An ice storm is a type of winter storm characterized by freezing rain, also known as a glaze event or, in some parts of the United States, as a silver thaw. The formation of ice begins with a layer of above-freezing air above a layer of sub-freezing temperatures closer to the surface. Frozen precipitation melts to rain while falling into the warm air layer, and then begins to refreeze in the cold layer below. [from wikipedia]

The formation of ice begins with a layer of above-freezing air above a layer of sub-freezing temperatures closer to the surface.[from wikipedia]