WHILE ON FINAL APPROACH FOR LANDING, THE PILOT REPORTED THAT THE FLIGHT ENCOUNTERED TURBULENCE AND A STRONG CROSSWIND. THE PILOT CONTINUED THE APPROACH UNTIL THE FLIGHT WAS ON SHORT FINAL AND APPROXIMATELY 50 TO 80 FEET AGL WHEN THE AIRPLANE SUDDENLY BANKED APPROXIMATELY 60 DEGREES TO THE LEFT. THE PILOT TRIED TO CORRECT WITH FULL OPPOSITE CONTROLS AND FULL POWER; HOWEVER, THE LEFT WING STRUCK THE GROUND. THE PILOT REGAINED CONTROL OF THE AIRPLANE AND INITIATED A GO-AROUND. THE PILOT CONTINUED THE GO-AROUND AND LANDED WITHOUT FURTHER INCIDENT.