On the afternoon of Monday, April 28, 2014, a large, destructive, and deadly EF4 tornado caused major damage to Louisville, Mississippi and rural areas south of the town along its path. Killing ten people, injuring 84 people, and causing $126.05 million in damage, the tornado reached a peak width of . The tornado was a part of a significant four-day tornado outbreak that spanned from April 27 to April 30 and was the second strongest tornado of the outbreak, reaching an estimated peak winds of , the strongest being the violent and long-tracked EF4 tornado that tracked through central Arkansas the previous day.
The tornado touched down in northern Leake County, quickly intensifying to high-end EF2 strength, damaging or destroying homes and snapping trees. The tornado intensified further to EF3 strength, destroying chicken farms, damaging homes, and snapping trees. The tornado became violent as trees were shredded and more metal buildings were destroyed. The tornado continued to inflict significant to violent damage, damaging or destroying homes and metal building systems. The tornado weakened down as it entered Louisville. The tornado intensified to low-end EF4 intensity, severely damaging several industrial buildings and destroying numerous homes. For the remainder of the path; an apartment complex was destroyed, several businesses were demolished, and extensive tree damage occurred. The tornado dissipated northeast of Louisville.
Over 300 homes and businesses were destroyed and hundreds were left homeless. Governor of Mississippi Phil Bryant issued a state of emergency for the state prior to the tornado outbreak. President Barack Obama declared a major disaster for Mississippi after the severe weather event. Mississippi National Guardsmen were deployed to towns and communities affected by the tornado outbreak, including Louisville, and a temporary medical care facility was set up as the town's hospital was severely damaged. Several non-profits organizations, including the Samaritan's Purse, assisted in the recovery efforts across multiple states, distributing meals and other essential supplies.
Afterwards, Louisville and other areas received federal grants to assist in the rebuilding efforts, including a law Governor Bryant passed that gave millions to Louisville. Over the next few years after the tornado, several businesses and homes that were destroyed were rebuilt, including the Winston Medical Center and a plywood manufacturing plant, as federal grants were allocated to the city and the county over those few years.
Meteorological synopsis
Setup On April 23, the Storm Prediction Center (SPC) issued a day 6 outlook for potential severe weather, with the SPC noting that a significant, multi-day severe weather event was expected from the central to southern plains to across Dixie Alley. Expectations were that a surface front and dryline should advance into the Mississippi Valley, where several supercells could evolve ahead of the front from Louisiana to as far east as central Tennessee, with tornadoes and large hail possible with the warm sector convection. On April 24, a deep surface cyclone was forecasted to move across easterly through the central plains, and curving frontal position should extend along the Kansas-Missouri border and into southern Texas. Severe thunderstorms development was expected across the warm sector, with winds of knots at the level ejecting across the lower Mississippi Valley into western Tennessee during Monday.
On April 26, a day three moderate risk was issued for a region extending from southwestern Kentucky to central Mississippi. A large, upper-level trough was expected to stall over the central United States, with mid-level speed max at ejecting into parts of the Mid-South and the convergence point of the Mississippi River and Ohio River by the afternoon of April 28. Dew points reaching into the range was expected to be constant across the warm front extending from the Midwest to the Gulf Coast, persisting due to strong low-level shear. Strong diurnal heating was forecasted to occur in areas lacking convective activity to support moderate buoyancy over large parts of the warm sector by the afternoon hours. Low to deep-layer shear was expected to be strong due to the mid-level speed max. The SPC noted that parts of the lower Mississippi Valley had the greatest risk for a high-end severe risk, with numerous storms likely over the area possibly stemming from the regenerative convective clusters along the dryline and convective outflow. With strong wind shear and surface dew points reaching into the range, several supercells and significant tornadoes were likely, along with large hail and damaging winds.
Forecast
On April 28, morning storms that were present over Mississippi, Alabama, and Tennessee began dissipating over time, leaving a well-defined outflow boundary across south-central Tennessee and more diffuse across the northern parts of Mississippi and Alabama. The morning storms dissipating also allowed strong surface heating to start across Louisiana and southwest Mississippi, with further clearing expected to occur. By the afternoon, weakening convective inhibition allowed storm development along or east of the outflow boundary. Mid-level convective available potential energy (CAPE) was expected to be near 2,000 j/kg, with strong bulk shear of , storm-relative helicity at 200-300 ms2/s2, and subtle forcing favored a discrete or cluster supercells mode. With all these variables, at 2:19 p.m. CDT, the SPC upgraded to a high risk for most of central Mississippi and parts of Alabama, accompanied by a 30% hatched risk for strong to violent tornadoes.
