As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE CREW REPORTED THAT DURING TAKEOFF ROTATION THE LEFT HAND ENGINE FAN VIBRATION WENT INTO AMBER RANGE. THE CREW DECLARED AN EMERGENCY AND DIVERTED. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. ON POST FLIGHT INSPECTION FOUND THE LEFT HAND INBOARD TIRE WAS MISSING TREAD.