee to monitor the progress of the hurricane.

Also on August 25, when Hurricane Katrina crossed the southern tip of Florida, government offices in Mississippi had already discussed emergency evacuation plans for days. On August 26, the Mississippi National Guard was activated, raising the level of concern, and on August 27, the state government activated its Emergency Operations Center, and local governments began issuing evacuation orders: the Mississippi Emergency Management Agency (MEMA)Mississippi Emergency Management Agency (MEMA), website: MEMA-web. advised not opening shelters in coastal counties. However, on August 28, the Red Cross also opened shelters in coastal counties, and by 7:00 pm, 11 counties and eleven cities issued evacuation orders, a number which increased to 41 counties and 61 cities before the following morning, when Katrina came ashore. Moreover, 57 emergency shelters were established on coastal communities, with 31 additional shelters available to open if needed.

The NHC issued a hurricane watch on August 27 from Intracoastal City, Louisiana to the Florida/Alabama border. This was modified to a hurricane warning from Morgan City, Louisiana to the Florida/Alabama border, with a tropical storm warning westward to Intracoastal City, and another tropical storm warning extending eastward to Destin, Florida. On August 28, the National Weather Service in Slidell, Louisiana issued a bulletin predicting "devastating" damage rivaling the intensity of Hurricane Camille."Urgent Weather Message." National Weather Service/New Orleans, Louisiana. August 28, 2005. Mandatory evacuations were issued for large areas of southeast Louisiana as well as coastal Mississippi and Alabama.Staff Writer. "New Orleans flees as Katrina approaches Gulf Coast." USA Today. August 28, 2005. Officials also issued mandatory evacuations for portions of the Florida panhandle.

By 4:30 am. CDT, on August 29, 2005, just hours before Hurricane Katrina landfall, many shelters in Mississippi were full to capacity, including many Red Cross shelters, the Jackson Coliseum (which allowed pets), and five special-needs shelters. The shelters had filled within 24 hours of opening.

Since the evacuation was not total, many people survived the storm tide by climbing into the second-floor attic, or knocking out walls and ceiling boards to climb onto the roof or nearby trees.Unlike some suburbs, many towns in Mississippi had numerous strong trees, such as old oak trees, higher than roof-tops. Tree trunks remained standing,The tree trunks, after losing small branches, were narrow compared to wide walls battered by waves, boats and debris. even near the beaches, where many houses were leveled. Other people had swum to taller buildings or trees.Burdeau, Cain. "Waveland practically wiped off map by force of Katrina ." WWL-TV. August 31, 2005. Over 100 people were rescued from roof tops and trees in Mississippi.