From April 2–7, 2025, a slow-moving weather system and a stationary front caused both a widespread and devastating tornado outbreak and historic, life-threatening flash flooding across much of the Southern and Midwestern United States.

The Storm Prediction Center (SPC) began monitoring the Mississippi Valley and surrounding regions on March 28 for the potential of future severe weather, eventually issuing a rare high risk for April 2, just weeks after a historic tornado outbreak in the same general area. Later that day, a tornado struck Owasso, Oklahoma, causing damage to homes. An EF1 tornado struck Nevada, Missouri, removing roofs from homes and injuring at least one person. An EF2 tornado struck Pilot Grove, Missouri, destroying a manufactured home and tossing cars. The tornado sirens in the town did not sound due to a malfunction, though no one was hurt. A large, multiple-vortex EF3 tornado moved through the city of Lake City in Arkansas, prompting a tornado emergency issuance. An indirect fatality occurred after an EF2 tornado struck Advance and Delta in Missouri, leaving significant damage to homes. In the early morning hours of April 3, an EF3 tornado struck Selmer, Tennessee, killing three people within the city and two others in surrounding McNairy County. Another supercell produced another EF3 tornado near Slayden, Mississippi, prompting the issuance of another tornado emergency. Near La Grange, Tennessee, two fatalities occurred when a tornado destroyed a mobile home.

The slow progression of the weather system also resulted in days of heavy rainfall and caused catastrophic flash flooding across much of the Ohio Valley. A broad swath of of rain fell across the same areas, especially in the state of Kentucky. Multiple major rivers overflowed their banks, causing widespread damage in neighboring towns, with some nearing record crest levels. Due to multiple rounds of severe weather hitting the same areas, storm surveys had to be delayed for several days. In total, 24 people died as a result of the system; eight from tornadoes, along with one indirect death, and 15 from non-tornadic activity, including the flooding. Furthermore, at least 47 have been injured. With a total of 157 confirmed tornadoes, the outbreak received a score of 96 on the Outbreak Intensity Score (OIS), classifying it as a "devastating" outbreak. The tornado outbreak and flooding caused a total of $4.1 billion in damage.

Meteorological synopsis April 2–3

Forecast Starting on March 28, 2025, the Storm Prediction Center began monitoring the risk of a severe weather event on April 2. Following a lack of expected severe potential the previous day, strong moisture return and the development of an upper-level system was discussed, with a 15% risk for severe weather being outlined over much of the middle Mississippi and Ohio Valleys. The next day, as forecast models came into greater agreement about the mode and timing of the system, a 30% risk was introduced over parts of Arkansas, Missouri, Mississippi, Tennessee, Illinois, Indiana, and Ohio, with forecasters describing that confidence existed for "a widespread, potentially substantial severe event". On March 30, the forecast was expanded to include parts of Texas, Louisiana, and Michigan in the risk area, as forecasted shear supported a primarily supercell-focused storm mode.

Three days out from the event, on the morning of March 31, an enhanced (3/5) risk was outlined over an area overlapping the previous 30% zone, now also including small parts of Oklahoma, Iowa, and Alabama, while now covering the majority of Kentucky, Illinois, Arkansas, and Indiana. The system, now described as a negatively-tilted trough, was expected to produce a widespread outbreak of severe weather over the region. A large warm sector over the Great Lakes region, a powerful jet streak of , and an intense cold front, were all expected to contribute to the event, with the forecast outlining the risk for significant tornadoes, strong wind, and large hail. A higher risk category for the forecast was discussed over the middle Mississippi Valley, fueled by the threat of "multiple long-lived significant supercells", but was ultimately decided against due to a lack of confidence in how the storm system developed throughout the day.

An outlook on April 1 introduced a moderate (4/5) risk over small parts of Mississippi, Arkansas, Tennessee, Missouri, Kentucky, Illinois, and Indiana, driven by the threat of "significant to intense tornadoes", as outlined in updated model guidance. Due to significantly less uncertainty regarding the development of the storms, the Storm Prediction Center issued a high risk (5/5) convective outlook over southern Illinois, eastern Missouri, western Kentucky and Tennessee, eastern Arkansas, and extreme northwest Mississippi for "multiple EF3+ tornadoes".

A mid-level trough was positioned over the central United States and will move northeastward, while at the surface, a strong surface cyclone will move through the upper Mississippi Valley, accompanied by a jet streak ejection of , while a cold front moves through much of the region. A moist airmass was moving into the Ozarks and middle Mississippi Valley region, which was expected to rapidly destabilize throughout the day while convection along the cold front continued. MLCAPE, a measure of atmospheric instability, was forecast to reach 2,500–3,500 J/kg in the middle Mississippi Valley, while a rapid ejection of the mid-level jet will bring strong ascent into the warm sector, conducive for intense storm development. The initiation of discrete storms was initially expected to occur east of the cold front inside of an unstable airmass, a region expected to – around 4 to 7p.m. CDT – harbor around 400 m2/s2 of storm-relative helicity in the first 3 kilometers of the atmosphere, alongside deep-layer shear of 60knots. These conditions will be conducive to the development of discrete tornadic supercells, the strongest of which were expected to be capable of producing intense (EF3–EF5) tornadoes. Multiple intense tornadoes were forecasted throughout the evening. More supercells, potentially producing tornadoes, were outlined as a risk in the southern Ozarks and lower Ohio River valley.

