Self-test

Self-test Subject 050 Meteorology

This self-test covers key terms and application questions from Subject 050. Answers at the end of the page.

Atmosphere

1. What are pressure, temperature, and density in the ISA at mean sea level?
2. Which altitude range defines the troposphere in mid-latitudes per ISA?
3. What does "ISA + 15" mean?

Wind

4. Which two forces balance in geostrophic equilibrium?
5. In the Northern Hemisphere: wind is from 270°. Where is the low?
6. How does friction change the surface wind in direction and speed compared to the geostrophic wind?

Thermodynamics

7. What is the dry adiabatic lapse rate (in °C/1000 ft)?
8. With a spread (T − Td) of 8 °C: approximately how high is the cumulus cloud base (AGL)?
9. Condition "ELR < SALR": is the atmosphere stable or unstable?

Fronts and air masses

10. Which cloud sequence is observed ahead of a warm front?
11. How does the wind change at a cold-front passage in NH?
12. Which air mass is "mT"?

Icing

13. Which OAT range is most critical for airframe icing?
14. What distinguishes clear ice from rime ice?
15. Which anti-icing mechanism uses glycol?

Thunderstorms

16. How long does a single cell typically last?
17. In which stage is the cell most dangerous?
18. Minimum lateral distance to strong CB (FAA recommendation)?

Turbulence / LLWS

19. With Δn > 1.0 g: which turbulence level?
20. What is the rule of thumb for the microburst diameter?
21. When to pull to the stick-shaker during a microburst?

Met products

22. How often is a METAR issued?
23. What is the validity of a standard SIGMET?
24. What does "BECMG" mean in a TAF?
25. What units is the wind speed given in on WINTEM?

Altimetry

26. With OAT = ISA − 20 and 1000 ft above the reference point: how large is the cold-temperature correction?

Answers

1. 1013.25 hPa, 15 °C, 1.225 kg/m³.
2. 0–11 km (0–36,089 ft) in mid-latitudes.
3. Actual temperature is 15 °C warmer than ISA at that altitude.
4. Pressure gradient force and Coriolis force.
5. In the south (back to the wind, low on the left).
6. Wind turns toward the low (~30° over land, ~10° over sea), speed reduced by 30–50 %.
7. 9.8 °C/km ≈ 3 °C / 1000 ft.
8. ≈ 3200 ft (400 ft × 8 K).
9. Stable.
10. Cirrus → cirrostratus → altostratus → nimbostratus → stratus.
11. Veering to the right, temperature drop, pressure rise.
12. Maritime tropical, warm and moist.
13. 0 °C to −10 °C.
14. Clear ice: large drops, slow freezing, glassy; rime ice: small drops, instant freezing, milky.
15. TKS (Tracerite system).
16. 30–60 min.
17. Mature stage.
18. 20 NM (FAA AC 00-6B).
19. Severe.
20. < 4 km / 2.5 NM (Fujita).
21. At the first significant speed loss after the headwind phase, immediate full throttle, pitch to stick-shaker.
22. Every 30 minutes (HH+20, HH+50 typical internationally); SPECI in between for significant changes.
23. 4 hours (6 for TC/VA).
24. "Becoming": gradual, persistent transition.
25. Knots (kt).
26. 4 ft × 20 × 1 = 80 ft correction.