Tornado outbreak of February 21–22, 1971

Tornado outbreak of February 21–22, 1971

Tornado tracks on February 21–22, 1971
Type	Tornado outbreak
Duration	February 21–22, 1971
Highest gust	50 kn (58 mph; 93 km/h) in Alabama on February 21
Tornadoes confirmed	≥ 19
Max. rating1	F5 tornado
Duration of tornado outbreak2	1 day, 9 hours, 15 minutes
Largest hail	1+3⁄4 in (4.4 cm) in Alabama and Ohio on February 22
Fatalities	123 deaths, 1,592 injuries
Damage	$45.901 million (1971 USD) $345 million (2024 USD)
Areas affected	Southern United States (primarily the Mississippi Delta), Great Lakes region
Part of the tornadoes and tornado outbreaks of 1971 1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado

From Sunday to Monday, February 21–22, 1971, a devastating tornado outbreak, colloquially known as the Mississippi Delta outbreak, struck portions of the Lower Mississippi and Ohio River valleys in the Southern and Midwestern United States. The outbreak generated strong tornadoes from Texas to Ohio and North Carolina. The two-day severe weather episode produced at least 19 tornadoes, and probably several more, mostly brief events in rural areas; killed 123 people across three states; and wrecked entire communities in Mississippi. The strongest tornado of the outbreak was an F5 that developed in Louisiana and crossed into Mississippi, killing 48 people, while the deadliest was an F4 that tracked across Mississippi and entered Tennessee, causing 58 fatalities in the former state. The former tornado remains the only F5 on record in Louisiana, while the latter is the deadliest on record in Mississippi since 1950. A deadly F4 also affected other parts of Mississippi, causing 13 more deaths. Other deadly tornadoes included a pair of F3s—one each in Mississippi and North Carolina, respectively—that collectively killed five people.

Background

Surface weather analysis at 12:00 UTC on February 21

At 12:00 UTC on February 21, 1971, surface weather analysis failed to indicate either a well-developed low-pressure area or a defined frontal boundary over the Gulf Coastal Plain, signs that would normally presage a severe weather outbreak. At the time, a diffuse warm front extended eastward from East Texas to portions of Mississippi, and a cold front extended southward over East Texas. Higher up in the atmosphere, conditions were "close to ideal" for a significant tornado outbreak: a broad trough imparted substantial divergence over the prefrontal warm sector.

Impact

Activity started early on the morning of February 21. The first tornadoes touched down in Texas east of Austin and north of Waco. The main activity intensified during the afternoon over the Mississippi and Tennessee Valleys until the late evening hours. At 15:55 UTC the National Severe Storms Forecast Center (NSSFC) in Kansas City, Missouri, issued a tornado watch for eastern Arkansas, northern Mississippi, and adjourning portions of Tennessee and Alabama. A subsequent watch covered portions of eastern Louisiana and southwestern Mississippi, more than an hour before the first major tornado developed.

Upper-air analysis at 12:00 UTC on February 21

Three violent, long-lived tornadoes—two of which may have been tornado families—in western Mississippi and northeastern Louisiana caused most of the deaths along 330 mi (530 km) of path. The first of the three long-lived violent tornadoes was an F5 that touched down in Louisiana and traveled continuously for 102 mi (164 km), followed by an F4 in Mississippi that produced continuous damage for 159 mi (256 km) and continued into Tennessee. A third, F4 tornado traveled 65 mi (105 km) through Little Yazoo, Mississippi, and near Lexington. The three violent tornadoes moved at up to 55 mph (89 km/h), and eyewitnesses reported more than 50 tornadoes or funnel clouds in the Mississippi Delta region alone, many of which were sightings of the same tornado. At one point, the National Weather Service (NWS) WSR-57, a type of weather radar, in Jackson, Mississippi, reported four hook echoes, often indicative of tornado-producing supercells, simultaneously.