More supercells, focused on the threat of strong winds exceeding and large hail exceeding were expected to develop in the region extending from Texas through the Great Lakes region, which were expected to develop bowing line segments producing further severe wind gusts as storms develop. Atmospheric recovery across the Red River valley in Texas had the possibility to support further supercells producing large hail after the main event concluded in the region.

Development of storms Linear convection from the previous day persisted after midnight, with embedded supercells within the line posing a threat for tornadic activity due to the strongly sheared and destabilizing atmosphere over parts of Kansas and Missouri. At 2a.m., a surface-based cold front was still present, positioned from central Kansas towards Texas' southern plains, moving southeast. As moisture entered central Oklahoma, fueled by a strong southwesterly jet and steep mid-level lapse rates, the capped environment eroded, which created an environment conducive towards surface convection, including supercells capable of producing large hail and tornadoes. Later on, at 4:30a.m., as the line had migrated further east ahead of the cold front, forecasters noted that the potential for embedded supercells capable of wind, hail, and tornadoes, was increasing over much of Missouri and bordering regions of Kansas, Arkansas, and Oklahoma. Shortly before 7a.m., storms had been moving across Oklahoma, with a storm in the northeastern part of the state attaining a supercellular structure, producing a brief tornado debris signature in the vicinity of Tulsa and Rogers counties. The line of storms moved parallel to the cold front into a region with an atmospheric capping inversion, which reduced the threat of further organization. Over central Missouri, a "somewhat messy storm mode" near the cold front moved towards an area marked by a relatively stable and capped atmosphere, which reduced the risk of severe hazards by 7:17a.m.

Elevated storms had developed over parts of Ohio and Illinois, which produced a minor threat for hail and damaging winds throughout the later morning hours Further south, in northeastern Texas and surrounding areas, storms had begun forming on a pre-frontal confluence in an area with a minor capping inversion and moderate instability levels around 2500 J/kg. As these storms developed, the hazard of hail and strong tornadoes was noted by forecasters, despite the uncertainty of timing and ability to overcome the cap.

April 4 Forecast The day prior to the outbreak, the Storm Prediction Center outlined an Enhanced (3/5) risk over much of Arkansas and bordering regions of Oklahoma, Texas, and Missouri, as a surface cyclone was forecasted to develop over northeastern Texas or southeastern Oklahoma, which moved to the northeast, moving a warm sector into much of Arkansas and into far southern Missouri. Diurnal heating, alongside a growingly unstable atmosphere, strong shear, and forecasted storm-relative helicity values of 400m2/s2 over the region, were forecasted to support supercells, potentially producing strong tornadoes. Elevated convection along a cold front moving over Texas was also forecasted to pose a threat for large hail. A second outlook that day outlined a Moderate (4/5) risk over much of the same regions, with forecasters now outlining MLCAPE instability values between 2500 and 3500 J/kg over a frontal zone, which was expected to develop strong supercells capable of potentially strong tornadoes as the evening progressed. A conditional threat for strong, long-tracked tornadoes was also outlined ahead of the frontal zone. Despite weak forcing ahead of the frontal zone, strong MUCAPE instability values of 3000 to 4000 J/kg were forecasted to be conducive to the threat of discrete supercell development and the hazard of intense to violent tornadoes.

Confirmed tornadoes

Bay–Lake City–Monette, Arkansas

This large and destructive multi-vortex EF3 tornado developed west of Trumann at 6:26 p.m. CDT. It tracked northeastward across AR 69, causing minor damage to an outbuilding and damaging trees at EF0-EF1 intensity. After crossing I-555, the tornado intensified and fluctuated between EF1 and low-end EF2 strength as it passed southeast of Bay. Power poles were snapped along AR 463 and two freight trains on the BNSF Thayer South Subdivision were derailed. After snapping additional power poles and trees and destroying outbuildings along AR 158, the growing tornado strengthened further as it continued northeastward away from Bay, collapsing or heavily damaging several high-tension power line trusses at EF3 intensity. Shortly after that, at 6:40 p.m. CDT, the National Weather Service in Memphis, Tennessee issued a tornado emergency for Lake City and points northeast. The still-growing tornado then snapped trees and caused major roof and exterior wall damage to homes at EF2 intensity before crossing AR 158 and striking the west side of Lake City at the US 78/AR 158/AR 18/AR 135 intersection at high-end EF3 intensity. Multiple homes had all of their exterior walls and almost all of their interior walls knocked down, and trees were stubbed with some debarking noted, which was thought to be enhanced by flying debris. Northeast of Lake City, the tornado snapped more trees and additional power poles at EF2 strength. One small area of trees was stubbed with this damage being rated low-end EF3.