On March 24, 2023, a severe weather and tornado outbreak began across portions of the lower Mississippi River Valley in the United States. A slow-moving trough moved eastward across the United States and interacted with a moist and unstable airmass originating from the Gulf of Mexico, resulting in widespread heavy rainfall, severe thunderstorms, and significant tornadoes over a four-day period. A violent, high-end EF4 tornado moved through the towns of Rolling Fork, Midnight, and Silver City in western Mississippi, causing catastrophic damage and many fatalities. Multiple tornado emergencies were issued for that tornado and two subsequent EF3 tornadoes from the same supercell that struck Winona and Amory.
Severe weather and tornadic activity continued into the early morning hours of March 25, as a squall line of severe storms with embedded circulations moved eastward across Tennessee and Alabama. A low-end EF2 tornado within the line killed a person in the northern part of Hartselle, Alabama. The slow-moving storm system then stalled the following day, producing more severe weather and tornadoes across portions of Alabama and Georgia from March 26 to March 27, including a couple of strong tornadoes. The outbreak also resulted in numerous reports of damaging straight-line winds, hail, and flooding.
Meteorological synopsis March 24–25
On March 18, the Storm Prediction Center (SPC) first indicated the potential for organized severe weather across the Southern Plains in advance of an upper-level trough across the Western United States. Additional risk areas were issued to the east in later outlooks, concurrent with the eastward-moving trough. By March 23, a level 2/Slight risk was hoisted from Texas northeastward into Missouri, primarily for the threat of large hail. Scattered reports of large hail and damaging wind gusts were received from Texas across into the Mid-Atlantic states. In addition, two EF1 tornadoes occurred in Parker County, Texas, during the early morning hours of March 24.
Farther to the east across the lower Mississippi River Valley, a more substantial threat for severe weather unfolded. On March 22, the SPC issued a level 3/Enhanced risk of severe weather across portions of Louisiana, Arkansas, and Mississippi, for supercell thunderstorms capable of large hail, damaging winds, and strong (EF2+) tornadoes. The Enhanced risk was expanded northward the following day, and the original outlined area was upgraded to a level 4/Moderate risk. On the morning of March 24, water vapor imagery depicted a potent mid-level trough over northern portions of the Baja California peninsula. The trough was expected to move quickly eastward, accompanied by strong mid-level winds between the trough and strong high-pressure area across the Southeastern United States. Meanwhile, a rapidly deepening low-pressure area was expected to drag a warm front northward, leading to a broad, unstable air mass to its south. Although some reduction in moisture was expected across Mississippi due to drier air aloft and warm surface temperatures into the 80s °F, continued advection of moist air from the Gulf of Mexico seemed supportive of dewpoints in the upper 60's and lower 70's across Louisiana, Arkansas, and Mississippi by the evening hours. Thus, mixed-layer convective available potential energy was expected to rise into the 1,500–2,000 J/kg range. Initial forecaster thinking was that strong forcing for ascent across Arkansas would lead to an organized squall line capable of both tornadoes and damaging winds, whereas more discrete supercells would be possible farther south, particularly along north–south oriented confluence bands in the open warm sector. A tornado watch was issued shortly thereafter at 5:15 p.m. CDT for portions of eastern Arkansas, northeastern Louisiana, central and northern Mississippi, and western Tennessee. The watch mentioned the possibility of several strong to intense tornadoes with any persistent supercells.
Clusters of storms evolved along these bands in conjunction with improving wind shear profiles. However, given their displacement from the surface low and better forcing, there was some uncertainty as to whether they would become better organized. A strengthening low-level jet and surface moisture increased confidence in the maturation of these cells, but tornadic development had not yet begun in the area as of 0000 UTC. At their 0100 UTC outlook, the SPC lowered the probability of tornadoes to a 10% hatched tornado area, thus downgrading the moderate risk to an enhanced risk, citing that instability in the area was weaker than expected and that there was increased confidence in only limited buoyancy developing. However, as the update was being issued, a significant supercell evolved across western Mississippi, producing a violent, long-tracked, and deadly high-end EF4 tornado that struck Rolling Fork, Midnight, and Silver City, inflicting catastrophic damage, and causing over a dozen fatalities. Although this supercell became embedded within a line segment, it soon produced another deadly tornado of EF3 strength that impacted Black Hawk and Winona, followed by another deadly EF3 tornado that struck New Wren and Amory. To the north, an organized line of convection with embedded supercells moved across Tennessee and Alabama, and although its strength was inhibited by lower moisture and a lack of robust instability, it still produced damaging winds and several additional tornadoes into the early morning hours of March 25, including a low-end EF2 tornado that caused a fatality in the northern part of Hartselle, Alabama. A few lingering severe storms continued into the afternoon hours, resulting in two more weak EF0 tornadoes that occurred in southern Alabama and Georgia.
March 26–27 After the weather system responsible for the outbreak became stalled within the atmospheric region centered around central Mississippi and Alabama throughout March 25, the focus shifted to a new corridor for severe weather potential setting up across many of the same areas on March 26. In this corridor, which extended from Louisiana into western Georgia, CAPE values reaching into the 1500–2000 J/kg range, effective 50-knot wind shear, and elevated dew points were present, allowing for a favorable environment for the re-intensification of the system, and its segmentation into individual supercells. As such, the SPC issued a 4/5 moderate risk for this corridor at their 1630 UTC outlook, driven by both a 15%, hatched contour for strong (EF2+) tornadoes for the strongest cells and a 45%, hatched contour for very large (2+ inch diameter) hail. A 30% risk of damaging winds was specified in this outlook. On the morning of March 26, supercells quickly developed, one of which produced an EF3 tornado that caused major damage in North West Point, Georgia. Additional significant tornadoes were expected to occur across portions of the threat area farther west, though mostly isolated weak tornadoes occurred. One EF2 tornado caused significant tree damage as it passed near Catherine, Alabama. However, these storms did produce widespread large to very large hail up to the size of baseballs () along with dozens of damaging wind reports. A few additional isolated supercells continued into the early morning hours of March 27, one of which produced an EF2 tornado that struck Milstead, Alabama. A couple of additional weak tornadoes touched down before the outbreak came to an end.
Confirmed tornadoes
March 24 event