2004 Jeep Liberty

Twice I have experienced a strange noise. It sounded similar to a flat tire or if something was flopping around and hitting the wheel well or something. I think I could feel it through the floor as well. I stopped and inspected the undercarriage but nothing is obviously wrong, and the issue goes away after stopping. Both times this happened, the temps were in the teens. Haven't experienced it at warmer temps. Any thoughts?