The National Weather Service bulletin for the New Orleans region of 10:11 a.m., August 28, 2005 was a vividly worded release issued by the local Weather Forecast Office in Slidell, Louisiana warning of the devastation that the Gulf Coast of the United States could experience as a result of Hurricane Katrina. Partly due to this bulletin, people in southeastern Louisiana and southern Mississippi, those most affected by the storm, followed evacuation orders more closely, resulting in fewer deaths.
On the evening of August 25, 2005, Hurricane Katrina made landfall as a Category 1hurricane near the Miami-Dade – Broward county line in southern Florida and weakened into a tropical storm as a result. The next morning, after passing over the state, Tropical Storm Katrina moved into the Gulf of Mexico, strengthened back to hurricane strength, and from the influence of the warm waters from the Loop Current, began rapid deepening.[1]
At 11:00 p.m. EDT August 26, approximately 56 hours before Katrina's landfall near Buras, Louisiana, the National Hurricane Center had predicted that the New Orleans metropolitan area could face a direct hit by the storm.[2] As New Orleans is on the Mississippi Riverdelta and much of the city is below sea level, a strong hurricane could have a devastating effect on the city. Previous warnings, such as the one made by the Houston Chronicle in 2001, told of a disaster that "would strand 250,000 people or more, and probably kill one of 10 left behind as the city drowned under 20 feet of water" following a severe hurricane landfall on the city.[3] The National Hurricane Center's director, Max Mayfield, said the Mississippi/Louisiana area has "the greatest potential for nightmare scenarios," and that this has been known for at least the three decades he has worked at the NHC.[4] Other publications, such as Popular Mechanics,[5]Scientific American,[6] and The Times-Picayune[7] predicted doomsday situations in which a sinking city would drown and its residents would be left homeless.
In 1965, Hurricane Betsy made landfall just south of New Orleans, causing widespread flooding in the city. As a result, a system of levees was authorized by Congress to handle future storm events. However, the protection given by this system was limited to hurricanes up to Category 3 intensity on the Saffir-Simpson Hurricane Scale.[8]
Three days before Katrina's second and third landfalls, the National Hurricane Center began predicting that the storm would make landfall as a major hurricane.[2] By the next morning, August 27, the NHC gave out a hurricane watch that included the New Orleans metro area,[9] which was upgraded to a hurricane warning by 10:00 p.m. that same evening.[10] At this point, Katrina was a Category 3 hurricane with 115 mph (185 km/h) winds and about 335 miles (540 km) to the south-southeast of the Mississippi River's mouth.[10]
That night, the storm strengthened to a Category 5 hurricane with maximum sustained winds of 175 mph (280 km/h) by 10:00 am CDT on August 28.[11] At that time, the Weather Forecasting Office issued an "urgent weather message" describing the destruction Katrina would likely cause in the region:[2]
Bulletin text
At 10:11 a.m. CDT (1511 UTC), Robert Ricks, a meteorologist with the New Orleans/Baton Rouge NWS office, issued the following statement:[12][13]
.HURRICANE KATRINA...A MOST POWERFUL HURRICANE WITH UNPRECEDENTED
STRENGTH...RIVALING THE INTENSITY OF HURRICANE CAMILLE OF 1969.
MOST OF THE AREA WILL BE UNINHABITABLE FOR WEEKS...PERHAPS LONGER. AT
LEAST ONE HALF OF WELL CONSTRUCTED HOMES WILL HAVE ROOF AND WALL
FAILURE. ALL GABLED ROOFS WILL FAIL...LEAVING THOSE HOMES SEVERELY
DAMAGED OR DESTROYED.
THE MAJORITY OF INDUSTRIAL BUILDINGS WILL BECOME NON FUNCTIONAL.
PARTIAL TO COMPLETE WALL AND ROOF FAILURE IS EXPECTED. ALL WOOD
FRAMED LOW RISING APARTMENT BUILDINGS WILL BE DESTROYED. CONCRETE
BLOCK LOW RISE APARTMENTS WILL SUSTAIN MAJOR DAMAGE...INCLUDING SOME
WALL AND ROOF FAILURE.
HIGH RISE OFFICE AND APARTMENT BUILDINGS WILL SWAY DANGEROUSLY...A
FEW TO THE POINT OF TOTAL COLLAPSE. ALL WINDOWS WILL BLOW OUT.
AIRBORNE DEBRIS WILL BE WIDESPREAD...AND MAY INCLUDE HEAVY ITEMS SUCH
AS HOUSEHOLD APPLIANCES AND EVEN LIGHT VEHICLES. SPORT UTILITYVEHICLES AND LIGHT TRUCKS WILL BE MOVED. THE BLOWN DEBRIS WILL CREATE
ADDITIONAL DESTRUCTION. PERSONS...PETS...AND LIVESTOCK EXPOSED TO THE
WINDS WILL FACE CERTAIN DEATH IF STRUCK.
POWER OUTAGES WILL LAST FOR WEEKS...AS MOST POWER POLES WILL BE DOWN
AND TRANSFORMERS DESTROYED. WATER SHORTAGES WILL MAKE HUMAN SUFFERING
INCREDIBLE BY MODERN STANDARDS.
THE VAST MAJORITY OF NATIVE TREES WILL BE SNAPPED OR UPROOTED. ONLY
THE HEARTIEST WILL REMAIN STANDING...BUT BE TOTALLY DEFOLIATED. FEW
CROPS WILL REMAIN. LIVESTOCK LEFT EXPOSED TO THE WINDS WILL BE
KILLED.
AN INLAND HURRICANE WIND WARNING IS ISSUED WHEN SUSTAINED WINDS NEAR
HURRICANE FORCE...OR FREQUENT GUSTS AT OR ABOVE HURRICANE FORCE...ARE
CERTAIN WITHIN THE NEXT 12 TO 24 HOURS.
ONCE TROPICAL STORM AND HURRICANE FORCE WINDS ONSET...DO NOT VENTURE
OUTSIDE!
”
An equally-explicit bulletin was repeated at 4:13 p.m. CDT.[14]
Impact
In the months after the storm, Congress appointed a two-party system committee to look into the response to Hurricane Katrina and the preparations before to its landfall. The committee said that the forecasts given by the National Weather Service were timely, were not responsible for failures in other agencies, and were likely responsible for saving thousands of lives.[4]
During an internal assessment by the National Weather Service, the 10:11 bulletin and its impact were examined. The report called the bulletin "a significant moment for the NWS during Katrina," as its detailed and specific language did not have any previous precedent (though the message was based on a template designed by the Tampa Weather Office in 1990).[2] The strongly-worded statement persuaded people to evacuate, and was highlighted by national news media.[12] As a result, the level of detail was highlighted as an "innovative best practice" in the NWS assessment, which recommended issuing warnings with similar levels of detail in the future.[2][15]
