In addition to the standard briefing, what additional information should be asked to evaluate soaring conditions?

• A. The upper soundings to determine the thermal index at all soaring levels
• B. Current wind speed at the surface
• C. Nearest weather radar image
• D. Qualitative cloud observations from the pilot

Answer: (A)

Understanding how air stability and lift change with height is crucial for predicting soaring. An upper-air sounding provides a vertical profile of temperature, dew point, and wind with height, letting you assess stability at the altitudes you’ll fly and estimate the thermal index for each level. With that information, you can forecast where thermals will form, how high they’ll carry you, and where climbs may weaken or stop. Surface wind alone tells you conditions at the ground, not how the air behaves aloft. Radar shows precipitation and storms but doesn’t quantify lift potential in the mid to upper levels. Pilot cloud observations are useful but subjective and only reflect conditions at your current altitude, not a complete vertical picture. So obtaining upper-air sounding data to determine the thermal index across soaring levels provides the most direct, useful basis for evaluating soaring conditions.