As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PITCH OSCILLATIONS, REPO FLIGHT FROM GLH TO MSP CREW ENCOUNTERED LIGHT TO MODERATE TURBULENCE ON CLIMBOUT. THE AIRCRAFT HAD 2 EVENTS OF SEVERE PITCH OSCILLATIONS ABOUT 15 MINUTES INTO THE FLIGHT BETWEEN 24,000 TO 31,000, LIGHT RIME ICE PROTECTION ON. CREW PERFORMED MEMORY ITEMS AND FOLLOWED THE CHECKLIST. CREW DECLARED AN EMERGENCY AND DIVERTED TO MEM. NO FURTHER INFORMATION AT THIS TIME.