Although authorities issued timely tornado warnings—with an average lead time of about an hour in the worst-hit areas—few homes in the area were well constructed, and many lacked basements or other safe areas, thus contributing to the large number of deaths. Many residents were reportedly aware of the danger but could not find shelter in time. As a result, the violent tornadoes killed entire families and caused as many as 21 deaths in some communities. Many of the dead were blacks who resided in frail structures. The entire outbreak may have killed 113–119 people and injured as many as 2,003 others. In Mississippi alone, tornadoes officially killed 110 people and injured 1,469; of these, 454 persons were hospitalized. Some sources listed 107 deaths and 1,060–1,514 injuries in Mississippi.

Outbreak statistics

Outbreak death toll

State	Total	County	County total
Louisiana	11	Madison	11
Mississippi	110	Humphreys	32
		Leflore	14
		Sharkey	23
		Sunflower	28
		Warren	2
		Yazoo	11
North Carolina	2	Cumberland	2
Totals	123
All deaths were tornado-related

Confirmed tornadoes

Confirmed tornadoes by Fujita rating

FU	F0	F1	F2	F3	F4	F5	Total
0	2	4	7	3	2	1	≥ 19*

• The actual total was likely considerably higher, especially over rural areas. The following events may have occurred but were not officially documented and currently do not appear on any official database:
  • On February 21, between 15:25–15:35 UTC, a funnel cloud and possible tornado may have occurred during a severe thunderstorm at Athens, Henderson County, Texas. One resident reported a "roaring" noise like that of many freight trains, but a tornado was not believed to have developed.
  • On February 21, at 00:30 UTC, a tornado may have hit Toccopola, Pontotoc County, Mississippi, according to a report by the National Oceanic and Atmospheric Administration (NOAA).
  • On the same date a 15-mile-long (24 km), 200-yard-wide (180 m; 600 ft) tornado began at 02:31 UTC, near Statesville, Wilson County, Tennessee, and passed through Prosperity before ending at Liberty, in DeKalb County. In all, the tornado destroyed or severely damaged 10 homes, 15 barns, and 14 other structures, along with a spacious brick church. Half a dozen cars were damaged as well, and at least one home lost its roof. Tornado researcher Thomas P. Grazulis listed the tornado as an F3.

