Lake-effect snow is as big as a weather changer can be, especially white-out lake-effect bands. Lake-effect snows only occur in particular regions called snow belts, thus the residents in these areas are typically well versed on the consequences of living in the snow belt. Visitors or new residents to these regions are often in for a shock when a winter in these regions is experienced.

Lake-effect snow occurs due to very cold air picking up moisture from a huge lake and then depositing that moisture on and near the lakeshore downwind of the wind direction. The lake supplies a continuous supply of moisture. Moisture is often a limiting factor in snow events as a whole (non lake-effect events). However, in a lake-effect situation, the almost unlimited moisture can produce huge snowfalls and very heavy snow rates. A long fetch over the relative warm waters of a great lake can bring a continuous supply of moisture that can be uplifted and deposited as heavy snow in lake belt regions.

The weather can go from cold but nice to dangerous in a matter of minutes or a couple miles in a lake-effect event. It can be impossible to see while traveling in the heavy snow bands. The snow can accumulate in feet which make snow removal more challenging. One of the biggest weather changers that can be witnessed is traveling into a lake-effect snow band or observing one move in.