Which term describes wind direction and speed as observed by a moving weather station?

• A. Apparent wind
• B. True wind
• C. Local wind
• D. Ground wind

Answer: (A)

Apparent wind is what a moving weather station actually measures. It’s the wind you feel and read on a moving boat because the vessel’s motion adds or subtracts from the true wind you’d experience if you were stationary. In other words, apparent wind is the combination (vector sum) of the true wind and the wind created by the boat’s own movement through the air. When the boat is stationary, apparent wind equals true wind; when you move into the wind, apparent wind increases, and when you move with the wind, it decreases. True wind describes what the wind would be relative to a stationary observer, not what a moving sensor reads. Local wind and ground wind aren’t the standard terms used here.