February 21 event

Confirmed tornadoes – Sunday, February 21, 1971

F#	Location	County / Parish	State	Start coord.	Time (UTC)	Path length	Max. width	Summary
F2	Bellmead	McLennan	TX	31.62°N 97.10°W / 31.62; -97.10 (Bellmead (February 21, F2))	13:30–?	0.1 mi (160 m)	17 yd (16 m)	This brief-but-strong tornado struck downtown Bellmead, severely damaging several businesses, some of which lost roofs and walls. A shopping center, a bank, and a post office were among the establishments affected. Additionally, one home had its roof torn off and a trailer was destroyed. Losses totaled $250,000. The National Centers for Environmental Information (NCEI) Storm Events Database incorrectly lists the touchdown as having occurred in Lacy Lakeview.
F1	SW of Lincoln	Lee	TX	30.28°N 96.97°W / 30.28; -96.97 (Lincoln (February 21, F1))	14:15–?	0.3 mi (480 m)	10 yd (9.1 m)	A brief, narrow tornado tore off an awning and part of a steel roof, carrying them about 100 ft (33 yd) and pulling three awning posts out of the ground. 2-by-4-inch (51 by 102 mm) lumber pieces were driven into the ground as well and could not be dislodged. Losses totaled $250.
F5	SE of County Landing, LA to Inverness, MS to S of Schlater, MS	Madison (LA), East Carroll (LA), Issaquena (MS), Sharkey (MS), Washington (MS), Humphreys (MS), Sunflower (MS), Leflore (MS)	LA, MS	32.38°N 91.47°W / 32.38; -91.47 (County Landing (February 21, F5))	20:50–23:10	109.2 mi (175.7 km)	500 yd (460 m)	48 deaths – See article on this tornado – 510 people were injured. The rating is disputed. Grazulis listed 400 injuries.
F2	S of Collins to E of McGehee	Drew, Chicot, Desha	AR	33.45°N 91.57°W / 33.45; -91.57 (Collins (February 21, F2))	21:00–?	17.1 mi (27.5 km)	300 yd (270 m)	Numerous trees were downed. A pair of homes were severely damaged, while a number of others and a municipal park incurred minor impacts. Damage was not continuous and was of low-end F2 intensity at most. Losses totaled $250,000.
F4	New Fitler, MS to Pugh City, MS to WSW of Poor, TN	Issaquena (MS), Sharkey (MS), Humphreys (MS), Leflore (MS), Grenada (MS), Tallahatchie (MS), Yalobusha (MS), Lafayette (MS), Marshall (MS), Benton (MS), Tippah (MS), Hardeman (TN)	MS, TN	32.70°N 91.02°W / 32.70; -91.02 (New Fitler (February 21, 1971))	22:00–02:30	202.1 mi (325.2 km)	100 yd (91 m)	58 deaths – See section on this tornado – 795 people were injured and losses were unknown. Grazulis listed 700 injuries.
F2	E of Colt to Southeastern Wynne	St. Francis, Cross	AR	35.15°N 90.78°W / 35.15; -90.78 ((February 21, F2))	23:00–?	4.6 mi (7.4 km)	100 yd (91 m)	This tornado damaged many structures, including a brick home and mobile homes. Two barns were destroyed as well. Losses totaled $25,000. Grazulis did not list the tornado as an F2 or stronger.
F4	SSE of Bovina to Little Yazoo to ESE of Jones Crossing	Warren, Yazoo, Holmes	MS	32.33°N 90.73°W / 32.33; -90.73 (Bovina (February 21, F4))	23:06–00:16	65.2 mi (104.9 km)	33 yd (30 m)	13 deaths – The final long-lived violent tornado of the outbreak destroyed barns and homes, including a guest house, near Bovina, as well as approximately 100 pecan trees. One home was obliterated, with only concrete blocks remaining on its foundation, and two people died of injuries. Next, the tornado passed through and destroyed Little Yazoo, where many homes, businesses, and a church were leveled and swept away, resulting in nine fatalities. Beyond Little Yazoo, near Bentonia, the tornado killed two more people. In all, in the Little Yazoo–Bentonia area the tornado leveled 12 homes. In Holmes County, the tornado struck the community of Brozville, extensively damaging homes, barns, chicken coops, and sheds. It finally dissipated near Lexington. In all, the tornado leveled many homes along the path and injured 182 people. Losses were unknown. Grazulis listed 200 injuries and a 70-mile-long (110 km) path, while a report by NOAA indicated that the path was 69 mi (111 km) long.
F3	WNW of Whitney to Parchman to NE of Rome	Sunflower	MS	33.85°N 90.52°W / 33.85; -90.52 (Whitney (February 21, F3))	23:30–?	8.6 mi (13.8 km)	33 yd (30 m)	3 deaths – This tornado damaged a number of homes in Parchman. A cotton gin and several tenant homes were wrecked in and near Rome. Losses were unknown. The tornado may have begun half an hour or more earlier than is listed officially. Grazulis classified the tornado as an F2. Both Grazulis and Storm Data only listed two fatalities, though the NCEI listed three. Grazulis also listed five injuries.
F0	SSE of McRaven	Hinds	MS	32.28°N 90.32°W / 32.28; -90.32 (McRaven (February 21, F0))	00:54–00:55	0.1 mi (160 m)	33 yd (30 m)	A brief touchdown produced little or no damage. Losses were unknown.
F2	SSW of Snow Lake Shores	Benton	MS	34.77°N 89.27°W / 34.77; -89.27 (Snow Lake Shores (February 21, F2))	01:00–02:00	0.1 mi (160 m)	33 yd (30 m)	This tornado may have been produced by the same storm as the Cary–Pugh City F4, but more probably was related to a separate storm, based on an hour-long lapse between reported tornadoes. It downed trees and power lines between Holly Springs and Ashland. Losses were unknown. The tornado may have occurred near 01:40 UTC. Grazulis did not list the tornado as an F2 or stronger.
F1	ENE of Sinai	Rankin	MS	32.13°N 90.17°W / 32.13; -90.17 (Sinai (February 21, F1))	01:10–?	0.1 mi (160 m)	33 yd (30 m)	With a "loud roar" a brief tornado uplifted a vehicle, crossing a road between Florence and Plain. Losses were unknown.
F0	Eastern Pearl	Rankin	MS	32.28°N 89.98°W / 32.28; -89.98 (Pearl (February 21, F0))	01:35–?	0.1 mi (160 m)	33 yd (30 m)	A brief tornado felled utility wires and trees at the McLaurin Shopping Center. Losses were unknown.
F2	Hurricane	Pontotoc	MS	34.27°N 88.98°W / 34.27; -88.98 (Hurricane (February 21, F2))	02:30–?	0.1 mi (160 m)	33 yd (30 m)	This narrow-but-strong tornado flung roofing and assorted debris for several hundred yards. A school was wrecked and nearby structures on site were damaged as well, along with a pair of stores and a church. Losses were unknown.
F2	Southeastern Selmer	McNairy	TN	35.15°N 88.58°W / 35.15; -88.58 (Selmer (February 21, F2))	03:35–?	1.5 mi (2.4 km)	67 yd (61 m)	This strong tornado destroyed or damaged about 40 homes and 15 businesses. The tornado injured 36 people, of whom six were hospitalized, and caused $21⁄2 million in damage. Grazulis classified the tornado as an F3 and noted $1 million in losses.

