What is a warm front?

A warm front is defined as the leading edge of warm air that is replacing colder air. This phenomenon occurs when a mass of warm, moist air moves toward an area occupied by colder, denser air, causing the warm air to rise over the cold air due to its lighter density. As the warm air ascends, it cools, leading to cloud formation and precipitation, often characterized by overcast skies and gradual changes in weather.

Understanding the behavior of warm fronts is critical for pilots as they approach areas of differing air masses, as this can significantly impact flight conditions. The transition from colder air to warmer air brings about meteorological changes that affect visibility, turbulence, and overall flight safety.