All Weather News

10th Anniversary of April 27, 2011 Super Outbreak

27 Apr 2021, 12:37 am

April 27 marks the anniversary of an infamous day in the southeast. Severe weather, specifically dangerous and intense tornadoes, changed the lives of thousands forever. Meteorologist David Neal recounts his experience that fateful day.

COURTESY: NOAA/NCDC

Between April 25th and 28th, one of the largest, deadliest, and most destructive tornado outbreaks in U.S. history struck the eastern third of the nation. A strong upper level low pressure system moved across the northern Plains and the associated cold front tapped into a very moist and unstable atmosphere, producing an extraordinary tornado outbreak across the southeastern United States. NOAA’s preliminary estimate is that there were 305 tornadoes that hit from Texas to New York, with an estimated 190 tornadoes touching down over a 24-hour period on the 27th and 28th. At the time this report was released in early May, storm surveys continued to be conducted and the final tornado counts as well as fatalities/injuries continued to be unresolved. However, the current count of strong tornadoes was three EF-5s, 12 EF-4s, and 21 EF3s. In comparison, the April 1974 Super Outbreak had six F-5s, 23 F-4s, and 35 F-3s.

Preliminary analysis places the death toll near 350 people for the entire outbreak, mostly across the state of Alabama. This surpasses the death toll and tornado counts of the April 1974 super outbreak, which had 148 tornadoes and 315 deaths associated with it. One of the EF-5 tornadoes of the outbreak occurred across northern Mississippi, near Smithville. The tornado had estimated winds of 205 mph (330 km/hr), destroyed 18 homes, and killed 14 people. This was the first EF-5 tornado since the tornado that struck Parkersburg, Iowa in February 2008. The second EF-5 tornado of the outbreak occurred across northern Alabama and southeastern Tennessee. The tornado had a continuous path length of 132 miles (212 km) and was up to 1.25 miles (2 km) wide at certain points. Thousands of homes and other structures were destroyed or heavily damaged. The number of fatalities and injuries were unknown. The most destructive tornado of the outbreak occurred across central Alabama, hitting the cities of Tuscaloosa and Birmingham, and was deemed a strong EF-4. The violent tornado had winds of up to 190 mph (306 km/hr), a maximum path width of 1.5 miles (2.4 km), and was on the ground for approximately 80.3 miles (129 km). Preliminary estimates report there were over a thousand injuries and 65 fatalities with this single tornado. In Tuscaloosa alone, it is estimated that it will cost up to 100 million US dollars just to remove debris from the city. These numbers will likely be revised upwards, once the final surveys are completed. This tornado could potentially surpass the F-5 tornado which hit Moore, Oklahoma in May 1999 as the most expensive tornado to ever hit the United States. The supercell thunderstorm that spawned this tornado tracked over 380 miles (612 km) from Mississippi to North Carolina, spawning several tornadoes along its way. According to analysis by NOAA, this tornado was the deadliest tornado since May 25, 1955 when 80 people were killed by a tornado in Kansas.

The outbreak has a whole also produced staggering fatality statistics. The April 26-28, 2011 period had the most people killed during a single tornado outbreak since 454 people were killed in the April 5-6, 1936 tornado outbreak. April 27, 2011 marks the deadliest tornado day since March 18, 1925 when 747 people were killed by tornadoes.

 

TORNADO AWARENESS

Even during the crisis, amid so many tornadoes, the National Weather Service maintained an average warning lead time of 24 minutes, allowing many families to escape or prepare for the disaster. To make use of these warnings yourself, pay attention to the severe weather alerts issued over your radio, television, and cellular devices. These are life-saving announcements and it’s critical to understand their instructions.

A watch means that there is potential for dangerous weather to affect your area. These are broadcast at least 12 hours prior to when the event is likely to take place. Warnings, however, are issued when severe weather is imminent or already occurring.

NOAA Weather Radio is another critical source for emergency information. With a special, battery-powered receiver that can be acquired from most hardware stores, you can tune into this 24/7 radio station even in the middle of a power outage. They broadcast emergency information on everything from natural disasters to oil spills to public safety concerns, such as AMBER alerts.

For more information on how you can prepare yourself, your family, and your friends for tornadoes and severe weather, visit Ready.gov.

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