From March 14 to 16, 2025, a widespread and deadly tornado outbreak, the largest on record for the month of March, affected much of the Midwestern into the Eastern United States, with additional severe weather and impacts on the East Coast. The Storm Prediction Center (SPC) first issued a moderate risk for severe weather for parts of the Midwest and Southeast on March 14 as a large upper-level trough moved east over the Rockies. The Day 2 outlook was upgraded to a tornado-driven high risk area for portions of Mississippi and Alabama, making it the third ever issuance of a Day 2 high risk, with the previous two being for April 7, 2006 and April 14, 2012.
On March 14, a moderate risk for severe weather was issued for the much of Iowa, Illinois, and Missouri, with a 15 percent risk for significant tornadoes centered around Southern Illinois and Southeastern Missouri. In the early evening, a PDS tornado watch was issued for portions of Southeast Missouri, Northeast Arkansas, Northern Mississippi, and more. Among the tornadoes that touched down that day were an EF3 tornado that killed three people in Bakersfield, Missouri, a long-track, high-end EF3 tornado that tracked through southern Missouri and prompted the issuance of a tornado emergency for Fremont and Van Buren, an EF2 tornado that moved into the Greater St. Louis area, notably crossing a St. Louis Lambert International Airport runway while a plane was taking off, a very long-track, low-end EF4 tornado that struck near Fifty-Six and rural areas of Izard County, Arkansas, a high-end EF4 tornado that caused catastrophic damage to a farm and rural neighborhood near and in Diaz, Arkansas, a long-track, high-end EF3 tornado that went through Cushman and Cave City, Arkansas, killing three, and a low-end EF3 tornado that killed one person after ripping through a trailer park near Poplar Bluff, Missouri. Due to the outbreak occurring on Pi Day, the National Weather Service (NWS) referred to this part of the outbreak as the Pi-Day tornado outbreak.
On March 15, the SPC continued the high risk area, delineating the potential for a widespread outbreak to occur with long-track and potentially violent tornadoes expected, with Particularly Dangerous Situation (PDS) tornado watches being issued for the respective regions. In the early afternoon, a tornado emergency was issued for parts of Walthall, Lawrence, Marion, and Jefferson Davis counties in Mississippi as a large, violent, long-track EF4 tornado was moving through the area; six people were killed and 14 others were injured by this tornado. Tornadoes continued in Mississippi and Alabama throughout the afternoon and evening, including an EF2 tornado that struck Winterboro, Alabama, damaging a high school and killing one person, and an EF3 that killed two people near Plantersville, Alabama. On March 16, a slight risk for tornadoes was issued for the South Atlantic States as several weak tornadoes touched down across the East Coast.
At least 44 people were killed by tornadoes and other weather-related impacts across eight states. Additional non-tornadic impacts associated with the system involved damaging straight-line winds that fueled wildfires in Oklahoma and a dust storm in some areas as a result further east near the Upper Midwest. With a total of 118 confirmed tornadoes, the outbreak became the largest ever in the month of March, and received a score of 147 on the Outbreak Intensity Score (OIS), making it the highest ranked tornado outbreak of the decade and overall classifying it as a "historic" outbreak. The outbreak caused $11 billion in damages, making it the costliest tornado outbreak in United States history when unadjusted for inflation.
Meteorological synopsis Background As early as March 7, 2025, the Storm Prediction Center (SPC) began monitoring the threat of severe weather posed by a vigorous large-scale trough ejection over the High Plains and Upper Midwest. At that point, the large spread in possible outcomes represented in numerical weather prediction computer models prevented the SPC from designating a specific area at risk. By March 9, a 15% severe risk area was introduced for March 14 over the Mississippi Valley and for March 15 over the South. These areas were both upgraded to a 30% risk for severe weather on March 10, as multiple forecast models began to come into agreement on an all-hazards threat (of wind, hail, and tornadoes), including a supercell-focused mode potentially evolving into a QLCS threat. An outlook on March 11 described the March 14 system as "anomalously intense upper cyclone", with a second upper-level trough expected to produce severe weather on March 15.
On March 13, the SPC upgraded the risk for March 14 into a moderate (4/5) risk over parts of the Middle Mississippi valley, including much of Illinois and Missouri, alongside small parts of Iowa, Kentucky, Arkansas, and Tennessee. This risk was described as a "regional outbreak of severe storms", driven by the risk of storms producing swaths of damaging winds potentially in excess of over the region, with areas further south expected to be conducive to the development of strong tornadoes later in the day. The outlook for March 15 was also upgraded to a moderate (4/5) risk as an environment more conducive for significant tornadoes as favorable wind profiles alongside moderate instability produced the conditions necessary for "robust updrafts and intense supercells". A conditional risk was also highlighted further north into Ohio and Kentucky, which were expected to face a primarily non-severe event, reliant on the intensity of convection further south that could stabilize the atmosphere. That same day, as the system moved through the West Coast, it spawned a high-end EF0 tornado in the Los Angeles area, though this is not considered part of the outbreak.
