Commonly occurring infrasonic waves recorded during the winter months are believed to originate by means of aerodynamic source mechanisms. Acoustic power spectra of these commonly observed signals are compared to the power spectra one would observe from theoretical source mechanisms. From this comparison, the theoretical source mechanism believed responsible for production of the observed signals is thought to be isotropic turbulence in the lee of mountain peaks. Experimentally recorded signals and their power spectra are shown. Source regions of three signals are identified.