A significant tornado outbreak, along with a derecho, affected much of the Midwestern and Southeastern United States from April 1 to 3, 2024. The National Weather Service issued dozens of severe thunderstorm and tornado warnings across those regions during the event. The outbreak first began over portions of the Great Plains and Midwest on April 1, with widespread large hail and damaging winds and a few tornadoes being reported. The outbreak then spread to the Midwest and Ohio Valley on April 2, where the derecho occurred. This was followed by supercell development later in the afternoon. Severe storms also affected parts of the Mid-Atlantic on April 3 as well. A total of 32 million people were estimated to be under watches or warnings, and over 700,000 people were estimated to be without power. Twenty-five people were injured; and five people were killed, all of them by non-tornadic events; three of which happened when downed trees fell onto vehicles in Pennsylvania and New York. The storm system was also responsible for causing flooding in parts of the Northeast, and heavy snow over parts of the Midwest and Northern New England.
The Storm Prediction Center first outlined on April 1 an enhanced risk in areas from north Texas to eastern Illinois, encompassing much of the central United States. In the afternoon hours of the same day, supercell thunderstorms began to develop across northern Texas, moving northeastward and producing large hail. As the event progressed, many tornadic supercells produced brief and weak tornadoes along with high wind gusts; a gust of was recorded in West Virginia, classifying the squall line as a derecho.
The National Weather Service declared the tornado outbreak "historic", stating that not only did it set a daily record for West Virginia, but also broke the yearly record, in one day. Ten tornadoes occurred in West Virginia; which also set a state record for the most tornadoes confirmed in a single day. The previous record was seven; set on both April 4, 1974 and June 2, 1998.
The outbreak was the largest of 2024 prior to the tornado outbreak of April 25–28. In all, 86 tornadoes touched down in total, the highest of which were 14 EF2-rated tornadoes confirmed during the event.
Meteorological history
On March 28, the Storm Prediction Center (SPC) first delineated a risk of organized severe weather across the Central and Southern Plains, as well as the Mississippi and Ohio River valleys for the beginning of April. By the morning of April 1, a broad Enhanced Risk spanned from north-central Texas northeastward toward the Illinois–Indiana border, where widespread supercell thunderstorms were anticipated. The impetus for the severe weather setup came as a large, positively tilted upper-level trough progressed eastward from the Southwestern United States into the Central Plains region. Morning surface observations revealed an area of low pressure over central Kansas, supporting a north-moving warm front to the east into Ohio and a trailing cold front southwestward into Oklahoma and the Texas Panhandle. Meanwhile, an eastward-shifting dry line resided from the Texas Panhandle southward into northern Mexico. Within the warm sector of this low, an unstable environment was expected to develop, with averaged instability values of 2,000–3,000 J/kg, dewpoints in the mid- to upper-60s °F, very strong wind shear throughout the atmosphere, and rapidly cooling temperatures with height. Given these conditions, the SPC upgraded much of the eastern half of Oklahoma and a small section of northern Texas to a Moderate Risk. In this area, the capping inversion aloft was expected to erode throughout the afternoon, giving way to multiple supercells capable of producing large hail in excess of . A conditional threat of strong/EF2+ tornadoes was also noted as wind shear close to the surface strengthened with time.
Through the afternoon hours, semi-discrete supercells developed across north and central Texas, contributing to widespread reports of large hail the size of baseballs, in addition to hurricane-force wind gusts upwards of . Further to the northeast, isolated severe weather occurred in Oklahoma, though it was curtailed by persistent cloud cover and a broad rain shield across the risk area. Even farther to the northeast, training supercell thunderstorms tracked across the St. Louis metropolitan area, producing large hail. By the evening hours, a quasi-linear convective system developed across eastern Oklahoma and progressed toward Missouri and Illinois. In spite of modest instability, strong vertical wind shear maintained organized convective activity as it spread eastward from southern Illinois and eventually into West Virginia during the pre-dawn and early morning hours.
Numerous reports of damaging winds were received, including gusts in excess of near Huntington, West Virginia. The squall line posthumously met the criteria of a derecho, and post-storm surveys revealed dozens of tornadoes along its track. In particular, 10 tornadoes were confirmed across West Virginia on April 2, the most observed in a single calendar day on record. Convective activity finally lost vigor as it moved toward the West Virginia–Virginia border into a more stable environment.
As the derecho tracked from Missouri to West Virginia early on April 2, another widespread outbreak of severe weather and tornadoes was expected to occur across the broader Ohio River Valley region. On April 1, the SPC issued a Moderate risk across much of Ohio and adjacent portions of surrounding states, that outlook was valid for April 2. Despite questions about the influence of widespread morning thunderstorms, forecasters felt there was sufficient confidence that the atmosphere would recover over subsequent hours, contributing to discrete or clusters of storms capable of producing damaging winds, large hail, and multiple significant tornadoes.
By the afternoon hours of April 2, forecasters expressed concern that morning convection would stunt the degree of destabilization across portions of the risk area, particularly in Ohio. Farther to the west, an environment characterized by surface temperatures of in the low- to mid-70s °F, dewpoints between , and strong vertical wind shear was still expected to promote a substantiative risk for strong tornadoes. Storms across southern Indiana and western Kentucky initially struggled to intensify during the afternoon, but they eventually matured into tornado-producing supercells as they continued eastward into western Ohio. As convective activity to the north continued eastward into a drier and more stable environment, a cluster of storms developed farther south across Alabama and Georgia, which contributed to additional tornadoes. Additional severe weather occurred along frontal boundaries across several states from Florida to Virginia on April 3 before activity behind offshore.
Confirmed tornadoes
April 1 event + List of confirmed tornadoes – Monday, April 1, 2024EF#LocationCounty / parishStateStart Coord.Time (UTC)Path lengthMax width EF0ChesterfieldSt. LouisMO23:32–23:35A high-end EF0 tornado caused minor roof and siding damage to homes, blew down part of a fence, and damaged trees, including some that were snapped or uprooted. EF1N of Hominy to SE of WynonaOsageOK00:17–00:27This high-end EF1 tornado snapped or uprooted numerous trees and blew down numerous power poles. EF1ESE of Wynona to W of BarnsdallOsageOK00:28–00:36A large, high-end EF1 tornado formed almost immediately after the previous tornado dissipated. It blew the roof off of a garage, uprooted or snapped trees, and blew down numerous power poles. EF1Southeastern BarnsdallOsageOK00:38–00:41Homes were damaged, outbuildings were destroyed, and trees and power poles were blown down. An even stronger tornado would strike this area a month later. EF1N of OchelataOsage, WashingtonOK00:49–00:56A tornado damaged outbuildings, uprooted trees, and blew down power poles. EF1N of DelawareNowataOK01:13–01:19Trees were uprooted, large tree limbs were snapped, outbuildings were damaged, and power poles were blown down. EF1WNW of Fair GroveGreeneMO03:37–03:44Several trees were uprooted or snapped, an outbuilding was heavily damaged, and a residence suffered minor damage. EF0NE of Long LaneDallas, LacledeMO04:06–04:14A tornado uprooted and/or snapped over 200 trees, rolled an unanchored mobile home, damaged the roof of a residence, and damaged multiple outbuildings. EF0MorganLacledeMO04:20–04:27An intermittent tornado damaged outbuildings and trees, including some trees that were snapped or uprooted. EF0NNE of EvergreenLacledeMO04:24–04:30Some outbuildings and trees were damaged by an intermittent tornado.
April 2 event