For clouds to form, air needs to rise, either on its own by becoming less
dense than surrounding air or by being lifted by denser air impinging upon it.
On a sunny day, land heats up quickly compared to the lakes. As air near the
surface is heated, water vapor rises, cools and condenses into clouds. Over
water, this same rapid heating of air does not occur. In fact, the cooler air
over water typically moves inland in the form of a sea breeze to replace the
air that has been rising over land. This influx of denser air, called a sea
breeze front, enhances the lifting that occurs over land and can lead to the
formation of more clouds.
