1.   By now I was well under the cloud base and had some idea of horizontal reference and applied maximum boost and revs to regain height.

2.   As air pressure lowers in the spinning column, condensation occurs just below cloud base, revealing a funnel cloud.

3.   As pressure lowers in the column, condensation occurs just below cloud base, revealing a funnel cloud.

4.   As pressure lowers in the spinning column, condensation occurs just below cloud base, revealing the funnel cloud.

5.   As pressure lowers in the spinning column, condensation occurs just below cloud base, revealing a funnel cloud.

6.   A few funnel clouds will ominously dip down just below cloud base while, in isolated instances, tornadoes and waterspouts may touch down for brief periods.

7.   A waterspout then becomes visible as a funnel-shaped cloud lowers from the existing cloud base.

8.   Meanwhile, ominous funnel clouds hovered just below cloud base near Lake Forest.

9.   Ominous but innocuous funnel clouds hovered below cloud bases over parts of Illinois Monday evening.

10.   The key to a heat burst lies in the profile of temperature below cloud base.