What are Chinook winds?

Chinook winds are known as warm, dry, down-slope winds that rise over mountains and descend into the valleys on the leeward side, particularly along the front range of the Rocky Mountains. As these winds move down the mountain slopes, they undergo adiabatic warming, which increases their temperature and reduces humidity. This phenomenon can lead to significant temperature increases in a matter of hours, causing snow to melt rapidly in winter, which is one of the defining characteristics of Chinook winds.

In contrast, the other choices describe different types of winds or weather phenomena that do not align with the definition of Chinook winds. Cold and moist winds typically come from polar regions or bodies of water, which is not characteristic of the warm, dry nature of Chinook winds. High-velocity, snow-laden winds would refer to storm systems rather than the gentle, warming effect of Chinook winds. Lastly, winds that lead to heavy rainfall are typically associated with moist air masses rather than the dry descent of Chinook winds. Thus, the profile of Chinook winds distinctly highlights their warm, dry, and down-slope characteristics, making the correct choice clear.