In the TAF from KOKC, when does the clear sky become overcast?

The correct choice indicates that the transition to overcast conditions starts at 2,000 feet during the specified forecast period. In this context, the information is valuable because it provides a clear, definitive altitude at which the weather conditions change from clear skies to overcast.

Forecasts like TAF (Terminal Aerodrome Forecast) are crucial for pilots as they guide pre-flight planning and in-flight decision-making. The TAF represents weather conditions expected at an airport over a period, detailing various elements such as sky conditions. In aviation, having precise information about the cloud cover is essential for flight safety, particularly regarding visibility and the ability to maneuver during landing and takeoff.

In this case, by stating that overcast conditions will occur at 2,000 feet, pilots can prepare for potential changes in their flight path or approach, ensuring they have the necessary altitude parameters for safe operations during the transition to less favorable conditions.

The other choices introduce lower altitudes such as 200 feet, which indicates a more severe situation that would likely affect flight operations critically, and reference probabilities which could cause uncertainty in planning. For effective and safe aviation operations, having a clear and concrete understanding of sky conditions is preferred over vague probabilities.