Definition - What does Lake Effect mean?
A lake effect is an weather change triggered by lakes or other similar large bodies of water that causes temperature changes in wine growing areas. Water has a specific heat capacity, so water heats up and cools down slower than land. This property of water causes cool breezes to blow along the shores of the lake during the summer through thermal convection. During fall, the warm air above the water body flows onshore creating a warmer environment, extending the grape growing season.
WineFrog explains Lake Effect
The lake effect also protects roots of the vine as it helps insulate them and protects them from freezing temperatures. The Lake effect is one of the many factors that affect the quality of wine through the vineyard. Climate and topography are among the most important factors that alter the character of any wine. The extended growing season triggered by the lake effect helps further ripen the grapes.
The lake effect and lake effect snow are commonly associated. When the water is still warm even after the harvest is over, the cold dry air passing over the water body picks up moisture and is known to help create lake effect snow. As a result, the vines of the grapes are insulated and are protected from freezing temperatures, due to the early snowfalls.