1. A wind directed up a slope, often used to describe winds produced by processes larger in scale than the slope. Because this flow produces rising atmospheric motion, upslope winds experience cooling, increasing relative humidity, decreasing stability, and, if sufficient moisture is present, the formation of fog, clouds, and precipitation. 2. Flow directed up a mountain slope and driven by heating at the earth's surface under light larger-scale flow conditions; a component of the mountain–valley or mountain–plains wind systems; same as anabatic wind.