Several unconfirmed tornadoes were also reported: •
May 20: tornadoes were reported south of
Solomon Rapids, Kansas, and east of
Concordia, Kansas. Prior to 1990, there is a likely undercount of tornadoes, particularly E/F0–1, with reports of weaker tornadoes becoming more common as population increased. A sharp increase in the annual average E/F0–1 count by approximately 200 tornadoes was noted upon the implementation of
NEXRAD Doppler weather radar in 1990–1991. 1974 marked the first year where significant tornado (E/F2+) counts became homogenous with contemporary values, attributed to the consistent implementation of
Fujita scale assessments. Numerous discrepancies on the details of tornadoes in this outbreak exist between sources. The total count of tornadoes and ratings differs from various agencies accordingly. The list below documents information from the most contemporary official sources alongside assessments from tornado historian
Thomas P. Grazulis.
May 19 event May 20 event May 21 event May 22 event Williamsburg−Spring Hill, Kansas/Ruskin Heights–Raytown, Missouri This violent, long-tracked,
multiple-vortex event was likely a family of tornadoes. Forming near Williamsburg, it moved northeastward through several counties, producing near-continuous damage; a single tornado was likely present for or more. Around
Homewood, the tornado was attended by up to 10 tentacle-like vortices or satellite tornadoes, producing major damage to rural property and carrying gravestones miles away. Passing near
Ottawa,
Rantoul, and
Spring Hill, it leveled many homes and caused seven fatalities. It also damaged a drive-in, motel, and truck stop. South of
Wellsville, the tornado may have dissipated and reformed; it then continued uninterruptedly for the rest of its life. Along the Kansas–Missouri border the tornado followed a near-straight line, causing $1 million in losses in Kansas. Affecting the southern suburbs of
Kansas City, it entered Missouri, tearing through
Martin City,
Hickman Mills, and Ruskin Heights, along with the northeastern side of
Grandview. Housing incurred F5 damage, besides some businesses at a shopping center. Some areas were reportedly "swept clean", and a newly built brick school in Ruskin Heights was badly damaged. 85% of Martin City was uninhabitable. In all the tornado claimed 37 lives in Missouri and injured 500 or more people. Debris from Hickman Mills was found in Iowa, away, and other debris was carried aloft . Historically, the 1957 F5 was not the only significant tornado to affect the area: an F3 tornado also affected Martin City and nearby
Holmes Park on May 23, 1946, destroying or damaging chicken coops, silos, a marketplace, barns, and homes. The tornado killed a couple and injured five people.
Fremont–Van Buren, Missouri A cyclic
supercell was likely responsible for this deadly, violent tornado, which probably formed over remote parts of the
Mark Twain National Forest. The tornado, possibly a member of a long-lived family, did little or no damage before Fremont. Entering town, the tornado rendered unusable all but seven structures, causing "F5-appearing" damage. Hardest hit were schools, businesses, and homes on the eastern side of Fremont, along and near the railroad; these were poorly built, so the tornado was rated F4, but F5 winds could have occurred. A three-story brick school was nearly leveled, and trees in town were partly debarked. In all, the tornado badly damaged or destroyed 50 homes in Fremont, while causing lesser damage to 31 others. The tornado also severely damaged a dozen other buildings in town, as well as eight small businesses. Past Fremont, the tornado remained intense, damaging structures in Van Buren at "near-F3" intensity. In Van Buren the tornado destroyed 25 homes and severely damaged 35 more. It also badly damaged or destroyed 91 other structures and caused significant damage to three small businesses. In all, it damaged about half of Van Buren. Its path may have been long. Six of the seven fatalities were at Fremont, where over 25% of the population was killed or injured. ==See also==