event Fort Worth, Texas The thunderstorm that would eventually produce the infamous F3 tornado in Fort Worth developed from a cluster of storms that formed west of the city. At 4:38 p.m. CST (22:38 UTC), a severe thunderstorm warning was issued on the quickly organizing storm for Parker County. About an hour later, another severe thunderstorm warning was issued, this time for Tarrant County, as the storm continued to track eastward. Radar imagery showed that the supercell was rapidly organizing, developing a bounded weak echo region and hook echo—radar signatures that hint at a strong and potentially tornadic thunderstorm—in less than a half-hour. Radar also indicated that a broad mesocyclone had developed by around 6:00 p.m. CST (00:00 UTC), extending vertically through the entirety of the supercell. At around the same time, a wall cloud was spotted in association with the rotating thunderstorm while baseball-sized hail fell ahead of the rotation in northern Fort Worth along I-820. Winds from the downdraft of another small thunderstorm south of Fort Worth allowed the strengthening supercell to organize further. At 6:10 p.m. (00:10 UTC), a tornado warning was issued for Tarrant County, and accordingly emergency sirens were activated in the Fort Worth a minute later. The tornado touched down at 6:18 p.m. CST (00:18 UTC) near Castleberry High School northwest of downtown Fort Worth. Initially, the tornado lacked a condensation funnel, and could only be visually identified as dust swirls near the ground beneath the rotating wall cloud aloft; the tornado maintained this appearance for the first five minutes of its lifespan, after which a condensation funnel eventually developed. The first signs of damage occurred in the River Oaks area along SH 183 where metal roof panels were stripped off of a vacant fast food restaurant. After crossing the highway, the tornado inflicted sporadic F0 damage to an older residential area, breaking tree branches and causing some damage to outbuildings; a few chimneys were toppled off of homes. At the time, the tornado's damage path was only a few hundred feet wide. A roof of a home near Roberts Cut Off Road was partially removed, signifying the first instance of F1 damage. Several large and rotted trees were uprooted by the tornado's strong winds as it moved through the area. The tornado then passed directly over Castleberry High School, causing significant damage to the school's field house. Tornadic debris—including rooftop air conditioning units,