In TAFs, what does "fog" refer to specifically?

In Terminal Aerodrome Forecasts (TAFs), "fog" is specifically defined as a phenomenon that reduces visibility to less than 1 kilometer. This definition aligns with standard meteorological terminology, which categorizes fog based on the significant reduction in visibility it causes, often resulting from the suspension of water droplets in the air near the ground.

Visibility reduced to less than 1 kilometer indicates a dense presence of moisture, impacting flight operations significantly. This classification is crucial for pilots and air traffic controllers, as it informs decisions related to takeoffs, landings, and overall flight safety in low-visibility conditions. Understanding this definition in the context of TAFs helps in interpreting the forecasts accurately, ensuring that aviation stakeholders can adequately prepare for the challenges posed by such weather conditions.