A stability warning system for a tree feller-buncher includes a first inertial measurement unit configured to measure an orientation of an undercarriage of the tree feller-buncher carrying at least one track, a second inertial measurement unit configured to measure an orientation of a boom coupled to the turntable, and a felling head operably connected to the boom. A controller is operable to estimate a center of gravity of the tree feller-buncher based on the measured orientation of the undercarriage and the measured orientation of the boom.