Meteorology and Weather Decision-Making
What you must know
Know the standard atmosphere, lapse rates, and how stability affects cloud type and turbulence. Understand the formation of fronts (cold, warm, occluded, stationary) and the weather each brings. Learn METAR and TAF decoding, including wind, visibility, ceiling, and remarks. Recognize the hazards: icing, thunderstorms, wind shear, and low-level turbulence.
Traps
Questions test whether you can read a METAR's ceiling: it is the lowest broken or overcast layer, not the lowest scattered layer. A TAF is a forecast, not an observation; do not treat it as current weather. Freezing rain implies severe icing risk. Thunderstorms contain all hazards: hail, turbulence, wind shear, and lightning; avoid by at least 20 miles. Temperature/dewpoint spread near zero means fog or low clouds are likely.
Rule of thumb
For fog and low ceilings, watch the spread: if temperature and dewpoint are within 2°C, expect saturation and reduced visibility. For thunderstorm avoidance, use 20 miles as a planning buffer.
Worked example
METAR: wind 27015G25, visibility 3SM, ceiling BKN008, temp 12, dewpoint 11. Decode: wind from 270° at 15 kt gusting 25, 3 statute miles visibility, broken ceiling at 800 ft, spread 1°C. Expect low clouds and possible fog; plan an alternate and brief for a possible missed approach.