The week of May 20–26, 1957, was the most prolific in terms of tornado activity recorded to date.[18] On May 20–21, an upper-level trough traversed the Central United States. As it did so, a significant tornado outbreak took place over portions of Kansas, Nebraska, Missouri, and Oklahoma. Cold upper air temperatures and marginal surface dew points produced severe weather across the southern and central Great Plains. On May 21, the vigorous shortwave trough, co-located with a deep surface low, produced a violent tornado in Minnesota, while additional tornadoes killed fifteen people in Missouri. At the time, a potent mid-level jet stream produced winds of 70 to 80 kn (81 to 92 mph; 130 to 150 km/h), providing ample wind shear for tornado-producing supercells.[15]
On May 22, surface weather analysis indicated another low-pressure area over southwestern Oklahoma. In attendance, a series of cold fronts affected western Texas and eastern New Mexico. During their passage, outflow from thunderstorms affected the warm sector, farther to the southeast. On May 23, dew points rose across western Texas, and temperatures reached 77 °F (25 °C) in the warm sector. By 06:00 UTC (1:00 a.m. CDT/midnight MDT) on May 24, dew points of 60 to 65 °F (16 to 18 °C) surged into southeastern New Mexico on both sides of a warm front. A new surface low-pressure area also developed over New Mexico. Nine hours later, lifted index values increased to -11, coincident with surface-based convective available potential energy (CAPE) values near 3,500 J/kg. Based on observations from weather stations, the first thunderstorms developed by 16:30 UTC (11:30 a.m. CDT/10:30 a.m. MDT).[15][19]
"FU" denotes unclassified but confirmed tornadoes.
In addition to these tornadoes, there were at least three unconfirmed events. One tornado, sighted around 11:17 a.m. CST (17:17 UTC), occurred 20 mi (32 km) northwest of Wildorado, Texas, and may have developed in Deaf Smith County. It remained over rural areas and inflicted no damage. Additionally, at least one undocumented tornado was reported southeast and east of Midland around 6:30–7:15 p.m. (00:30–01:15 UTC).[15] A brief tornado also may have touched down near Moore in the Oklahoma City metropolitan area, breaking tree branches and windows.[17] None of these tornadoes was officially recorded in the National Weather Service database.[4]
This long-tracked tornado family likely consisted of as many as six tornadoes, each of which generated narrow swaths of damage. It began west of Clovis and ended southeast of Bellview. Intermittent damage to farms occurred between Grier and Hollene, including the destruction of two barns.[16][21][22]
This long-lived tornado family traveled northeastward to a point near Bushland, west of Amarillo. After damaging an orchard and farmland near Bovina, the tornado lifted near Hub before reforming near Friona. Near Friona and Black, the tornado damaged several homes, and destroyed structures on eight different farms. Funnel clouds in the parent storm instigated traffic accidents in Hereford that injured some people.[23][22][16]
This strong tornado first struck Sudan, then lifted and touched down in Olton. The tornado destroyed a total of 77 homes in and near Olton, a number of which were sited on farms outside town. The southern section of Olton received the most severe damage. The tornado lofted a vehicle 1⁄2 mi (0.80 km) as well. Three injuries were attributed to the tornado.[24][16][15][25]
This strong, long-tracked tornado family impacted Tahoka, Wilson, Slaton, and Savage, damaging, destroying, or unroofing more than 120 structures. Two homes and two barns were also destroyed west and north of Ralls. The tornado eventually dissipated east of Cone. Tornado researcher Thomas P. Grazulis listed the total path length as being 50 mi (80 km) and classified the tornado as an F2. One injury occurred along the path.[16][15][26]
One home, located north of Cotton Center, was moved 100 ft (30 m) off its foundation and torn apart. Three homes were unroofed or destroyed near the end of the path, southwest of Plainview. Nine homes also sustained minor damage. Four funnel clouds were reported nearby. Grazulis listed this tornado as an F2.[16][15]
Houses, barns, and trailers were destroyed near Halfway. Several livestock died as well. The tornado formed from the same storm as the Olton tornado.[16][24]
In Lenorah, this tornado impacted five homes, one of which was destroyed. This was one of two or three tornadoes in a 30-mile-long (48 km) family. Grazulis listed this tornado as an F2. One injury occurred.[27][16]
Numerous funnel clouds and/or tornadoes were reported, but only one touchdown was confirmed. A tornado damaged or destroyed a mobile home and outbuildings near Yoder and south of Torrington.[24]
4 deaths – This large, violent tornado destroyed 12 homes, some of which were levelled. The swath of F4 damage occurred south of Lawton. One car was transported 100 yd (91 m); although the vehicle crashed in a pond, the driver was not injured. The tornado damaged or destroyed several farms as well, and numerous farm animals died in its path. Two couples died and five people sustained injuries.[29][16][30]
This damaging tornado family first destroyed a barn, then impacted an oil refinery in Wynnewood. Subsequently, the tornado wrecked four homes, a school, and many barns southeast of Pauls Valley. The tornado may have lifted until it encountered and destroyed frame buildings in Wanette. The tornado finally destroyed a barn northwest of Macomb before dissipating. Grazulis listed the tornado as an F3.[16][31]
A strong tornado struck the community of Denton, killed 100 turkeys, and destroyed a chicken coop, a barn, and a home. Several farms reported extensive damage, and 2-by-4-inch (51 by 102 mm) boards pierced a house as well. Additionally, a bus transporting 20 passengers was cast into a ditch, but none of the passengers was injured.[16][32]
A tornado caused minor damage in Quapaw and destroyed a derrick at a mine east of Picher. An EF4 tornado later hit the Picher area on May 10, 2008.[32]
This tornado splintered trees, destroyed television antennas, and badly damaged a mobile home in Duncan. Grazulis did not list this tornado as an F2 or stronger.[32][16]
A new school was partly unroofed and damage was extensive to buildings and trees. Two funnel clouds were seen. Grazulis did not list this tornado as an F2 or stronger.[28][16]
Near Allen, the tornado unroofed a home and destroyed a barn. Trees and outbuildings were prostrated near Atwood, and a number of farmsteads were damaged along the path. Grazulis listed this tornado as an F2.[16][28]
^All losses are in 1957 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.[5][6][7][8][9]
^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.[10][11] While the Fujita scale has been superseded by the Enhanced Fujita scale in the U.S. since February 1, 2007,[12]Canada utilized the old scale until April 1, 2013;[13] nations elsewhere, like the United Kingdom, apply other classifications such as the TORRO scale.[14]
^ abAll 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.
^ abPrior to 1994, only the average widths of tornado paths were officially listed.[20]
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 14 January 2021.
^Edwards, Roger (5 March 2015). "Enhanced F Scale for Tornado Damage". The Online Tornado FAQ (by Roger Edwards, SPC). Storm Prediction Center. Retrieved 25 February 2016.
^National Weather Service (May 2019). New Mexico Event Report: F2 Tornado. Storm Events Database (Report). National Centers for Environmental Information. Retrieved 20 November 2019.
^National Weather Service (May 2019). Texas Event Report: F4 Tornado. Storm Events Database (Report). National Centers for Environmental Information. Retrieved 21 November 2019.
^Dye, Lucius W. (May 1957). Written at Kansas City, Missouri. "Oklahoma – May 1957". Weather Summary. Climatological Data. Oklahoma. 66 (5). Asheville, North Carolina: National Climatic Data Center: 66.
