Outbreak of tornadoes and severe weather in the United States
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A significant tornado outbreak sequence took place from March 24–28, 2021 in the Southern United States, just one week after another outbreak affected similar regions. There were 43 tornadoes confirmed across 11 states, with the bulk of activity primarily on March 25, which resulted in the Storm Prediction Center (SPC) issuing its second high-risk outlook for the month of March, as well as the second high-risk outlook for 2021. Several intense tornadoes touched down on that day, including ones that prompted the issuance of rare tornado emergencies near Hoover, Alabama, Brent and Centreville, Alabama, and in the Newnan, Georgia area. March 27 also saw widespread tornado activity mainly across East Texas, Southern Arkansas, Louisiana, and Western Tennessee with several strong tornadoes touching down. Scattered to widespread wind and hail damage occurred throughout the outbreak sequence, and repeated rounds of heavy rain caused widespread severe flash and river flooding across much of Tennessee.
Six people were killed near Ohatchee, Alabama by a low-end EF3 tornado, an EF2 tornado killed one person near Carthage, Texas and a low-end EF4 tornado resulted in one indirect death in Newnan, Georgia. An elderly woman in Mississippi was also killed when a tree uprooted by soft soil and heavy rains fell onto her mobile home on March 24 while a man was killed in Carmel, Indiana when a tree was blown over onto him by damaging winds during a severe thunderstorm late on March 27. Severe flooding also killed seven people in Nashville. At least 37 other people were injured during the outbreak as well.
Meteorological synopsis.
March 24.
The first day of the severe weather outbreak, March 24, was not well forecast. A marginal risk outlook for severe weather was originally issued Eastern Texas into the Lower Mississippi Valley on March 22, highlighting the isolated possibility for all severe hazards. By the day of the event, a slight risk outlook had been issued across the Southern Plains and the ArkLaTex regions, mainly for the threat of large hail. By 2000 UTC, however, an enhanced risk outlook for large hail had been issued and extended from Central to Northeast Texas. Numerous supercells formed that afternoon, producing mainly large hail, although two EFU tornadoes were confirmed. To the east in Mississippi in the town of Centreville, an elderly woman was killed when a severe storm blew a tree onto her mobile home.
March 25–26.
On March 22, the Storm Prediction Center issued a broad 15% risk contour from Eastern Texas to the Central Gulf Coast States, highlighting the potential for multiple rounds of severe storms to move through the region. The next day, a large enhanced risk area was issued over parts of the Lower Mississippi Valley and the Southeast, including most of Mississippi. On March 24, the risk was upgraded to moderate over Central and Northern Mississippi as well as Northwestern Alabama and large portion of Tennessee. On the morning of March 25, the moderate risk was upgraded to a high following the issuance of a 30% hatched risk area for tornadoes from central, eastern and northern Mississippi into northwestern Alabama and southern Tennessee. The high risk was later expanded to include all of northern Alabama southward to the central part of the state. At 16:25 UTC, a Particularly Dangerous Situation tornado watch was issued for western and northern Alabama, northwest Georgia, central and eastern Mississippi, and southern Middle Tennessee. Six more tornado watches would be issued through the rest of the day as well. ;ref name="3/25eventrev" ; ;/ref ;
As the outbreak began, one supercell produced three destructive low-end EF3 tornadoes that were confirmed via radar as it moved across Central Alabama, with the second one prompting a tornado emergency in Shelby County, Alabama. The tornado also damaged the home of James Spann, who was covering the event live on ABC 33/40 at the time and saw the tornado on a traffic camera as it crossed over Oak Mountain. The third tornado produced by this supercell was the deadliest of the outbreak sequence, killing six people in Ohatchee. As the afternoon progressed, more tornadic supercells moved through Alabama, as well as Mississippi, Tennessee, Kentucky, Georgia, and South Carolina, producing numerous tornadoes. Another tornado emergency was issued later that afternoon for Brent and Centreville for a large EF3 tornado. Severe and tornadic activity continued into the overnight hours, with a third tornado emergency being issued shortly after midnight for Newnan and Peachtree City, Georgia due to a large, violent low-end EF4 tornado. Strong winds were felt throughout parts of the Northeastern and Midwestern United States, causing major power outages.
More isolated severe weather was expected over several regions of the country of March 26, including a slight risk area that was issued in portions of Upstate New York and Vermont, where a severe thunderstorm watch was issued. A narrow, but severe squall line pushed through this area in the early afternoon hours, producing consistent wind damage. An embedded circulation within the line also produced an isolated high-end EF1 tornado northeast of Middlebury, Vermont, injuring two people. Severe weather reports were also recorded in the Deep South and the Central Plains.
March 27–28.
A slight risk of severe thunderstorms was issued for March 27 from the Lower Mississippi through Tennessee Valleys on March 25 as another weather system was expected to enter the region. The next morning, a small enhanced risk was issued from the Memphis to the Western Nashville metropolitan areas due to a 10% risk contour for tornadoes. That afternoon, the area was hatched, indicating an increased likelihood for strong tornadoes. The enhanced area was expanded to cover a region from Southern Arkansas to Middle Tennessee on the morning of March 27 with the addition of 30% hatched contours for both wind damage and large hail. The southwestern portion of the enhanced risk was eventually pushed into the ArkLaTex region later that day. Slight and marginal risk areas also covered areas from Eastern Texas and Illinois to North Carolina. Numerous strong to severe thunderstorms formed that afternoon, producing widespread reports of hail and wind damage. There were 19 confirmed tornadoes, including six that were rated EF2, with a fatality occurring from one of them east of Carthage, Texas. Another fatality occurred in Carmel, Indiana when severe thunderstorm winds blew a tree down onto a man while he was in his backyard.
