What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Upon touchdown, airplane swerved and drifted to the right, and the left wing came up. Pilot required full left aileron and left rudder, yet still departed runway off right side. Pilot's assumption was a brake or wheel lock-up at touchdown. However investigation revealed no evidence of this. During review of weather, it was noted that despite excellent VMC weather with calm winds, AWOS reported 90-degree crosswind at 8 gusting to 14 during a single observation, which was reported 8 minutes after the mishap. Tis condition was not forecast in any preceding TAF. This wind condition could fully explain the behavior of the airplane.
As the FAA filed it
UPON TOUCHDOWN, AIRPLANE SWERVED AND DRIFTED TO THE RIGHT, AND THE LEFT WING CAME UP. PILOT REQUIRED FULL LEFT AILERON AND LEFT RUDDER, YET STILL DEPARTED RUNWAY OFF RIGHT SIDE. PILOT'S ASSUMPTION WAS A BRAKE OR WHEEL LOCK-UP AT TOUCHDOWN. HOWEVER INVESTIGATION REVEALED NO EVIDENCE OF THIS. DURING REVIEW OF WEATHER, IT WAS NOTED THAT DESPITE EXCELLENT VMC WEATHER WITH CALM WINDS, AWOS REPORTED 90-DEGREE CROSSWIND AT 8 GUSTING TO 14 DURING A SINGLE OBSERVATION, WHICH WAS REPORTED 8 MINUTES AFTER THE MISHAP. TIS CONDITION WAS NOT FORECAST IN ANY PRECEDING TAF. THIS WIND CONDITION COULD FULLY EXPLAIN THE BEHAVIOR OF THE AIRPLANE.