What are the wind and temperature reported by a pilot at 12,000 feet MSL?

At an altitude of 12,000 feet MSL, pilots must report both wind direction and velocity, along with temperature. The correct answer highlights that the wind is coming from 90 degrees at 21 knots, which indicates a wind blowing from the east, contributing to understanding the overall atmospheric conditions at that altitude.

The temperature of -9 degrees Celsius corresponds with typical temperature profiles experienced at a higher altitude. This detail is critical because it helps gauge the potential for weather phenomena such as icing, which can occur at these lower temperatures.

Wind direction is measured in degrees from true north, meaning a wind from 90 degrees indicates easterly winds, which can impact flight paths, takeoff, and landing procedures. Understanding both wind and temperature at altitude is essential for flight safety and effective navigation.