Define and identify obscuring phenomena.
List the sky coverage terms that define a ceiling.
Identify the parameters that define fog.
Identify the requirements for fog formation.
Identify the two main types of fog and how they form and dissipate.
Describe the aviation hazards of ash clouds.
1. Weather for Aircrews, AFH 11-203, Volume 1, Chapters 9, 10, 11, 12, and 16
2. DOD Flight Information Publication (En route) Flight Information Handbook, Section C
Review Chapter Five and answer the Study Questions.
TURBULENCE DEFINED AND CLASSIFIED
Turbulence is any irregular or disturbed flow in the atmosphere producing gusts and/or eddies.
Occurrences of turbulence are local in extent and transient in character. Although general
forecasts of turbulence are quite good, forecasting precise locations is difficult.
Turbulence intensity is classified using a subjective scale. Figure 5-1 contains the four intensity
levels and the three time descriptors used by aircrews when giving a Pilot Report (PIREP), which
details the in-flight weather. You can see how individual crewmembers of the same aircraft
might disagree on the degree of turbulence they encountered. Realize moderate turbulence for a
B-52 could be severe or extreme for a T-34.
Weather Hazards of Turbulence, Icing, Ceilings, Visibility, and Ash Clouds