On September 17, 1995, about 1500 central daylight time, a Schweizer SGU-2-22K, N2717Z, registered to a private owner, operating as a 14 CFR Part 91 instructional flight, collided with trees while attempting to land in the vicinity of Picayune, Mississippi. Visual meteorological conditions prevailed and no flight plan was filed. The glider was destroyed. The pilot-in- command (PIC) reported no injuries and student rated pilot reported minor injuries. The flight originated from Picayune, Mississippi, about 30 minutes before the accident. The PIC stated he obtained a weather briefing from Greenwood Flight Service Station before departing on the flight and was advised of thunderstorms in the area. While in the training area he observed a thunderstorm and believed it had matured and was dissipating. A short time later the thunderstorm started to develop and moved towards the Picayune Airport. He decided to return to the airport and make an approach to runway 23. The approach was terminated due to the thunderstorm reaching the airport first. He maneuvered the glider for an approach to a football field and was about 40 feet agl, when the glider encountered a strong wind gust and collided with the trees and the roof of a house.