On May 19, 1996, at 2115 central daylight time, an Air Tractor AT401, N1019X, operated by JDM, Inc., was substantially damaged when it nosed over during takeoff from a private airstrip in Letcher, South Dakota. The commercial pilot reported no injuries. Thunderstorms and severe winds were reported by witnesses. The 14 CFR Part 91 ferry flight was planned to Mitchell, South Dakota. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that he landed, following an aerial application flight, and observed lightning to the northwest of the airstrip and "it was apparent that possibly severe weather was approaching the field. The decision was made to ferry the empty aircraft...where hangar facilities are available." During the takeoff roll toward the south, the gust front from the approaching storm reached the field. The wind changed from calm to approximately 30 knots from the west. He wrote that he attempted to continue the takeoff but "was unable to attain flying speed and maintain directional control." The airplane departed the east side of the runway and nosed over. The pilot reported no preimpact mechanical malfunctions.