What is the direction of wind through a helicopters main rotor during autorotation?

During autorotation, the direction of wind through a helicopter's main rotor is upward relative to the rotor blades. As the helicopter descends, the airflow moves upward through the rotor system, allowing the blades to generate lift despite the loss of engine power. This upward airflow is crucial for maintaining rotor RPM and controlling descent during the autorotation process.