What effect do rivers and lakes have on thunderstorm paths?
Once a thunderstorm begins to form, rivers and lakes do not influence the direction the storm moves. While there is no single wind direction that determines thunderstorm movement, there are two primary influences on the movement of thunderstorms: pushed along by the wind above, or by cooler air flowing out from underneath other storms. The winds in the troposphere, the lowest 5 or 6 miles of the atmosphere, play an important role in the determination of thunderstorm development and movement. Many thunderstorms move at the mean wind speed and direction of the lowest 5 miles of the atmosphere. Early in their formation, thunderstorms may be steered by winds closer to the ground. Once the storm develops, particularly well organized storms, the storm often moves in the direction of the winds in the middle troposphere. Often an outflow boundary, or a gust front, moves out ahead of the thunderstorm as a result of cooling of the air due to evaporation in the downdraft of the thunderstorm. New