March 28 was expected to feature more severe weather with a 15% risk contour issued from Central South Carolina to the Hampton Roads area in Virginia on March 25. An enhanced risk of severe thunderstorms was then issued for the Hampton Roads area on March 27 due to a 30% hatched area for wind damage. A large portion of Southeast and Eastern United States extending from Southeastern Mississippi to Southern New England were put under slight and marginal risks as well. Wind damage was the main threat, although isolated tornadoes and large hail were also possible. One EF1 tornado did touch down in Alabama during the early morning hours, but despite multiple tornado warnings were issued that afternoon, no other tornadoes were confirmed and no severe reports came from the enhanced risk area. ;ref name="3/28eventrev" ; ;/ref ; However, a line of showers and isolated storms did intensify over Western Maryland, causing widespread wind damage from the Blue Ridge Mountains in Maryland to Central Jersey, including across the entire Delaware Valley. A minor injury occurred in Gap, Pennsylvania due to a barn being blown over while a wind gust was observed in Odessa, Delaware. Some scattered severe weather also occurred in Southeastern United States with an injury occurring when severe thunderstorm winds blew a tree onto a home in Lilburn, Georgia. The severe weather threat ended that night when all the storms pushed offshore into the Atlantic Ocean.
Confirmed tornadoes.
West Blocton–Helena–Eagle Point–Vandiver, Alabama.
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Twenty-three minutes after the Talladega National Forest low-end EF3 tornado lifted, the same parent supercell thunderstorm produced this intense, long-tracked tornado that caused significant damage in the southern suburbs of Birmingham. It first touched down along Vance Road west of West Blocton in Bibb County at 12:53 p.m. CDT (17:53 UTC) and moved northeastward, damaging trees at EF0 to EF1 strength. It quickly strengthened as it passed north of town and briefly reached low-end EF2 intensity, snapping large tree trunks in a wooded area. It then weakened back to EF1 strength, uprooting trees near Hebron before weakening further, causing high-end EF0 damage northeast of the rural community. The tornado then moved into Shelby County, briefly reaching low-end EF1 strength as it uprooted trees. EF1 damage continued south of Turner, as it uprooted more trees before weakening back to EF0 strength as it entered the west side of Helena, causing minor roof damage to homes and downing trees. Mainly shingle, siding, and fence damage was noted in this area, though a house that was under construction collapsed. The tornado then intensified to EF1 strength once again as it moved through the north side of Helena. A few homes along Cunningham Lane sustained partial roof loss, and one home in town sustained destruction of its front porch overhang. The tornado briefly weakened back to EF0 strength before strengthening more significantly at the north edge of Pelham, reaching EF2 intensity as it moved directly through a residential neighborhood. Several homes were significantly damaged along Crosscreek Trail and Wilderness Road, including a few that had their roofs ripped off, and at least two that had an exterior wall knocked down. Trees were uprooted or severely damaged as well. The tornado then continued northeast at EF1 strength, damaging or snapping numerous trees as it moved farther into the southern suburbs of Birmingham, and proceeded to cross US 31 and I-65. A few mobile homes and some businesses sustained roof damage along this corridor. East of the interstate, a manufactured home was completely destroyed at high-end EF1 intensity and more trees were damaged. More trees were snapped along Indian Trail as the tornado traversed mountainous terrain into Indian Springs Village, where additional trees were downed and homes sustained minor to moderate damage. As the tornado passed New Hope, it briefly regained low-end EF2 intensity as it paralleled SR 119, snapping several tree trunks and uprooting more trees, some of which fell on homes in a neighborhood. The tornado then caused high-end EF0 to EF1 damage to homes and trees in another neighborhood before briefly reaching low-end EF2 strength again as it moved directly over SR 119, where more large tree trunks were snapped.
The tornado then caused EF1 tree damage as it passed over Beaver Lake and Lunker Lake, before reaching its peak intensity as it struck the Eagle Point neighborhood just east of Meadowbrook. One home in the area lost its roof and most exterior walls, while another poorly-anchored home was pushed off its foundation and leveled. Damage to these two homes was rated low-end EF3. Multiple other homes in the neighborhood suffered up to high-end EF2 damage, including one that was shifted off its foundation, and others which sustained varying degrees of roof and exterior wall loss. Trees in the area were also heavily damaged. A tornado emergency was issued for this storm shortly before the tornado struck the neighborhood, as a large debris ball was seen on radar. Northeast of this location, the tornado continued at EF2 strength, and more homes and trees suffered heavy damage as the tornado approached and crossed over US 280. Homes in neighborhoods along the west side of the highway sustained roof loss, along with some collapse of exterior walls. Continuing northeastward past the highway, the tornado momentarily became weak again, causing EF1 damage to trees and the roofs of homes. The now large tornado was then seen live on ABC 33/40 via a traffic camera at the intersection of US 280 and SR 119 as it crossed Oak Mountain. As the tornado approached Double Oak Mountain, it again attained EF2 strength and struck additional residential areas along Dunnavant Valley Road. Some of the most severe damage in this area occurred in the Greystone Farms subdivision, where homes sustained varying degrees of roof loss, and some had their roofs torn off entirely. Moving farther to the northeast, additional EF2 damage to many trees and a few homes occurred at the Shoal Creek Country Club. The tornado briefly reached peak strength for a second time as it moved through a wooded area at the country club, producing a small area of EF3-level tree damage. It then weakened to EF1 strength as it moved over Double Oak Mountain and struck Vandiver, uprooting trees, and damaging several homes on the northeast side of town. Past Vandiver, high-end