1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado
A destructive severe weather episode affected portions of the Midwestern and Southern United States from April 30–May 2, 1967. It consisted of two consecutive tornado outbreaks that generated at least 38 tornadoes, causing 13 fatalities and 90 injuries. All of the deaths occurred on April 30, which is known as the 1967 Iowa–Minnesota tornado outbreak, or Black Sunday, to residents of Iowa and southern Minnesota. That day spawned a total of 21 tornadoes, devastating the towns of Albert Lea and Waseca, Minnesota.[6][7][nb 2][nb 3]
This tornado struck the western portion of the community of Halfa, tearing the roofs off several homes. While passing east of Gridley, it also destroyed barns.[27]
This tornado destroyed barns, agricultural machinery, and one home. Observers reported three distinct funnel clouds. Grazulis listed the tornado as an F2.[27][28]
2 deaths – Near the start of its path, this tornado neared the threshold of F4-level intensity, based on structural damage to farms. Additionally, the tornado destroyed barns. Twenty-three people sustained injuries.[27][30]
5 deaths – This destructive, long-tracked tornado caused $2 million in damages in Albert Lea alone. The tornado ravaged the western portion of the town; there, it significantly damaged 55 homes, and "completely leveled" 10 others. In all, the tornado destroyed 26 homes and severely damaged an additional 64 in Albert Lea. Along its entire path, the tornado flattened farms at six different locations. The tornado also destroyed many structures on farms near Owatonna. The tornado injured a total of 35 people.[29][32][33]
6 deaths – This tornado was the last violent event of the entire outbreak sequence. It paralleled Minnesota State Highway 13, known then as Highway 67, and damaged farms on each side of the highway. In Waseca, the tornado leveled six homes, destroyed 16, and extensively damaged 25. The tornado injured 22 people.[29][34]
A brief tornado destroyed a barn and a livestock pen. Fencing was wrenched from the ground as well. Grazulis did not list this tornado as an F2 or stronger.[14][35]
A brief tornado destroyed a pair of chicken coops and damaged a number of large livestock feeders. Trees were downed as well. Grazulis did not list this tornado as an F2 or stronger.[14][35]
A brief tornado, coincident and possibly in conjunction with downbursts, flipped a mobile home and damaged or destroyed a few houses and several barns. A large pecan was prostrated as well. Grazulis did not list this tornado as an F2 or stronger.[14][35]
A brief tornado affected a 600-acre (240 ha) conservation area as it tossed and sank forty motorboats, some of which were wrapped around trees. Additionally, the tornado tore a section from a 200-foot-long (61 m) pier, severely damaged several trees, and tilted a concession stand. Grazulis did not list this tornado as an F2 or stronger.[14][38]
This tornado may have first begun in Point Blank, on the opposite shore of the Trinity River. In and near Point Blank, trees sustained damage, a church was destroyed, and homes were damaged. However, official data indicate that the tornado first impacted Onalaska, on the eastern side of Lake Livingston. In Onalaska, the tornado unroofed a combined store and post office; the building itself also lost its rear wall. The tornado injured two people, and losses reached $25,000.[29][39][40][41]
A brief tornado caused sizeable damage to trees, splintered utility poles, and partly unroofed a building. Several other structures were substantially damaged, one of which had its steel doors knocked down. Additionally, a horse died as a barn collapsed during the tornado. Grazulis did not list this tornado as an F2 or stronger.[14][43]
A brief tornado affected 35 homes and businesses as it passed through Kaplan. Four people were injured. Grazulis did not list this tornado as an F2 or stronger.[14][37][45]
A brief tornado dislodged a house, flipped a nearby mobile home, and downed a large tree. A utility room and a carport were torn loose as well. Grazulis did not list this tornado as an F2 or stronger.[14][38]
A brief tornado significantly damaged three homes and slightly damaged about forty others. Windows, signage, and canopy-forming vegetation were broken. Grazulis did not list this tornado as an F2 or stronger.[14][47]
^All losses are in 1967 USD unless otherwise noted.
^An outbreak is generally defined as a group of at least six tornadoes (the number sometimes varies slightly according to local climatology) with no more than a six-hour gap between individual tornadoes. An outbreak sequence, prior to (after) the start of modern records in 1950, is defined as a period of no more than two (one) consecutive days without at least one significant (F2 or stronger) tornado.[8][9][10][11][12][13]
^The Fujita scale was devised under the aegis of scientist T. Theodore Fujita in the early 1970s. Prior to the advent of the scale in 1971, tornadoes in the United States were officially unrated.[14] While the Fujita scale has been superseded by the Enhanced Fujita scale in the U.S. since February 1, 2007,[15]Canada utilized the old scale until April 1, 2013;[16] nations elsewhere, like the United Kingdom, apply other classifications such as the TORRO scale.[17]
^ abcAll dates are based on the local time zone where the tornado touched down; however, all times are in Coordinated Universal Time and dates are split at midnight CST/CDT for consistency.
^ abcPrior to 1994, only the average widths of tornado paths were officially listed.[25]
References
^National Weather Service (30 September 2019). Grazulis, Thomas P.; Grazulis, Doris (eds.). Tornado History Project: Maps and Statistics. Tornado History Project (Report). The Tornado Project of Environmental Films. Retrieved 2 January 2021.
^National Weather Service (30 September 2019). Grazulis, Thomas P.; Grazulis, Doris (eds.). Tornado History Project: Maps and Statistics. Tornado History Project (Report). The Tornado Project of Environmental Films. Retrieved 2 January 2021.
U.S. Weather Bureau (May 1967b). "Storm Data and Unusual Weather Phenomena". Storm Data. 9 (5). Asheville, North Carolina: National Climatic Data Center.
National Weather Service (April 1967a). Storm Data Publication (Report). National Centers for Environmental Information – via Storm Events Database.
National Weather Service (May 1967b). Storm Data Publication (Report). National Centers for Environmental Information – via Storm Events Database.
