Cold Fronts
If a cold air mass spills onto and overtakes a neighboring warm air mass, the leading edge of this cold air will be a cold front. When a cold front passes through, the weather becomes significantly colder and drier. It isn’t uncommon for air temperatures to drop 10 degrees Fahrenheit or more within an hour of a cold frontal passage. The weather map symbol for a cold front is a blue curved line with blue triangles. The triangles point in the direction the cold air is moving.