CPL Meteorology study guide
CPL Meteorology · Work through your exam, one topic at a time.
Meteorology is one of the knowledge areas a commercial pilot must master before flying professionally, and the CPL Meteorology examination tests whether you can interpret the atmosphere as an operational system rather than a list of definitions. The subject is aimed at candidates working toward a Commercial Pilot Licence, whether through an integrated course or modular study alongside other ATPL-level theory subjects. The CPL Meteorology study guide has 9 sections and about 2,527 words.
01The Atmosphere: Composition, Structure and Standard Atmosphere
The atmosphere is a mechanical mixture of gases: about 78% nitrogen, 21% oxygen and 1% argon, with variable water vapour (0–4%), carbon dioxide and traces of others. Candidates must separate the permanent gases from the variable ones.
307 words, about 2 min02Temperature, Pressure, Density and Their Altimetry Implications
Temperature, pressure and density are linked through the gas law and the hydrostatic equation. Density falls with altitude, with rising temperature (at constant pressure) and with rising humidity.
319 words, about 2 min03Moisture, Humidity and Atmospheric Stability
Candidates must know the difference between relative humidity (actual vapour content relative to saturation at that temperature) and dewpoint (the temperature to which air must cool to saturate). Dewpoint depression (temperature minus dewpoint) measures how close the air is to saturation.
260 words, about 1 min04Clouds, Precipitation and Fog
Clouds are classified by height and form. High cloud: cirrus, cirrostratus, cirrocumulus.
263 words, about 1 min05Air Masses, Fronts and Synoptic Weather Systems
Air masses take the characteristics of their source region: continental (dry) or maritime (moist), tropical (warm) or polar (cold). Classifications include mT, cP, mP, cT.
291 words, about 1 min06Wind: Global, Local and Upper-Level Circulation
Heating differences drive the general circulation. Trade winds blow from the subtropical highs toward the equatorial trough, deflected by the Coriolis force (right in the Northern Hemisphere).
275 words, about 1 min07Thunderstorms, Icing, Turbulence and Other Aviation Hazards
A thunderstorm requires three ingredients: sufficient moisture, conditional instability and a lifting trigger. Stages are cumulus (updrafts), mature (updrafts, downdrafts, rain, lightning, hail, gust front) and dissipating (downdrafts dominate).
251 words, about 1 min08Meteorological Observations, Reports and Forecast Products
Candidates must decode METAR and SPECI. Key groups: wind (direction/speed/gusts, VRB), visibility (metres), runway visual range (RVR), present weather (intensity, descriptor, precipitation, obscuration), cloud (amount FEW/SCT/BKN/OVC and height in hundreds of feet), temperature/dewpoint, QNH, and trend.
262 words, about 1 min09Weather Charts, Briefings and Flight Planning Application
Candidates must interpret surface synoptic charts (isobars, fronts, highs, lows, troughs), significant weather charts (SIGWX), upper-wind and temperature charts, and prognostic charts. On a surface chart, closely spaced isobars mean strong wind; a tight gradient near a front signals a squall line.
299 words, about 1 min