February 22 event

Confirmed tornadoes – Monday, February 22, 1971

F#	Location	County / Parish	State	Start coord.	Time (UTC)	Path length	Max. width	Summary
F1	WSW of Letts Corner to WNW of Greensburg	Decatur	IN	39.23°N 85.60°W / 39.23; -85.60 (Letts Corner (February 22, F1))	18:00–18:10	9.1 mi (14.6 km)	80 yd (73 m)	This tornado damaged a garage, the upper part of a house, and a pair of barns. An airplane was overturned as well. Two people were injured and losses totaled $25,000.
F1	S of Riley to ENE of Wiles Crossroads	Calhoun	SC	33.62°N 80.80°W / 33.62; -80.80 (Riley (February 22, F1))	21:20–21:45	11.9 mi (19.2 km)	80 yd (73 m)	This tornado passed near St. Matthews, unroofing a pair of small homes and a factory. A "roaring" din was noted. Losses totaled $25,000. Grazulis classified the tornado as an F2.
F2	ESE of Pancoastburg	Fayette, Pickaway	OH	39.62°N 83.25°W / 39.62; -83.25 (Pancoastburg (February 22, F2))	21:25–?	2 mi (3.2 km)	100 yd (91 m)	Agricultural outbuildings were damaged near Deer Creek. Losses totaled $25,000. Grazulis did not list the tornado as an F2 or stronger.
F3	Northern Bexley to NW of Havens Corner	Franklin	OH	39.97°N 82.93°W / 39.97; -82.93 (Bexley (February 22, F3))	21:55–?	6.8 mi (10.9 km)	100 yd (91 m)	This intense tornado moved through eastern Columbus, producing near-continuous damage for its duration. Numerous homes and warehouses were wrecked, while other structures were unroofed, with losses reaching $21⁄2 million. Seven people were injured. Grazulis classified the tornado as an F2 and noted $24⁄5 million in losses.
F3	Northwestern Fayetteville to Wade to Falcon to SSW of Sharp Point	Cumberland, Sampson, Johnston, Wayne, Wilson, Greene, Pitt, Edgecombe	NC	35.08°N 78.92°W / 35.08; -78.92 (Fayetteville (February 22, F3))	22:30–02:00	85.7 mi (137.9 km)	500 yd (460 m)	2 deaths – This tornado tracked continuously for its first 20 mi (32 km), destroying 40 homes—some of which incurred borderline-F4 damage, with only innermost walls left intact—and damaging another 325. The rest of the path may have involved several distinct, brief tornadoes of weaker intensity. 60 people were injured and losses totaled $23⁄4 million. Grazulis and Storm Data listed 64 injuries. All casualties occurred in the earliest part of the path.

