Glider pilots in the Midwest know that thermal updrafts

Solution 25DQ Step 1: Dense,broken or overcast middle and high cloudiness shade the surface cutting off surface heating and convective thermals.on a generally warm bright day but with patchy middle or high cloudiness,cumulus may develop,but the thermals are few and weak. The high-level cloudiness may drift by in patches.thermals surge and wane as the cloudiness decreases and increases.never anticipate optimum thermal soaring when plugged by these mid and high-level clouds. Middle-level convective clouds develop in updrafts at and just below the cloud levels.they do not extend upward from the surface.if a sailplane can reach levels near the cloud bases.the problem is reaching the convective level.