How is prevailing visibility defined?

Prevailing visibility is defined as the maximum visibility that is equaled or exceeded in 180 degrees or more of the horizon circle. This definition considers the conditions over a significant portion of the horizon, rather than just focusing on the visibility in all directions or at any specific moment.

This is important because weather can be highly variable, and assessing visibility based on a broader range provides a more accurate depiction of overall conditions. Instead of identifying a single point where visibility is at its maximum or averaging various locations, prevailing visibility takes into account the predominant weather conditions that impact the majority of the horizon, ensuring that the measurement reflects what most observers would experience.

In practical applications, this definition helps meteorologists, pilots, and other professionals make informed decisions based on the visibility conditions that are most relevant for numerous activities, such as flying or driving. This recognition of a significant area of visibility makes the definition practical and applicable in real-world scenarios where decisions are based on safety and operational functionality.