Delhi-Waverly–Melbourne, Louisiana/Delta City–Inverness–Moorhead, Mississippi

Main article: 1971 Inverness tornado

Delhi-Waverly–Melbourne, Louisiana/Delta City–Inverness–Moorhead, Mississippi

F5 tornado
Damage in Inverness, Mississippi
Max. rating1	F5 tornado
Fatalities	48 fatalities, 510 injuries
Damage	unknown
1Most severe tornado damage; see Fujita scale

This devastating, long-lived tornado—of F5 intensity in Louisiana, F4 in Mississippi—was likely a family of multiple tornadoes. It first appeared aloft northwest of Crowville, Louisiana, before finally touching down south-southeast of Delhi. Shortly after developing, the tornado moved northeastward at an average speed of 52 mph (84 km/h), bypassing the small community of Waverly. Along and northeast of U.S. Route 80, the tornado completely leveled a number of small homes at F5 intensity, though the homes may not have been well constructed. About 3 mi (4.8 km) east of Delhi, on a farmstead in Joes Bayou, it killed 10 people in a family of 12, five of whose bodies were thrown into nearby swamps and not located for weeks. Three other homes, a rural church, and half a dozen large, overhead power lines were destroyed nearby. In all, the tornado destroyed as many as seven homes in the Delhi–Waverly area. After devastating Joes Bayou, the tornado mostly traversed unpopulated, forested country for the remainder of its path in Louisiana. As it continued northeastward, however, the tornado struck the Melbourne settlement on Pecan Road, a short distance south of Transylvania, near Alsatia. At Melbourne the tornado destroyed a pair of mobile homes and seven homes. 13 other mobile homes, 11 outbuildings, and a mature pecan grove were severely damaged as well. Vehicles and agricultural implements were tossed about, but only minor injuries occurred. In all, the tornado killed 11 people and injured 18 others in Louisiana, though some sources do not list the eleventh fatality. After striking Melbourne, the tornado crossed the Mississippi River and entered Mississippi. In 1984 and 1993 tornado researcher Thomas P. Grazulis assessed the tornado as having caused F4 damage in Louisiana, but in 2001 revised this to accept the official F5 rating.

Once in Mississippi, the tornado passed near Mayersville in Issaquena County. As it did so, it began to slowly weaken in intensity. It either began to restrengthen or dissipated and reformed as a new tornado in Sharkey County. This possible new tornado went on to produce F4 damage and retained intensity until dissipation. The tornado killed two people near Cameta and destroyed a cotton gin near Nitta Yuma. The tornado then devastated Delta City, killing seven people and destroying the entire community. The tornado continued northeastward, claiming two additional lives west of Isola. Afterward, it entered the town of Inverness as a large tornado, destroying an estimated 80–90% of the community, killing 21 people, and injuring 200 more. In town the tornado destroyed 125–153 homes, along with 40 other structures. 52 homes were badly damaged as well, 61 businesses were destroyed or damaged, and 30 outbuildings were destroyed on farms. The tornado destroyed the entire central business district, city hall, the three largest churches in town, and entire blocks of frail homes in the African-American section of town; many of these homes were "obliterated." Hundreds of people were left homeless, and railcars were tipped onto their sides. The tornado then leveled the northwestern side of Moorhead, killing four people there before ending near Schlater. In all, the tornado destroyed hundreds of homes along its path. It is the only official F5/EF5 to have hit the state of Louisiana since official tornado records began in 1950 and the only F5/EF5 tornado ever recorded in the month of February, although the F5 rating is disputed as many of the houses destroyed were small and frail. It was also the deadliest F5 tornado since the Candlestick Park tornado in 1966 killed 58 people across Mississippi and Alabama, but was later eclipsed by an EF5 tornado on April 27, 2011, that killed 72 people.

