Explanation:

These are downslope winds flowing from high elevations of mountains, plateaus, and hills down their slopes to the valleys or planes below. A katabatic wind originates from radiational cooling of air atop a plateau, a mountain, glacier, or even a hill. Since the density of air is inversely proportional to temperature, the air will flow downwards, warming approximately adiabatically as it descends. The temperature of the air depends on the temperature in the source region and the amount of descent.