Q. At what temperature does lake-effect snow happen?
— Submitted by Mason Rather, sixth grade, Jefferson Middle School
A. Lake-effect precipitation is driven by large temperature differences between cold air flowing over warm lake water, says Scott Bachmeier, a research meteorologist at the Space Science and Engineering Center at UW-Madison. The amount of precipitation depends mainly on the size of the water-to-air temperature difference and how far the wind blows across the lake.