Cary–Gooden Lake–Pugh City–Morgan City–Money, Mississippi/Middleton, Tennessee

Cary–Gooden Lake–Pugh City–Morgan City–Money, Mississippi/Middleton, Tennessee

F4 tornado
Damage in Pugh City, Mississippi
Max. rating1	F4 tornado
Fatalities	58 fatalities, 795 injuries
1Most severe tornado damage; see Fujita scale

This, the deadliest and longest-lived of the three violent tornadoes, was likely a tornado family. It first touched down just southeast of Fitler, approximately 6–8 mi (9.7–12.9 km) southwest of Cary, and moved northeastward. Just south of Cary, the tornado destroyed the Evanna Plantation, killing 14 people there. The tornado then struck Cary, destroying the entire community. Continuing to the northeast, the tornado struck Gooden Lake, killing seven people there, and then struck Mound Lake Plantation, causing two additional fatalities. The tornado then passed through and completely destroyed the Joe Regh Plantation at Pugh City, reducing frail, low-income housing to "splinters," rolling farm machinery, and killing at least 21 people. Some sources listed an extra fatality at Pugh City. Extensive wind-rowing occurred as frame homes were completely swept away. The tornado killed two more people in Swiftown; six in Morgan City; two a few miles west of Greenwood, near Fort Loring; and four near Money. The tornado may have weakened and reformed into a separate event that passed through or near Avalon, Oxberry, Cascilla, and Tillatoba, causing scattered damage in those communities. Isolated stands of mature trees and willows were twisted, splintered, or prostrated, and outbuildings on farms were damaged. Bits of roofing, insulation, and wallpaper were torn off in Tillatoba.

This tornado then lifted and reformed into one or more tornadoes west of Oxford, destroying more than 31 mobile homes in trailer parks, passing near the University of Mississippi campus, and producing a path of 10 mi (16 km) or longer through the Holly Springs National Forest. This series of tornadoes apparently dissipated and reformed yet again near Abbeville. Areas in and near Oxford reported $500,000 in damage, the worst natural disaster in local history. Between Avalon and the Holly Springs National Forest the path ranged from 200 to 800 yd (600 to 2,400 ft; 180 to 730 m) in width. Yet another or more tornadoes may have caused damage between Bethlehem and Oakland, Mississippi, before continuing into Tennessee, where F3 damage occurred 5 mi (8.0 km) southwest of Middleton; there three homes were damaged, one of which was destroyed, with $40,000 in losses. A 24-by-60-foot (7.3 by 18.3 m) mobile home lost its roof and most of its walls. Several large trees were downed or splintered as well. The tornado dissipated shortly thereafter. Its path was just a few miles east of the areas affected by the F5 tornado for most of its path, and several counties were affected by both tornadoes. With 58 fatalities, the tornado is the deadliest in Mississippi since 1950; however, the deadliest Mississippi tornado on record in the 20th century killed 216 people in 1936.

Non-tornadic effects

The outbreak generated severe thunderstorm winds, from Texas to Kentucky and North Carolina; winds peaked at 50 kn (58 mph; 93 km/h) in Tuscaloosa County, Alabama, on February 21. These strong winds damaged utility lines, vegetation, agricultural outbuildings, warehouses, porches, mobile homes, and barns. At least one built-up roof was partly torn off, along with tar paper. On February 21 at Athens, Henderson County, Texas, vigorous winds caused minor injuries to seven people, all of which took place in trailers. Roofing, a drive-in theater screen, and up to 500 television antennae were downed or otherwise damaged. Hail of up to 1+3⁄4 in (4.4 cm) in diameter was reported in Alabama and Ohio as well, including golfball-sized stones in Cambridge and Toledo, Ohio. The publication Storm Data noted that the hail in Ohio peaked at 1 in (2.5 cm) diameter.

