What occurs when cold air passes over a warm surface?

When cold air passes over a warm surface, it leads to the development of an advection thunderstorm. This type of thunderstorm occurs when warm, moist air is lifted, often as a result of being advected—moved horizontally—over a cooler surface, like a body of water or a land area that has not warmed up as much. The temperature contrast causes the air to rise, which can result in convection, ultimately leading to the formation of thunderstorms.

This process is particularly effective when the warm air is sufficiently moist and unstable, allowing for the development of convective clouds that can lead to thunderstorm activity. Advection thunderstorms typically occur in situations where warm, moist air flows over a cooler area, causing the warm air to rise due to buoyancy, fostering the conditions needed for thunderstorm generation.