What values are used for Winds Aloft Forecasts?

• A. True direction and knots
• B. Magnetic direction and mph
• C. True direction and mph
• D. Magnetic direction and knots

Answer: (A)

Winds aloft forecasts provide wind direction as true direction and wind speed in knots. This standardization avoids the variability of magnetic variation, which changes with location and over time, making magnetic directions impractical for planning across routes. Using knots is consistent with other aviation speed measurements and keeps calculations straightforward when determining groundspeed from a known true course. So a forecast value indicates the wind from a given true direction, at a certain speed in knots.