Meteorology
What you must know
Understand the atmosphere: ISA, lapse rates, pressure and altimetry, and QNH/QFE/QNE. Learn cloud types and formation, stability, and the difference between stable and unstable air. Study fronts: cold, warm, occluded, and stationary, with their associated weather and cloud sequences. Learn thunderstorms and their hazards: downbursts, microbursts, wind shear, hail, icing, and lightning. Study icing types (rime, clear, mixed) and their formation conditions. Know visibility, fog types (radiation, advection, frontal), and the METAR/TAF/SPECI codes, plus significant weather charts and SIGMET/AIRMET.
Traps
Questions test: QNH set on the subscale gives altitude above mean sea level; QNE gives flight level. Another trap: a cold front brings rapid passage, cumulonimbus, and a wind shift with a temperature drop, while a warm front brings steady rain and stratus. Also, wind shear is most dangerous on approach and take-off, and microbursts can produce a 30–50 kt loss of airspeed within seconds.
Worked example
A METAR shows "22012KT 9999 SCT030 24/18 Q1015". Decode: wind 220° at 12 kt, visibility 10 km or more, scattered cloud at 3000 ft, temperature 24 °C, dewpoint 18 °C, QNH 1015 hPa. Spread of 6 °C means a low risk of fog.
Rule of thumb
Temperature–dewpoint spread under 3 °C suggests fog or low cloud risk. A falling QNH with a wind shift signals a frontal passage.