Upslope Fog
What is upslope fog?
Upslope fog forms when moist, stable air is pushed up a slope of rising terrain, like a mountain range. As the air rises it cools, reaching its saturation point and condensing into fog. Unlike some other fog types, upslope fog needs wind to keep the moist air flowing up the slope, and it can be quite dense and extend to high altitudes. Think of it as fog "climbing the hill"—it's common on the eastern slopes of the Rocky Mountains.
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