The Blue Ridge Mountains act as a barrier to the flow of air from the Gulf of Mexico, forcing it to rise and cool, which causes the moisture in the air to condense and form clouds. These clouds then produce rain, which falls on the mountains and the surrounding areas. The proximity of the Atlantic Ocean also contributes to the high rainfall in this region, as moisture from the ocean is carried inland by the prevailing winds.
The combination of these factors creates a climate that is conducive to heavy rainfall, making the northeastern part of Georgia one of the wettest regions in the state.