Residents across the St. Louis region, from St. Charles to Kirkwood, reported seeing lighting and hearing booming thunder during the region’s first winter storm on Saturday. The rare weather phenomenon of thundersnow only shows up during severe winter weather. Saturday’s storm, which caused hours-long traffic backups along Interstate 70 and Interstate 44, was apparently one such event. Here’s why thundersnow is so rare to experience. #news #weather #snow #Missouri | KSDK News