The outbreak was caused by an upper-level shortwave trough that moved northeastward from Mexico into the Southern Plains states during the nighttime the morning of May 15.

The Storm Prediction Center (SPC) in Norman, Oklahoma, a division of the National Weather Service, initially issued a slight risk of severe thunderstorms early that morning over northwestern Texas, for a threat of large hail and damaging winds.

[3] A low-pressure area associated with the trough moved over Oklahoma that day, producing light to moderate rainfall and non-severe thunderstorms across that state into parts of North Texas.

[5] Supercells broke out in parts of northwestern Texas during the late afternoon hours, one of which developed the first tornado of the day at 5:38 p.m., near Belcherville in Montague County.

[5] At 7:13 p.m. CDT, storm spotters reported a large tornado on the ground near Millsap in Parker County, which caused roof damage to several homes in the town.

Four additional tornadoes occurred near the Shreveport metropolitan area on May 16, two of which touched down near Waskom, Texas, and two in Caddo Parish near the towns of Greenwood and Stonewall, Louisiana.