Minnesota is one of several states in a Midwestern belt that experiences a weather phenomenon called "thundersnow" -- when lightning flares and thunder rumbles in the midst of a snowstorm. Meteorologists really don't know a lot about thundersnow, and that's why a University of Missouri researcher has just been awarded a half-million dollar grant from the National Science Foundation to find out more. Patrick Market has been studying thundersnow for the past four years. He says thunderclouds that form in the winter are much different from those we see in the summer.