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How do mountains and large bodies of water affect local weather?

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Weather forecasting Doppler radars, such as this one operated by the U.S. National Weather Service at New Underwood, South Dakota, extract the Doppler frequency shift of the echo produced by a moving target by noting how much the frequency of the received signal differs from the frequency of the signal that was transmitted.

Mountains and large bodies of water significantly influence local weather by creating distinct temperature and pressure gradients that drive local wind systems and precipitation patterns.

Influence of Large Bodies of Water

Large bodies of water, such as oceans and lakes, possess a higher heat capacity than land, meaning they heat and cool more slowly. This differential heating creates local wind systems:12
* Sea Breezes: During the day, land warms faster than water, creating low pressure over the land. This draws cooler, denser air from the water toward the land.31
* Land Breezes: At night, the land cools more rapidly than the water, reversing the pressure gradient and causing air to flow from the land toward the water.41
* Climate Moderation: Water bodies can moderate regional climates, leading to cooler summers and warmer winters in surrounding areas.5

Influence of Mountains

Mountains affect weather through their physical relief and altitude:
* Local Winds: Differential heating of slopes generates valley breezes (upslope) during the day and mountain breezes (downslope) at night.31
* Orographic Precipitation: As moist air is forced upward over a mountain, it cools and forms clouds, often resulting in heavy precipitation on the windward side. The leeward side typically experiences a rain shadow, characterized by reduced precipitation.67
* Foehn Winds: As air descends the leeward side of a mountain, it undergoes adiabatic warming, often resulting in warm, dry conditions.1