From May 19–22, 2024, a major and widespread tornado outbreak took place across the Central United States, High Plains and the Upper Midwest. On May 19, severe weather produced destructive hurricane-force straight-line winds, very large hail, and numerous tornadoes across mainly Kansas and Oklahoma. One large EF2 tornado prompted the issuance of a tornado emergency for Custer City, Oklahoma while another EF2 tornado passed near Yukon.
On May 21, the Storm Prediction Center issued a Moderate risk for severe weather in the states of Iowa, Missouri, Minnesota, Wisconsin, and Illinois, including a 15% hatched risk for significant, long-track tornadoes. As a result, a Particularly Dangerous Situation tornado watch was issued. A few tornadoes occurred near Macedonia and Red Oak. One long-tracked and violent tornado touched down near Villisca, Iowa. Continuing northeast, it toppled and crumpled several wind turbines. The tornado then approached Greenfield, where it intensified to EF4 intensity. Numerous homes were damaged or destroyed with some of them being reduced to their foundations or swept clean. Vehicles sustained severe damage as well and multiple trees were severely debarked. Four people were killed in Greenfield. Another fatality occurred near the town of Corning, about 30 miles southwest of Greenfield when the tornado blew a vehicle off the road. At least 35 people sustained injuries to some degree. A Doppler on Wheels measured winds in a small area between above the surface near Greenfield making this one of the highest windspeeds ever recorded in a tornado.
Five people in total died as a result of this outbreak, all of which came from the Greenfield tornado, while 69 people were injured from tornadic activity on both May 21 and 22, with total damages at just under $5 billion. With a total of 81 confirmed tornadoes, this outbreak was the second during a very active May, following a tornado outbreak from May 6–10, and just days before another large outbreak occurred from May 25–27.
Meteorological synopsis May 19
On May 19, the Storm Prediction Center (SPC) outlined a moderate risk of severe weather across southwest to central Kansas, encompassed by a enhanced risk that extended into northwestern Oklahoma as well. Across the highest risk area, forecasters warned of the potential for a developing derecho capable of producing damaging winds upwards of . By the early afternoon hours, a northwest-to-southeast-oriented dryline extended from eastern Colorado into the Texas Panhandle, while a cold front laid across northern and central Kansas. Between these boundaries, dewpoints rose into the lower 60s °F and effective wind shear reached , supportive of supercell thunderstorms that would likely evolve into a line of storms as a shortwave trough approached from the west. Given the environment, the SPC issued a particularly dangerous situation severe thunderstorm watch across much of Kansas, northwestern Oklahoma, and the far northeastern Texas Panhandle. An intense supercell in Custer County, Oklahoma, formed an intense multi-vortex tornado near Custer City, resulting in a tornado emergency. This tornado was accompanied by an intense rear-flank downdraft surge, with the total damage path width being recorded at . A Ka-POL radar from Texas Tech University had been recording the tornado throughout its life cycle, and recorded a wind gust of near the surface, while confirming the tornado's actual width of . An intense supercell developed in north-central Kansas, producing large hail in excess of , tornadoes, and a wind gust to near Russell, eventually growing upscale as additional convective clusters formed to the southwest. In Oklahoma, an isolated intense supercell developed and tracked eastward toward the Oklahoma City metropolitan area as low-level wind shear began to increase. Meanwhile, dual mesoscale convective vortices tracked across eastern Kansas, contributing to widespread damaging wind reports—including multiple high wind gusts in excess of —as well as several tornadoes. As the complexes continued into Missouri, they encountered more stable air, causing the severe threat to gradually diminish.
May 20–21
The severe threat shifted northward on May 20 as the SPC issued an enhanced risk across northeastern Colorado and southwestern Nebraska. Here, forecasters expected a mixture of supercells and clusters of storms to originate near the Palmer Divide. Although rich moisture waned with westward extent, dewpoints in the upper 50s to lower 60s °F were expected to spread northwestward from Kansas and into Colorado. Thunderstorms developed in this area by the late afternoon hours, though their growth was stunted by marginal instability. Several discrete supercells eventually evolved across northeastern Colorado and began to grow upscale while encountering a more moist and unstable environment to the east across western Nebraska. The bowing line of storms traversed Nebraska and eventually Iowa through the pre-dawn and early morning hours of May 21, resulting in continued damaging wind gusts.
