How long are TAFs typically valid for international flights?

TAFs, or Terminal Aerodrome Forecasts, are specific weather forecasts issued for airports and other aerodromes, with a focus on safety for aviation operations. For international flights, TAFs are typically issued with a validity period of 24 to 30 hours. This duration allows for a comprehensive forecast that covers the time frame pilots need to make informed decisions about their flight plans, particularly for weather conditions that could influence their route and destination.

The reason for this typical validity is that weather can change rapidly, and a 24 to 30-hour forecast provides a balance between having enough information for flight planning and the dynamic nature of weather patterns. Forecasts beyond this period may not be as reliable, as they could be affected by various atmospheric changes.

The other options do not align with the standard practices for TAFs. While shorter forecasts might provide information for very short-term flights, they do not encompass the full range needed for international operations. Longer validity periods are generally not used because the accuracy of weather forecasts decreases significantly beyond this timeframe, which could lead to unsafe flight decisions if relying on outdated information.