Hurricane Katrina

Storm History

Since the 1980s, hurricane tracking and forecasting have improved significantly, as has the ability to communicate to more people through a variety of media. Tracking the development and movement of Hurricane Katrina and the early messages [Page 380]of its likely landfall locations epitomize our current capabilities with respect to storm warnings.

The storm began as a tropical depression on August 22, over the southeastern Bahamas, and intensified to become a tropical storm (see Table 1) on August 24, at which time it was named Katrina. The storm reached hurricane status the afternoon of Thursday, August 25, as it approached landfall on the southeastern coast of Florida. Hurricane Katrina made its first U.S. landfall in the Miami area at 6:30 p.m. on August 25, with maximum sustained winds of about 81 miles per hour (mph). Very heavy rainfall occurred as the storm moved across southern Florida, bringing over 12 inches of precipitation in some locales. Six people died in Florida from the direct effects (wind and water) of Hurricane Katrina. Katrina weakened back to tropical storm status before entering the Gulf of Mexico early on August 26.

The storm rapidly regained hurricane status after reaching the Gulf of Mexico. At that time, gulf waters were exceptionally warm, providing Katrina with the energy to intensify. By Friday evening, August 26, Katrina was a Category 2 storm.

Once in the Gulf of Mexico, Hurricane Katrina intensified rapidly, becoming a Category 3 hurricane with 115 mph winds by the morning of August 27. In addition to increasingly strong winds, the storm nearly doubled in size on August 27, with tropical storm force winds as far as 160 miles from the center. The hurricane turned toward the northwest and strengthened to a Category 5 storm on August 28, with winds at 167 mph; it reached a 173 mph peak intensity later that day, about 195 miles southeast of the Mississippi River delta. Katrina became very large, with hurricane force winds extending about 100 miles from the storm center and tropical storm force winds to about 230 miles.

Hurricane Katrina's path turned northward early on Monday, August 29. The storm weakened considerably due to internal storm changes and made landfall in Louisiana's Plaquemines Parish, as a strong Category 3 storm with estimated maximum sustained winds of about 126 mph. Hurricane strength often is judged by atmospheric pressure in the center of the storm, as well as by wind speeds; low pressures are associated with stronger storms. Central pressure of Hurricane Katrina at the time of Louisiana landfall was 920 millibars, a very low pressure, and the third lowest on record for hurricane landfalls in the United States. The storm center crossed over the delta area and made its final landfall near the boundary between Louisiana and Mississippi with an estimated top sustained wind speed of about 121 miles per hour. Although Katrina had weakened to just below Category 4 status, making landfall as a strong Category 3 storm, the size of the hurricane remained very large, with hurricane and tropical storm force winds extending out to about 200 miles or more from the storm center.

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