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 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 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. 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 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, 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 (2.75 in (7.0 cm)) along with dozens of damaging wind reports. A few additional isolated supercells continued into the early morning 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
Rolling Fork–Midnight–Silver City, Mississippi
This violent, deadly high-end EF4 tornado first touched down in Issaquena County southeast of Mayersville near the Mississippi River. It tracked northeastward over the Steele Bayou Canal and into Sharkey County, producing EF0 to EF1 damage to trees, power poles, and some outbuildings. The tornado then rapidly grew in size and reached EF2 strength as it approached Rolling Fork from the southwest, prompting the issuance of two tornado emergencies. The tornado then became violent and reached EF4 intensity as it entered Rolling Fork, producing catastrophic damage throughout much of the town. Frame homes and duplexes were completely leveled or swept from their foundations, approximately 30 manufactured homes were obliterated, and copious amounts of structural debris was scattered throughout the community. Several structures at an agriculture business, were completely flattened, the local library was completely destroyed, the Rolling Fork Police Department was nearly destroyed, while the fire station, post office, city hall, Rolling Fork Elementary School, South Delta High School were significantly damaged. Multiple older brick buildings in downtown Rolling Fork also had major structural damage, with some well-built businesses and structures completely leveled with only piles of debris remaining. One of the town's water towers was toppled when flying debris compromised its base, leaving a crater where it impacted the ground. Some of the most violent damage occurred in the northeastern part of town, where a flower shop housed in a well-built brick building was completely leveled at high-end EF4 strength, with its concrete foundation slab being partially swept clean of debris. The survey team also noted that the tornado may have reached EF5 intensity here based on the damage to the shop, but the neighboring building was only leveled and not swept away, so there was not enough confidence in upgrading the tornado to EF5. Several nearby homes were also obliterated and large metal-framed buildings, including a Family Dollar store, were completely flattened as well. Many vehicles were also thrown through the air and mangled, and numerous large trees in and around Rolling Fork were denuded and debarked, and a few of them were completely stripped clean of all bark.
After exiting Rolling Fork, the tornado remained violent as it moved across several open fields, where severe ground scouring occurred and debris from the town was scattered long distances to the northeast. Several utility poles were snapped off at the base or pulled out of the ground, and some were left covered in up to 1–2 in (2.5–5.1 cm) of mud. A few of the missing power poles were never found. Southeast of Anguilla, the tornado inflicted EF4-strength damage again to hardwood trees, with most completely mangled or debarked. A mobile home was swept away and obliterated with very little debris remaining, and a bus on the property was tossed into trees. Aerial imagery of this area also revealed ground scouring and the presence of cycloidal marks in open fields. Beyond this point, the tornado caused widespread EF2 tree damage in wooded areas. It also destroyed a small frame home and a mobile home before regaining low-end EF3 intensity and mowing down large swaths of trees.
Maintaining low-end EF3 strength, the tornado then crossed into Humphreys County. The tornado briefly strengthened to high-end EF3 strength as it completely leveled a small brick home, and overturned a nearby grain loader. Grain bins were heavily damaged in this area as well, debris was scattered for hundreds of yards into a field, and a grain cart was thrown into the field as well. Passing through the small community of Midnight, the tornado produced EF2 damage as a home, a brick building sustained damage and trees and power poles were snapped. The tornado then moved northeast as it approached Silver City from the southwest. A mobile home was completely destroyed after being thrown 75 ft (23 m) into a nearby field, with only the porch being left behind. A portion of the roof was blown off a school, and two metal buildings were destroyed with large support beams bent and debris scattered across fields. Large areas of hardwood trees were snapped and uprooted.
The tornado then weakened some but continued causing significant damage as it moved into Silver City, where multiple apartment buildings suffered heavy roof damage, including some that had portions of their roofs removed and one that had its walls partially collapsed. Many homes throughout the town had extensive roof damage, some were completely unroofed, and a few sustained collapse of one or more exterior walls. Four manufactured homes were completely destroyed in the center of town, a church sustained roof damage, a large number of old hardwood trees were also snapped or uprooted, and power lines were downed as well. Damage in Silver City was rated EF1 to EF2 in intensity. After passing through Silver City, the tornado weakened and dissipated while causing EF1 to EF0 damage. In total, it traveled 59.4 miles (95.6 km) at an average forward speed of 50.19 mph (80.77 km/h), killing 17 people and injuring 165 others.