FAA Pilot’s Handbook of Aeronautical Knowledge Chapter 12 Weather Theory
Introduction Weather is an important factor that influences aircraft performance and flying safety.
It is the state of the atmosphere at a given time and place with respect to variables, such as temperature (heat or cold), moisture (wetness or dryness), wind velocity (calm or storm), visibility (clearness or cloudiness), and barometric pressure (high or low).
The term “weather” can also apply to adverse or destructive atmospheric conditions, such as high winds.
This chapter explains basic weather theory and offers pilots background knowledge of weather principles.
It is designed to help them gain a good understanding of how weather affects daily flying activities.
Understanding the theories behind weather helps a pilot make sound weather decisions based on the reports and forecasts obtained from a Flight Service Station (FSS) weather specialist and other aviation weather services.
Be it a local flight or a long crosscountry flight, decisions based on weather can dramatically affect the safety of the flight.