Meteorology
The atmosphere
Understand the standard atmosphere, the lapse rate, pressure and density altitude, and how temperature and humidity affect aircraft performance. Learn the difference between QNH, QFE and QNE and when each is used. Know the global circulation, the Coriolis effect, and the formation of highs, lows, troughs and ridges.
Clouds and precipitation
Study the classification of clouds by height and shape, the difference between stable and unstable air, and the conditions that produce cumulonimbus. Know the hazards of icing (rime, clear, mixed), the conditions for carburettor icing, and the meaning of freezing rain as a severe icing indicator. Understand thunderstorm life cycle, microbursts, wind shear, and the rules for avoiding them.
Wind and visibility
Learn how surface friction turns and slows wind, the meaning of backing and veering, and the formation of sea breezes, mountain waves and katabatic flow. Understand fog types (radiation, advection, frontal, upslope) and the conditions for each. Know how to read a METAR and TAF, including the meaning of TEMPO, BECMG, and the trend groups.
Traps
The most common traps are misreading a METAR's wind (direction is true at some stations, magnetic at others, and variable means variable), confusing BECMG with TEMPO, and forgetting that QNH is pressure reduced to sea level.
Worked example
METAR wind 24015G25KT means wind from 240° at 15 kt gusting 25 kt. Crosswind component = wind speed × sin(angle). For a 30° offset at 20 kt: 20 × 0.5 = 10 kt crosswind. Rule of thumb: sin 30° = 0.5, sin 45° = 0.7, sin 60° = 0.9.