Meteorology for PPL: the 10 most tested topics in the exam

1. The atmosphere and the ISA

The International Standard Atmosphere (ISA) model underpins everything: temperature lapse rate (−2°C per 1000 ft to the tropopause), pressure, density and the relationships between them. Questions on pressure altimetry, density altitude and temperature deviation from ISA are guaranteed.

Key values to know: ISA sea level temperature +15°C and pressure 1013.25 hPa, tropopause at approximately 36,000 ft, and the lapse rate of 1.98°C per 1000 ft.

2. Pressure and altimetry

QNH, QFE, QNE and the use of the altimeter sub-scale are core knowledge. The classic trap is "cold temperature correction": in temperatures below ISA, the altimeter reads too high — you are flying lower than indicated. Remember: "From high to low, look out below."

3. Cloud and precipitation terminology

You need to know cloud classification (cumuliform vs. stratiform, high vs. low) and how clouds are reported in METARs (FEW, SCT, BKN, OVC with height in hundreds of feet). Cumulonimbus (CB) and Towering Cumulus (TCU) are special entries that always appear in exam questions.

4. Stability, instability and convection

Stable air = stratiform cloud, smooth flight; unstable air = cumuliform cloud, turbulence, hail. The concepts of dry adiabatic lapse rate (−3°C/1000 ft) versus the saturated adiabatic lapse rate (approx. −1.5°C/1000 ft) form the core of convection questions.

5. Upper wind versus surface wind

Above the friction layer, wind backs and increases with altitude (Buys Ballot's law). The relationship between high/low pressure systems and wind direction (NH: clockwise around high, anticlockwise around low) is frequently tested alongside chart reading questions.

6. Fog and visibility restrictions

Radiation fog, advection fog, and how they relate to temperature and dew point. A dew point spread (T−Td) of less than 3°C is a red flag for fog formation. METAR codes: BR (mist), FG (dense fog), HZ (haze), RA (rain).

7. Thunderstorms and CB activity

The three phases of a thunderstorm (cumulus, mature, dissipating), associated hazards (wind shear, hail, turbulence, icing) and how to identify them in a METAR (TS, VCTS, CB) are mandatory knowledge. Never, ever fly through a CB.

8. Icing

Carburetor icing, airframe icing (rime vs. glaze ice), and the conditions under which each forms (0°C to −20°C in visible moisture). METAR codes such as FZRA, FZDZ and BCFG are typical exam material. Always use carb heat in known icing conditions.

9. Fronts and weather development

Warm and cold fronts, occlusions and stationary fronts: their cloud sequences and precipitation patterns. The classic warm front progression is: cirrus → cirrostratus → altostratus → nimbostratus as it approaches. A cold front brings an abrupt weather change with CB activity.

10. European climatology and flying weather

Prevailing westerlies in Western Europe (Ferrel Cell), the role of the Icelandic Low and Azores High, seasonal patterns, and local phenomena such as the foehn (Alps) and mistral (Rhône valley) appear in case-study questions.

Tip: use the UP Aviation METAR/TAF decoder to read real weather reports daily and anchor the theory in practical experience.