Usually when we talk about uneven heating of the Earth's surface we are discussing convection. The uneven heating results in some of the atmosphere to be warmer than other parts and changes in volume and pressure which result in updrafts and can cause thunderstorms and other violent weather.
The cause of this is the reflectiveness of the surface of the Earth at that point (the albedo) and the angle that the sun's rays strike it at. A field covered with snow and ice is going to be much more reflective than a black top asphalt parking lot. As such the parking lot absorbs much more shortwave radiation from the sun and gets much warmer.
