Chinook winds can warm a cold mountainside quickly as air sinks and compresses downhill.

The longer version

Air descending the lee side of a mountain range is compressed by the higher pressure below. Compression warms it, and because the air is now dry after losing moisture during the climb, it warms at a faster rate than it cooled on the way up.

The result is a mild, gusty wind that can raise temperatures sharply within hours and remove snow cover very quickly. Similar downslope winds occur on many ranges and carry different local names wherever mountains stand in the path of a moist airflow. They can arrive with little warning and bring strong gusts to the foothills below.

Where this entry sits

Clouds, wind, rain, and storms shape daily life in ways that most people barely notice. This collection explains snow, lightning, rainbows, the turning seasons, temperature, the instruments forecasters rely on, and scraps of old weather lore. The full list sits on the Weather and Climate page, where every entry is listed in order.