Sleet has a slightly different process of forming. Like freezing rain, snow falls into a warmer-than-freezing layer and melts. The warm layer isn’t as pronounced all the way down to the surface.

For sleet to form, a snowflake will hit a brief pocket of warmer air, then refreeze and bounce on the ground. For freezing rain, a snowflake melts into a raindrop in a large layer of warm air and ...