On July 30, 2000, at 1430 central daylight time, an Aero-Tek, Inc., Zuni experimental glider, N6ZF, struck the ground short of runway 33 at the Garner Field Airport, near Uvalde, Texas, during the final approach when it encountered adverse weather conditions. The private pilot/owner was not injured, and the airplane sustained substantial damage. Visual meteorological conditions prevailed for the local flight; however, a thunderstorm moved north-south across the airport during the time of the accident. A flight plan was not filed for the 14 Code of Federal Regulations Part 91 local flight which departed the Garner Field Airport at 1400. The pilot reported that the glider encountered moderate to severe turbulence associated with the thunderstorm, while on final approach to runway 33. The pilot further stated that the glider lost altitude, and there was "insufficient remaining altitude" to reach the runway. He initiated an off field landing approximately 400 feet short of the runway. During the landing roll, the right wing contacted brush, and the airplane groundlooped. Structural damage occurred to the fuselage, tailboom, and the elevator. The right aileron and the seat sustained damage.