Chinooks: The Warm Winds of Southern Alberta Explained

The "Snow Eater" Winds

Derived from the Indigenous term meaning "Chinook people," a Chinook wind is a meteorological phenomenon featuring warm, dry winds that descend the eastern slopes of the Rocky Mountains into southern Alberta. Known locally as the "Snow Eater," a Chinook can melt feet of snow in hours and raise temperatures by over 20°C in a single day.

How a Chinook Form

The process is driven by the orthographic lifting of moist air from the Pacific Ocean over the Rocky Mountains:

1. Moist Pacific winds hit the western slopes of the Rockies, rise, and cool, dumping heavy rain or snow.
2. As the air descends the eastern slopes toward Alberta, it is completely dry. As it drops in elevation, the atmospheric pressure increases, compressing the air and heating it rapidly.
3. This dry, warm air sweeps across southern Alberta (most notably Calgary, Lethbridge, and Pincher Creek) at high speeds, creating a dramatic arc of clouds in the sky known as the "Chinook Arch."