Tornado outbreak of May 19–22, 1957


From May 19–22, 1957, a tornado outbreak took place across the US Central Plains. A total of 59 tornadoes were reported from Colorado to the Mississippi Valley. The most destructive tornado of the severe weather event—likely part of a long-lived family—was rated as an F5, the highest level, and is often called the Ruskin Heights tornado, after the site of its worst damage, a suburb and housing development in southern Kansas City, Missouri. Additionally, a powerful F4 tornado virtually destroyed Fremont, Missouri, claiming seven lives, and an F3 tornado killed eight others in and near Belgrade, Missouri. A pair of F4s—one in Minnesota, the other in Kansas—also neared F5 intensity. In all, 59 people were killed during the outbreak, including 44 in the Ruskin Heights tornado.

Background

The outbreak coincided with elevated tornado activity: the period May 19–26 was one of the most intense to date, since the founding of the United States Weather Bureau. At 00:30 UTC on May 20, a mid-level jet stream bisected dew points of, coincident with a low-pressure area and warm front over southeastern Nebraska. Soundings and surface weather observations indicated a robust, unstable warm sector, showing 3,000 j/kg of surface-based convective available potential energy and the presence of strong wind shear. Favoring supercells, this setup led to the then largest one-day total of tornadoes in Weather Bureau history. At 17:00 UTC the Severe Local Storms Unit in Kansas City had already issued a severe weather watch, mentioning tornadoes, for the Kansas–Nebraska state line and its environs. Subsequent updates covered much of the eastern Great Plains, from the Green Country to southeastern Nebraska. Upon formation, severe thunderstorms traveled at up to, attended by extremely large hail.

Confirmed tornadoes

Several unconfirmed tornadoes were also reported:
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 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.

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.