| Tornado outbreak|
| May 25–26, 1955|
| Flint–Worcester tornado outbreak, April 1956 tornado outbreak, 1953 Flint–Beecher tornado, 1899 New Richmond tornado, 1908 Dixie tornado outbreak|
The 1955 Great Plains tornado outbreak was a deadly tornado outbreak that struck the southern and central U.S Great Plains States on May 25–26, 1955. It produced at least 46 tornadoes across seven states including two F5 tornadoes in Blackwell, Oklahoma, and Udall, Kansas that caused most of the casualties. The outbreak killed 102 from three tornadoes while injuring hundreds more. Unusual electromagnetic activity was observed, including St. Elmo's fire.
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1955 Great Plains tornado outbreak Wikipedia
The Blackwell tornado formed in Noble County at around 9:00 PM CDT before crossing through the eastern portions of the Kay County town of Blackwell as an F5 wedge tornado. Then about 400 yd (0.23 mi) wide (Grazulis 1991), It claimed the lives of 20 people in Blackwell and injured over 200 before crossing into and dissipating over Cowley County, Kansas. Along with destroying nearly 200 homes, the tornado also demolished the town's main employers including the Acme Foundry and the Hazel Atlas Glass plant. 400 homes were destroyed or swept away, and 500 other homes were damaged. 60 businesses were also destroyed and the local hospital also sustained major damage. Most of the western half of the town was spared the worst of the damage.
30 minutes later, the same supercell that spawned the Blackwell tornado produced another violent and long-tracked tornado just east of the first tornado track near the Kansas/Oklahoma border. It proceeded northward across Sumner and Cowley Counties. The town of Udall was especially hard hit with F5 damage that included the disintegration of numerous structures and homes all across the town. Even the town's water tower was toppled. The funnel, about 1,300 yd (0.74 mi) wide, hit Udall at around 10:30 PM CDT. Half of the town's population was killed or injured. Numerous homes and businesses were destroyed, many of which were swept away. Vehicles were thrown hundreds of yards and mangled beyond recognition, including a pickup truck that was wrapped around a tree and stripped of everything but its frame and tires. The Udall public school building sustained major damage, with beams snapped and blown away. The tornado later dissipated after traveling over 50 mi (80 km) from the Oklahoma border to southeast of Wichita. This tornado was the deadliest in the state's history with 80 fatalities and over 200 injured.
In addition NWS officials confirmed an additional F2 tornado near Tonkawa which may have been either part of the Blackwell tornado or a satellite tornado. Other tornadoes in the region occurred on May 27 near the same region but did little damage. Among them were those produced by a thunderstorm which traveled through the Oklahoma City area, where it produced weak tornadoes with minimal damage in the towns of Norman and Chickasha.
Another deadly tornado occurred south of Woodward and at Cheyenne in Roger Mills County in southwestern Oklahoma, killing two people. This storm originated from the Texas Panhandle. The final tornado in the hardest-hit region occurred during the early morning hours of May 26 when a weak tornado occurred in Salisaw in Sequoyah near the Arkansas border.
Numerous tornadoes occurred across the Midwestern states from Arkansas to Illinois. The strongest tornado was located near the Little Rock area but no fatalities were reported with this tornado or any other on May 26.