At 12:40 p.m. CDT, a particularly dangerous situation tornado watch was issued most of Mississippi, parts of Louisiana, Alabama, and southern Tennessee, with some long-lived supercells capable of producing strong and long-tracked tornadoes. The tornado watch noted that surface based storm were beginning to develop in Louisiana and Mississippi as more clearing occurred and atmospheric destabilization continued, a combination of a moderate ML CAPE and strong deep vertical wind shear supported a broken band of supercells, with an increase in low-level shear expected across central Mississippi, northwest Alabama, and southern Tennessee along the outflow boundary.
By 3:49 p.m. CDT, numerous discrete and clustered supercells were moving northwest from central Mississippi into northwest Alabama, with the damaging Tupelo EF3 tornado already occurring within the past hour as more discrete supercells initiated south into central Mississippi, suggesting that these storms will more likely remain separated for a few more hours, increasing support for long-tracked and significant tornadoes. Local observations showed an expected strengthening of the wind profiles and additional support from the low-level flow associated with surface pressure deepening, boosting storm relative helicity. Strong to violent tornado damage was expected over the next few hours with the most potent supercells.
Tornado summary Formation and initial damage The tornado touched down north of Coosa in Leake County at 3:51 p.m. CDT, snapping and uprooting several softwood trees at mid-range EF1 intensity. The tornado intensified to high-end EF2 strength, with estimated windspeeds of . A mobile home along McGee Town Road was destroyed, three vehicles were thrown and trees were downed. The tornado crossed Highway 25, maintaining high-end EF2 intensity. A metal building system experienced complete destruction. Two homes had majority of their roof ripped, another home nearby had parts of their roof torn off, numerous trees snapped and uprooted and an outbuilding nearby was demolished. The tornado crossed Highway 19, snapping several softwood trees and cause roof damage to a home.
At 3:58 p.m. CDT, the National Weather Service office in Jackson, Mississippi issued a radar indicated particularly dangerous situation tornado warning for Attala, Neshoba, and Winston counties. The tornado weakened to high-end EF1 strength, traversing through rural areas of southern Winston County, snapping and uprooting several trees and overturning a motor home. At the same time, storm chasers reported that a large, multi-vortex tornado was on the ground. With the confirmation that a large and potentially violent tornado was on the ground, NWS upgraded the PDS tornado warning to a tornado emergency for the same aforementioned counties at 4:03 p.m. CDT. Then the tornado intensified slightly, snapping several softwood trees at EF2 intensity along Walter Sisson Road. The tornado turned northeast and crossed Goldman Road, quickly intensifying to mid-range EF3 strength. Peak intensity track and through Louisville
Numerous chicken houses were completely demolished, a one-story brick home along the road was completely unroofed, with parts of the exterior walls collapsing, another home nearby had their roof ripped away and trees were knocked down. The tornado weakened slightly, crossing Plattsburg Road at low-end EF3 intensity. A large home was unroofed and had its exterior walls torn down, with several other homes experiencing significant damage from the tornado. The tornado then abruptly intensified to low-end EF4 strength for the first time as it crossed Hartness Road. Violent forestry damage was inflicted as numerous debarked trees were extensively debarked. Nearby, 12 metal chicken homes were flattened and swept clean off their foundations, and another chicken home was destroyed. The tornado weakened to high-end EF2 intensity, completely ripping away a roof off a home, a double-wide mobile home was destroyed, and several trees and power poles were snapped and toppled over.
The tornado strengthened again to low-end EF4 strength, destroying several more chicken houses at windspeeds of and significantly snapping nearby trees. A guide cell tower nearby was crumpled, with the damage indicator being rated mid-range EF3, though surveyors noted that winds may have been higher. Then, the tornado impacted a small row of homes along Stanley Road, intensifying to peak strength of . A brick home was flattened and blown away, leaving the chimney standing. Another well-constructed brick home nearby was demolished and swept clean, with heavy tree damage nearby. Several softwood trees near the peak damage indicator were shredded and heavily debarked, a double-wide mobile home was destroyed, and more trees were snapped. The tornado weakened to low-end EF3 intensity, flattening a chicken house, with trees and power poles nearby snapping.