At the 1730Z Day 2 outlook on March 14, a high (5/5) risk was introduced over parts of Mississippi and Alabama, driven by the risk of a tornado outbreak. This was just the third time that the Storm Prediction Center issued a high risk for its Day 2 outlook since 2006, the other two occurring on April 7, 2006 and April 14, 2012.
March 14
The states of Iowa, Missouri, Illinois, Kentucky, Tennessee, Arkansas, and Mississippi were under a moderate risk for severe weather, as an unusually strong negatively tilted upper-level shortwave trough detected on satellite that morning was expected to produce an intense mid-level jet that followed its parent shortwave and move towards the center of the continental United States. These features produced strong ascent, which, alongside a powerful surface cyclone expected to form and move from the central High Plains towards the Upper Midwest, produced the conditions necessary for the development of significant severe weather. Over much of the middle Mississippi Valley, strong diurnal heating was expected to occur, which, alongside a low-level jet to aid boundary-level moisture, allowed for the development of surface-based storms, which were expected to produce a single fast-moving band of convection that was expected to produce gusts up to over the region.
Further to the southeast over Missouri, forecasters outlined the risk of more discrete thunderstorms developing on the northern edge of a more concentrated area of low-level moisture. These storms were expected to form into at least semi-discrete supercells due to the presence of strong upper-level flow and strong deep-layer shear. The HRRR model suggested that widespread supercells could develop late in the afternoon, potentially as far south as the border of Mississippi, Arkansas, and Tennessee, with soundings of other forecast models, including the NAM model, favoring the development of intense supercells capable of producing large hail of and potentially significant or intense tornadoes.
Throughout the lower Mississippi Valley, lesser forcing was expected to preclude any possibility of widespread severe weather, but forecasters noted that the atmosphere were capable of producing supercells, some of which had the hazard for large hail, damaging winds, or tornadoes, for any supercells that sustain themselves.
The first complex of storms had emerged by 10:25a.m. Central Daylight Time (UTC–5) over southern Kansas and northeastern Oklahoma, which moved into a region of high atmospheric stability and strong convective inhibition, with a minimal severe hazard risk expected to be limited to small hail up to . The Storm Prediction Center was expecting the formation of an intense squall line to initiate between 3 and 5p.m. that afternoon. In the evening, a PDS tornado watch was issued for an area in the Mississippi Valley, with severe thunderstorms expected to develop in conditions primed for supercells capable of producing strong, long-track tornadoes. As forecast, numerous supercells began developing across the main risk area, and numerous tornadoes occurred, some of which were long-tracked, and strong to violent.
March 15
A large warm sector had developed over much of the Gulf Coast states, producing widespread dew points near . That morning, storms had begun developing across the northern edge of the area of elevated moisture. Temperatures to the south and east of these storms were expected to rise to , with multiple bands of convection expected to initiate between 12 and 2p.m. CDT. Moderate levels of CAPE-based instability, ranging from 1500 to 2500 J/kg, and elongated hodographs, forecasted to produce 400–500 m2/s2 storm-relative helicity in the first kilometer of the atmosphere, was expected to "favor the rapid development of intense supercells", and alongside strong Significant Tornado Parameter (STP) values of 5–10, were expected to produce numerous tornadoes, some of which may be long-track or violent, as the day progressed.
Further north, across northern Alabama and south central Tennessee, the consolidation of storms was expected to bound stronger tornadoes to an area further south, with the northern structure highlighted as a potential area for bowing segments and embedded supercells, prompting the SPC to highlight an area of higher wind risk over these areas. Across parts of Georgia and western South and North Carolina, a weakly unstable air mass alongside intense mid-level flow was expected to produce an environment capable of supporting supercell and line structures, with a risk highlighted for severe wind and tornadoes in the region. Storms from the previous day over the Ohio Valley was expected to continue east as the day progressed, producing a risk for hail and wind, but as the day progressed, forecasters noted the uncertainty of potential airmass recovery that could be conducive for a severe risk over Indiana and southern Michigan later that evening, with models only showing weak instability below 500 J/kg that morning. Soundings from Louisiana and Mississippi indicated that the warm sector included steep lapse rates of 7–8 degrees Celsius from the 700–500 millibar (3,013–5,576 m, 9,882–18,289 ft) layer. A jet at 250 millibars (10,366 m, 33,999 ft) was expected to strengthen the region's wind profile, which, in conjunction with a lower-level jet moving east throughout the day, produced an environment capable of all hazards, including the threat of strong tornadoes.
The high risk area continued into the Day 1 Outlook, including a 30% "hatched" risk for significant tornadoes in central Mississippi and Alabama. In the late morning, a PDS tornado watch was issued for parts of Louisiana and nearly all of Mississippi and later much of Alabama as a tornado outbreak featuring "significant tornadoes, some of which should be long-track and potentially violent," was expected throughout the afternoon and evening.
Confirmed tornadoes
Gamaliel, Arkansas/Bakersfield–Frankville, Missouri