Frontal rainoccurs when two air masses with different temperatures and humidity levels meet. When a warm air mass and a cold air mass meet, the warm air is forced to rise over the denser cold air. As the warm air rises, it cools and the water vapor it contains condenses into clouds, eventually leading to precipitation in the form of rain.
Frontal rain typically occurs at the boundary between two air masses, known as a front. There are two main types of fronts that can lead to frontal rain:
Cold Front: When a cold air mass advances and pushes under a warm air mass, the warm air is forced to rise rapidly. As it rises, it cools and forms clouds, leading to heavy rain showers.
Warm Front: When a warm air mass advances and rises over a cold air mass, the warm air gradually cools as it ascends, leading to the formation of clouds and precipitation over a larger area, often resulting in more prolonged periods of light to moderate rain.