While inbound to the airport the pilot stated that he listened to the automated terminal information service, which indicated that the wind was from 290° at 11 kts with gusts to 20 kts. The pilot selected runway 35 for the landing, and to compensate for the wind, he added an extra 5 knots to the approach speed. After passing the runway threshold during the final approach, while about 20 feet above the runway surface, the airplane suddenly rolled to the right and the right wingtip contacted the ground. The pilot further described that he thought that the airplane had encountered a significant wind shear. He then leveled the wings and added power to abort the landing, but the airplane impacted the runway several seconds later. The airplane came to rest in the grass to the left of the runway and the airplane’s fuselage and right wing were substantially damaged during the accident sequence. The pilot stated that there were no preimpact mechanical malfunctions or failures of the airplane that would have precluded normal operation. A surface weather observation taken about 9 minutes before the accident reported wind from 310° at 12 kts, with gusts to 17 kts. The wind conditions reported during the hour preceding and the hour following the accident included similar gusting crosswind conditions, with some directional variability/shearing reported about 40 minutes before and 1 hour after the accident time.