Oklahoma has a humid subtropical climate with frequent thunderstorms and occasional tornadoes. The state is home to major surface flows, including the Arkansas, Canadian, and Red Rivers. These rivers are subject to flooding during periods of heavy rainfall. Major reservoirs and dams, such as the Keystone Dam on the Arkansas River, help to manage flood control and provide water for agriculture and drinking water. Oklahoma's hydrology is influenced by its geology, which includes karst formations and oil and gas extraction. Watershed and snowpack data are not significant factors in Oklahoma's hydrology due to its low snowfall and lack of major mountain ranges.