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Weather theoryQuestion 349 of 934

Which three ingredients must be present for a thunderstorm to form?

  1. Enough water vapor, a stable lapse rate, and a temperature inversion
  2. Dry air, an unstable lapse rate, and an initial lifting action
  3. Enough water vapor, an unstable lapse rate, and initial lifting
  4. Cold air, calm winds, and a stable lapse rate near the ground
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Correct answer: Enough water vapor, an unstable lapse rate, and initial lifting

Fronts, converging winds, or surface heating can supply the lifting action.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 12: Weather Theory — Thunderstorms, page 307

Practice weather theory

Questions last reviewed: 18 October 2026