On May 21, the SPC issued another moderate risk for severe weather in the states of Iowa, Missouri, Minnesota, Wisconsin, and Illinois, including a 15% risk for significant tornadoes. Upper-air soundings observed steep lapse rates in the middle troposphere over parts of Kansas and Missouri on the morning of May 21. The SPC predicted that these conditions would spread into the primary severe weather risk area, overlapping with a moist airmass with dew points approaching and leading to strong potential atmospheric instability. That morning, an organized cluster of thunderstorms moved into Iowa after having produced severe wind gusts in central and eastern Nebraska. This line of storms continued across central and eastern Iowa just north of a warm front, presenting a continued threat for damaging wind gusts. Additional storms began to develop along the border between Kansas and Nebraska ahead of an approaching trough. The SPC anticipated that the atmospheric environment over eastern Nebraska and western Iowa would become increasingly conducive for further organization of these storms into supercells. A tornado watch was issued by the SPC for areas near and along the Nebraska–Iowa border region at 11:10 a.m. CDT in anticipation of these changes. At 1:10 p.m. CDT, the SPC issued a tornado watch flagged as a particularly dangerous situation for much of Iowa and parts of surrounding states, including an 80% likelihood of a significant tornado occurring within the watch area. Supercells were active over southwestern Iowa by the mid-afternoon, approaching an environment favorable for tornadogenesis leading into the Des Moines area.
Multiple tornadoes were reported in Iowa, including a damaging tornado near Corning and in Greenfield, where multiple fatalities were reported. Tornadoes were also reported in Minnesota and Wisconsin.
May 22
On May 22, the SPC outlined an enhanced risk extending from central Texas across southeastern Oklahoma, extreme northwestern Louisiana, and southwestern Arkansas. In Texas, a cold front stretched from the Red River southwestward into the Permian Basin, with a surface trough just ahead of that front. Supercells were expected to evolve within a sheared and deeply unstable environment given effective wind shear of and mixed-layer CAPE of 3,000 J/kg. As such, very large hail was anticipated to be the main threat, although isolated tornadoes were possible too before storms grew upscale into one or more convective lines. To the northeast, lines of storms tracked across Oklahoma, Arkansas, and Tennessee, with a primary risk of damaging winds and large hail. Meanwhile, intense supercells developed across central Texas in a very unstable and deeply sheared environment, riding along outflow boundaries that enhanced the tornado threat. A particularly intense EF3 tornado developed southwest of Sterling City where rocks, grass, and topsoil were stripped off of the ground. A wide path of trees were debarked and sandblasted, with only trunks remaining in some cases. Caliche roads were also stripped. Ongoing storms across Texas eventually evolved into an intense mesoscale convective system moving across eastern portions of the state and into Louisiana through the late evening.
Confirmed tornadoes
Villisca–Carbon–Washington, Iowa
This large, long-tracked and intense tornado first touched down near Nyman, Iowa at 2:43 p.m. CDT along 130th Street, initially causing EF0 damage before snapping several trunks from hardwood trees near K Avenue at EF1 intensity. The tornado damaged several houses and uprooted several trees before strengthening to high-end EF2 intensity near the intersection of 240th Street and T Avenue, where the majority of the roof of a house was removed. Crossing U.S. Route 71 and then U.S. Route 34, it weakened as the tornado continued to snap trees and destroying a barn at high-end EF1 intensity near the Hacklebarney Woods in the outskirts of Villisca. Numerous other outposts were damaged or had their roofs collapsed in as well. Restrengthening to EF2, the tornado then struck numerous households on 200th Street, where the majority of the roof of one was removed, while the column anchorage of another ended up failing, destroying most of the house.
The tornado continued to maintain EF2 intensity as it destroyed another barn nearby on Aspen Avenue, before traveling over mostly open terrain and doing little damage and possibly weakening. Approaching 175th Street, the tornado quickly strengthened to its peak intensity at mid-range EF3 intensity, collapsing the walls of a house and leaving only a few rooms standing. It weakened slightly as it crossed 170th Avenue and collapsing the exterior walls of two houses at high-end EF2 strength, before causing EF3 damage again as it collapsed the walls of several more on 150th Avenue. Little damage occurred after as it tracked over more open terrain, causing only EF0 damage at a barn on the edge of its circulation, where a door was collapsed. At this point the tornado turned slightly more to the east, snapping a power pole on 130th Street at EF2 strength. Passing just north of Washington, Iowa, the tornado caused sporadic EF1 and EF2 damage before weakening and lifting at 3:21 p.m. CDT just south of the Adams County border.
Remarkably, no fatalities or injuries occurred from this tornado, which was likely due to it passing over mostly rural regions. With winds of , the tornado was on the ground for 38 minutes and tracked , and was at its peak width. Additionally, it was on the ground simultaneously with the Greenfield EF4 tornado to its south for about two-thirds of its path.
Nodaway–Corning–Greenfield, Iowa