2011 Super Outbreak

2011 Super Outbreak
The storm system responsible for the historic tornado outbreak across the Southern United States on April 27
Meteorological history
DurationApril 25–28, 2011
Tornado outbreak
Tornadoes367
(Record for a continuous outbreak in April and worldwide)
Maximum ratingEF5 tornado
Duration3 days, 7 hours, 18 minutes
Highest windsTornadic – 210 mph (340 km/h) (Hackleburg–Phil Campbell) EF5 on April 27)
Lowest pressure990[1] hPa (mbar); 29.23 inHg
Largest hail4.5 in (11 cm)
Saltville, Virginia on April 27
Overall effects
Fatalities324 (+24 non-tornadic); 3,100+ injuries[2][3][4][5]
Damage$10.2 billion (Costliest on record for a tornado outbreak)[6]
Areas affectedSouthern, Midwestern, & Eastern United States
Part of the Tornadoes of 2011

The 2011 Super Outbreak was the largest, costliest, and one of the deadliest tornado outbreaks ever recorded, taking place in the Southern, Midwestern, and Northeastern United States from April 25 to 28, 2011, leaving catastrophic destruction in its wake.[7][8][9][10] Over 175 tornadoes struck Alabama, Mississippi, and Tennessee, which were the most severely damaged states. Other destructive tornadoes occurred in Arkansas, Georgia, Kentucky, Louisiana, New York, and Virginia, with storms also affecting other states in the Southern and Eastern United States. In total, 367 tornadoes were confirmed by NOAA's National Weather Service (NWS) and Government of Canada's Environment Canada in 21 states from Texas to New York to southern Canada. Widespread and destructive tornadoes occurred on each day of the outbreak. April 27 was the most active day, with a record 223 tornadoes touching down that day from midnight to midnight CDT (05:00–05:00 UTC). Four of the tornadoes were rated EF5, which is the highest ranking on the Enhanced Fujita scale; typically these tornadoes are recorded no more than once a year.[9]

In total, 348 people were killed as a result of the outbreak, including 324 tornado-related deaths across six states and 24 fatalities caused by other thunderstorm-related events such as straight-line winds, hail, flash flooding or lightning.[11][12] In Alabama alone, 238 tornado-related deaths were confirmed by the Storm Prediction Center (SPC) and the state's Emergency Management Agency.[2][11] April 27's 316 fatalities were the most tornado-related fatalities in the United States in a single day since the "Tri-State" outbreak on March 18, 1925 (when at least 751 people were killed).[13][14][15][16] Nearly 500 preliminary local storm reports were received for tornadoes over four days, including 292 in 16 states on April 27 alone.[17] This event was the costliest tornado outbreak in United States history, with total damage reaching $10.2 billion (equivalent to $14 billion in 2023).[18] In 2023, tornado expert Thomas P. Grazulis created the outbreak intensity score (OIS) as a way to rank various tornado outbreaks. The 2011 Super Outbreak received an OIS of 378, making it the second most intense tornado outbreak in recorded history behind only the 1974 Super Outbreak.[19]

  1. ^ "WPC surface analysis zoom, pan, animation and archives". wpc.ncep.noaa.gov. Archived from the original on November 18, 2022. Retrieved June 13, 2023.
  2. ^ a b "Annual Fatal Tornado Summaries". Storm Prediction Center. National Oceanic and Atmospheric Administration. Archived from the original on June 13, 2011. Retrieved November 1, 2011.
  3. ^ "Tornado victims seek comfort in Sunday services". CBS News. May 1, 2011. Archived from the original on April 27, 2023. Retrieved April 27, 2023.
  4. ^ "Heavy Rain/Severe Weather on April 23–27, 2011". National Weather Service in Little Rock, Arkansas. National Oceanic and Atmospheric Administration. April 27, 2011. Archived from the original on April 30, 2011. Retrieved April 28, 2011.
  5. ^ "Top federal officials tour, promise help to tornado-ravaged South". CNN. May 1, 2011. Archived from the original on November 9, 2012. Retrieved May 1, 2011.
  6. ^ "Billion-Dollar Weather and Climate Disasters". National Centers for Environmental Information. Archived from the original on January 10, 2023. Retrieved May 9, 2023.
  7. ^ Knox, John A.; Rackley, Jared A.; Black, Alan W.; Gensini, Vittorio A.; Butler, Michael; Dunn, Corey; Gallo, Taylor; Hunter, Melyssa R.; Lindsey, Lauren; Phan, Minh; Scroggs, Robert; Brustad, Synne (2013). "Tornado Debris Characteristics and Trajectories During the 27 April 2011 Super Outbreak as Determined Using Social Media Data". Bulletin of the American Meteorological Society. 94 (9): 1371–1380. Bibcode:2013BAMS...94.1371K. doi:10.1175/BAMS-D-12-00036.1.
  8. ^ j, Sanders; j., Sanders (January 8, 2013). "Abstract: Comparative Analysis of Multiple Tornado Tracks During Severe Weather Outbreaks: 2011 Super Outbreak, Alabama (93rd American Meteorological Society Annual Meeting)". confex.com. Archived from the original on December 8, 2015. Retrieved October 12, 2015.
  9. ^ a b "April 2011 tornado information". National Oceanic and Atmospheric Administration. May 9, 2011. Archived from the original on May 11, 2011. Retrieved May 16, 2011.
  10. ^ "New Tornado Records Set for Alabama". National Weather Service in Birmingham, Alabama. National Oceanic and Atmospheric Administration. Archived from the original on August 6, 2011. Retrieved November 1, 2011.
  11. ^ a b "Number of weather related fatalities 236" (PDF). Alabama Emergency Management Agency (Press release). State of Alabama. April 30, 2011. Archived from the original (PDF) on December 24, 2016. Retrieved April 30, 2011.
  12. ^ Jason Morton (May 5, 2011). "List of missing at 25". The Tuscaloosa News. Archived from the original on September 27, 2012. Retrieved May 5, 2011.
  13. ^ "Famous Large Tornado Outbreaks In The U.S." National Weather Service in Milwaukee/Sullivan, Wisconsin. National Oceanic and Atmospheric Administration. Archived from the original on November 22, 2011. Retrieved November 1, 2011.
  14. ^ "Harrowing stories emerge from storm's aftermath". CNN. April 30, 2011. Archived from the original on November 9, 2012. Retrieved April 30, 2011.
  15. ^ "South mourns victims of deadly tornadoes". CBS News. April 30, 2011. Retrieved May 1, 2011.
  16. ^ "Twister Outbreak Is Second Deadliest in History". NBC News/AP News and Reuters (jointly produced article). April 30, 2011. Archived from the original on February 15, 2020. Retrieved April 30, 2011.
  17. ^ Cite error: The named reference Storm Reports April 27 was invoked but never defined (see the help page).
  18. ^ "Billion-Dollar Weather and Climate Disasters: Events". National Centers for Environmental Information. 2020. Archived from the original on August 11, 2021. Retrieved April 28, 2020.
  19. ^ "Significant Tornadoes outbreaks preview". www.tornadoproject.com. Archived from the original on August 29, 2023. Retrieved September 13, 2023.