Aftermath, recovery, and records

An internal assessment by the Mississippi Power and Light Company determined that its infrastructure incurred the greatest wind-related damage in the company's history. Roughly half of its transmission towers were damaged in both Sharkey and Humphreys counties.

One of the tornadoes attained F5 intensity in Louisiana, the only such event on record in the state, although the rating is disputed. The entire outbreak is the second-deadliest ever in February, behind only the Enigma tornado outbreak in 1884 and ahead of the 2008 Super Tuesday tornado outbreak. February 21 was the fourth-deadliest day for tornadoes in Mississippi on record.

See also

• List of North American tornadoes and tornado outbreaks
• List of F5 and EF5 tornadoes
• 2008 Super Tuesday tornado outbreak – Second deadliest outbreak on record in February
• Tornado outbreak of March 24–27, 2023 – Similar deadly tornado outbreak in the Mississippi Delta

Sources

• Brooks, Harold E. (April 2004). "On the Relationship of Tornado Path Length and Width to Intensity". Weather and Forecasting. 19 (2): 310–19. Bibcode:2004WtFor..19..310B. doi:10.1175/1520-0434(2004)019<0310:OTROTP>2.0.CO;2.
• Cook, A. R.; Schaefer, J. T. (August 2008). "The Relation of El Niño–Southern Oscillation (ENSO) to Winter Tornado Outbreaks". Monthly Weather Review. 136 (8): 3135. Bibcode:2008MWRv..136.3121C. doi:10.1175/2007MWR2171.1.
• Grazulis, Thomas P. (May 1984). Violent Tornado Climatography, 1880–1982. OSTI (Technical report). NUREG. Washington, D.C.: Nuclear Regulatory Commission. OSTI 7099491. CR-3670.
• Grazulis, Thomas P. (November 1990). Significant Tornadoes 1880–1989. Vol. 2. St. Johnsbury, Vermont: The Tornado Project of Environmental Films. ISBN 1-879362-02-3.
• Grazulis, Thomas P. (July 1993). Significant Tornadoes 1680–1991: A Chronology and Analysis of Events. St. Johnsbury, Vermont: The Tornado Project of Environmental Films. ISBN 1-879362-03-1.
• Grazulis, Thomas P. (2001a). The Tornado: Nature's Ultimate Windstorm. Norman, Oklahoma: University of Oklahoma Press. ISBN 978-0-8061-3538-0.
• Grazulis, Thomas P. (2001b). F5-F6 Tornadoes. St. Johnsbury, Vermont: The Tornado Project of Environmental Films.
• Mississippi Delta Tornadoes of February 21, 1971 (PDF) (Technical report). Natural Disaster Survey Report. Rockville, Maryland: United States Department of Commerce. July 1971. 71-2, A Report to the Administrator.
• Neal, Lott; Sam McCown; Tom Ross (August 2000) [1999]. 1998-1999 Tornadoes and a Long-Term U.S. Tornado Climatology (PDF) (Technical report). National Climatic Data Center Technical Report. Asheville, North Carolina: National Climatic Data Center. 99-02.
• National Weather Service (February 1971). "Storm Data and Unusual Weather Phenomena". Storm Data. 13 (2). Asheville, North Carolina: National Climatic Data Center.
• National Weather Service (February 1971). Storm Data Publication (Report). National Centers for Environmental Information – via Storm Events Database.
• National Weather Service; Saltsman, E. J. (February 1971). Written at Jackson, Mississippi. "Special Weather Summary". Mississippi section. Climatological Data. 76 (2). Asheville, North Carolina: United States Department of Commerce: 15–8.
• Super Tuesday Tornado Outbreak of February 5-6, 2008 (PDF) (Technical report). Service Assessment. Silver Spring, Maryland: United States Department of Commerce. March 2009. Archived from the original (PDF) on 4 December 2010.