Meteorology
Meteorology tests the atmosphere, pressure systems, wind, clouds, fronts, icing, thunderstorms and the interpretation of METAR, TAF, SIGMET and wind-shear warnings.
Core concepts
- QNH is the pressure setting that makes the altimeter read elevation; QFE reads height above a reference.
- A temperature/dewpoint spread indicates the likelihood of cloud; the lifting condensation level is roughly 125 m per °C of spread.
- Frontal lifting produces widespread cloud and precipitation; convective clouds produce turbulence, icing, hail and microbursts.
- Freezing rain implies supercooled water and severe airframe icing.
Worked example
Surface temperature 20°C, dewpoint 12°C. Spread = 8°C. Estimated convective cloud base ≈ 8 × 125 m = 1,000 m AGL. If the forecast shows further heating and moisture, expect cumulus build-up and possible showers; plan an alternate route or altitude with clear air.
Traps
- Confusing QNH with QFE.
- Treating a TAF as current observation; check issue and validity times.
- Underestimating icing in freezing rain or in cumulus below 0°C.
- Ignoring wind shear and microburst reports on final approach.
- Assuming clear air means no turbulence near a jet stream.