Turbulent flow that impacts aviation can be caused by several different factors and can occur at both low and high-levels in the atmosphere. This lesson focuses on forecasting mountain wave turbulence. Its methodology relies on the spatial and temporal distribution of winds, stability, and clouds to forecast and verify mountain wave turbulence. Analyzed forecast products include NWP charts, cross sections and soundings, satellite imagery, RAOBs, PIREPS, and graphical turbulence guidance (GTG). The lesson is targeted for aviation forecasters at the U.S. National Weather Service (NWS). The module briefly reviews background concepts, but largely relies on the COMET lesson Mountain Waves and Downslope Winds for prerequisite conceptual material.