Supercells - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 190

Figure 4.14g. Soundings on days when there were tornado outbreaks (see Figure 4.14f ).
Sounding at (top) Norman, OK on May 24, 2011 at 18:00 utc and (bottom) at Birmingham,
AL on April 27, 2011 at 18:00 utc . Soundings may vary substantially in space and time near
tornadic supercells. The most representative soundings may be those released on days when
widespread, long-lived, tornadic supercells occur, such as those shown here. In both, about
three hours before tornadic supercells were mature, there was a moist boundary layer, topped
by a capping inversion. In the case of the Birmingham sounding, the cap is elevated, indicative
of some lifting having occurred. In both some CIN must have been overcome for low-level air
to reach its LFC. In each, the hodograph (insets at the upper left) is ''long'' and there is a bend
in the vertical shear vector near the altitude of the interface between the moist boundary layer
and the region above (soundings from NCAR/EOL).