What effect do mountainous regions have on measuring precipitation? (orographic precipitation)
Wind flow up a mountain tends to enhance precipitation – when the air moves higher into the atmosphere it is cooled, which drops the saturation dew point, and therefore tends to make more moisture available. Wind blowing down the mountain does the opposite. If the atmosphere is sufficiently unstable, the lift provokes deep convection. But in less convective situations, the extra moisture is squeezed out in the lowest layers of the atmosphere, mostly as the entirely liquid “warm rain process”.