Final answer:
Freezing rain and sleet often occur with cold fronts when warm, moist air is forced to rise rapidly and condenses into ice pellets or freezing rain.
Step-by-step explanation:
Freezing rain and sleet often occur with cold fronts. When a cold front moves into an area, it forces warm, moist air to rise rapidly. As the air rises and cools, the water vapor condenses and freezes into ice pellets or freezing rain. This can happen when the temperature is near or slightly below freezing.