The hydrologic cycle begins with the evaporation of water from the surface of the ocean. As moist air is lifted, it cools and water vapor condenses to form clouds.
Moisture is transported around the globe until it returns to the surface as precipitation .
Groundwater either seeps its way to into the oceans, rivers, and streams, or is released back into the atmosphere through transpiration . The balance of water that remains on the earth's surface is runoff , which empties into lakes, rivers and streams and is carried back to the oceans, where the cycle begins again. Lake effect snowfall is good example of the hydrologic cycle at work. Below is a vertical cross-section summarizing the processes of the hydrologic cycle that contribute to the production of lake effect snow. Evaporation of warm surface water increases the amount of moisture in the colder, drier air flowing immediately above the lake surface.