Hurricane Isaac barreled into the northern coast of the Gulf of Mexico on Tuesday, bringing storm surges, heavy rains, stiff winds, flooding, and threats of tornadoes. The Category 1 hurricane, which struck parts of Alabama, Louisiana, and Mississippi, was expected to reach New Orleans late this evening, seven years to the day that Hurricane Katrina slammed into the city. One of the most destructive storms in United States history, Katrina killed about 1,800 people and caused about $100 billion in damage. About 80 percent of New Orleans was flooded as parts of the city’s system of levees (flood barriers) failed. Most of the approximately 1,500 Louisianians who died because of the storm were from New Orleans.
Isaac made its first landfall at about 7:45 p.m. (EDT), about 95 miles (153 kilometers) south of New Orleans in Plaquemines Parish. The storm then wobbled westward and back into the gulf but returned for a second landfall at 3 a.m. (EDT) on Wednesday, near Port Fourchon, about 60 miles (97 kilometers) south of New Orleans. Heavy rainfall and storm surges along the Gulf Coast in Louisiana and Mississippi caused flooding as deep as 14 feet (4 meters) in some areas, sending residents who chose not to evacuate to the rooftops of their houses.
By midday Tuesday, the already slow-moving storm had essentially stalled, leading forecasters to predict that heavy rains would pound the area for several days. New Orleans could receive up to 20 inches (51 centimeters), said an official with the National Weather Service. Residents and officials in New Orleans were keeping a close eye on the city’s levees and pumps, which had undergone a $14-billion federal upgrade after the flood protection system had failed catastrophically during the much-stronger Hurricane Katrina.
Surface winds feed heat energy and water vapor into a hurricane. A core of warm air maintains a zone of low pressure near the surface, drawing more air into the hurricane. Much rain falls from tall bands of clouds called the eyewall and rainbands. This illustration is not to scale. The cloud structure is about 150 miles (240 kilometers) across and 8 miles (13 kilometers) high.
World Book illustrations by Bruce Kerr
Ahead of Isaac’s arrival, the governors of Alabama, Louisiana, and Mississippi ordered mandatory evacuations in some counties. The next day, U.S. President Barack Obama declared a state of emergency in Louisiana. National Guard troops were placed on stand-by alert to help communities affected by the storm. New Orleans officials also declared a state of emergency and provided buses for people to wished to leave their homes voluntarily.
Before hitting the Gulf Coast, Isaac–then a tropical storm–had lashed central and southern Florida with heavy rains and strong winds. The storm also caused the deaths of 24 people in Haiti and widespread damage along that country’s southern coast. The storm left 5 people dead in neighboring Dominican Republic.
Read even more about Hurricanes and other natural phenomena with World Book’s Natural Disasters!