Today, September 20,2011,  NOAA’s National Weather Service released its final assessment report on the May 22 tornado that struck Joplin, Mo. The report identifies best practices and makes recommendations to help save more lives during future violent tornadoes. Most importantly, the assessment emphasizes that people must be prepared to take immediate action when a warning is issued.

“The tornado that struck Joplin offers important lessons about disaster preparedness,” said National Weather Service Director, Jack Hayes, Ph.D. “Tragically, despite advance tornado outlooks, watches and warnings, 159 people died and more than 1,000 were injured. At NOAA we will do all we can – working with our partners throughout the weather enterprise and emergency management – to reduce the impact of similar disasters.”

Within days of the tragedy, Hayes sent an assessment team to Joplin to examine warning and forecast services provided to the community, warning communications, community preparedness and the public’s response to tornado warnings.

Radar animation of Joplin tornado on May 22, 2011.

View animation here. (Credit: NOAA)

The team determined that a number of factors contributed to the high death toll. Through interviews with more than 100 Joplin residents, the team found that societal response to warnings is highly complex and involves a number of factors, such as risk perception, overall credibility of warnings and warning communications.

The report includes a number of key recommendations:

• Improve warning communications to convey a sense of urgency for extreme events. This will compel people to take immediate life-saving action;
• Collaborate with partners who communicate weather warnings to develop GPS-based warning communications, including the use of text messaging, smart phone apps, mobile communications technologies, in addition to upgrades to the Emergency Alert System and NOAA Weather Radio;
• Collaborate more throughout the weather enterprise to ensure that weather warning messages sent via television, radio, NOAA Weather Radio, local warning systems such as sirens – are consistent to reduce confusion and stress the seriousness of the threat; and
• Continue to increase community preparedness.

Hayes directed National Weather Service staff to move forward to implement the recommendations as soon as possible. The high death toll from the tornado was also catalyst for the August 17 launch of “Weather-Ready Nation”. Building a Weather-Ready Nation will require the efforts of the entire weather enterprise - the National Weather Service, the private weather industry, emergency managers, partners and academia - to provide better information to the public so that they can make better decisions to save lives and livelihoods.

Image showing damage from the tornado that hit Joplin, Mo., on May 22, 2011.

Download here. (Credit: NOAA)

This was the single deadliest tornado in U.S. history since modern record-keeping began in 1950. Rated EF-5 on the Enhanced Fujita scale, this mile-wide tornado was the largest and most powerful type, and it traveled 22 miles on the ground.

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