Rain and snow mixed and snow. Though no "official" criteria exist for the term, in the United Kingdom the term is not used when any significant accumulation of snow on the ground takes place. It is often used when the temperature of the ground surface is above , preventing accumulation from occurring even if the air temperature is marginally below ; but even then, the falling precipitation must generally be something other than exclusively snow. In the United States, wintry mix generally refers to a mixture of freezing rain, ice pellets, and snow. In contrast to the usage in the United Kingdom, in the
David Sleet David Sleet David A. Sleet is an American scientist recognized for championing the application of behavioral science to unintentional injury prevention and helping to establish injury prevention as a global public health concern. He has published hundreds of articles and book chapters and was co-editor of the Handbook of Injury and Violence Prevention.; Injury and Violence Prevention: Behavioral Science Theories; Derryberry’s Educating for Health; and the international prize-winning World Report on Road Traffic Injury Prevention. In 2016, Dr. Sleet retired from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia where he served as the Associate Director for