FAA Commercial Pilot Airplane (CAX)WeatherHard
A pilot is flying at 10,000 feet MSL and encounters an area of continuous moderate to severe clear air turbulence (CAT). Which type of weather chart would provide the most useful information for anticipating this phenomenon?
- ASignificant Weather Prognostic Chart (High-Level)
- BWeather Depiction Chart
- CRadar Summary Chart
- DSurface Analysis Chart
Show answer & explanationAnswer & explanation
Correct answer: A. Significant Weather Prognostic Chart (High-Level)
Clear air turbulence (CAT) typically occurs at higher altitudes (above 15,000 feet MSL) and is not associated with clouds or thunderstorms. The High-Level Significant Weather Prognostic Chart (SIGWX PROG) forecasts conditions from FL250 to FL630, which often includes areas of CAT, tropopause heights, and jet stream locations, which are key indicators of CAT.
Why the other options are wrong
- B. Weather depiction charts show VFR/MVFR/IFR conditions and precipitation, not high-altitude CAT.
- C. Radar summary charts show precipitation areas and movement, not clear air turbulence.
- D. Surface analysis charts show surface weather and frontal positions, not upper-level turbulence.
High-Level SIGWX PROG Chart
The High-Level Significant Weather Prognostic Chart (SIGWX PROG) forecasts significant weather phenomena, including clear air turbulence, icing, and tropopause heights, for flight levels from 25,000 to 63,000 feet MSL.
- Forecasts for FL250 to FL630.
- Shows clear air turbulence (CAT) areas.
- Indicates jet stream locations.
- Displays tropopause heights and folds.
Memory trick: CAT's high flight: SIGWX PROG, day and night.