MEMPHIS, TN (WMC) - The tornado outbreak from April 25 to April 28 in 2011 was one of the deadliest and costliest events on record in the United States.
In just those four days, 324 people were killed by tornadoes with most of those being on April 27 in the state of Alabama.
The ingredients for severe weather aligned perfectly with a plume of Gulf moisture over the southeast, strong shear (change in winds with height) and high instability. A cold front provided the spark needed to create multiple severe thunderstorms that spawned 360 tornadoes. On the most deadly day on April 27, there were 216 confirmed tornadoes.
There were multiple tornadoes reported in the Mid-South on April 25, 26 and 27. The strongest tornado was an EF-3 in Lafayette County, MS with 140 mph winds. There were multiple EF-0 and EF-1 tornadoes in Arkansas, Tennessee and Mississippi, including in the counties of Tippah and Alcorn in Mississippi.
WHY IT WAS SO DEADLY
Although there was ample warning several days out, no one could have imagined the destruction and magnitude of these tornadoes. On the EF scale, an EF-5 is the highest and causes almost total destruction. On average, there may be one of these EF-5 tornadoes in a year. On April 27, there were four EF-5 tornadoes.
These result in nearly complete removal of buildings from the foundation. Unfortunately, the only true safe place would be in an underground storm shelter during this type of tornado. In addition, there was an early morning line of storms that knocked out power to much of the area in Alabama. Many people thought the threat was over after the morning storms and let their guard down, but the main line did not arrive until later in the afternoon. This false sense of safety mixed with the lack of available communication resulted in a deadly combination.
When there is a threat for severe weather, we always recommend having multiple ways to get weather information. Download the WMC Weather App for warnings and additional information on severe weather threats from your First Alert Weather Team.