Mesoscale flows are substantially ageostrophic and nonhydrostatic and definitely three-dimensional. Nevertheless, the many resemblances suggest physical concepts which link these vortical flows. Here, we can only summarize the similarities due to space considerations . Figure 2 . Schematic plan view of a supercell storm at the surface.
Thick lines encompasses radar echo.
Ground relative streamlines are also shown. The hook echo is largely, if not totally, within the wrapping clear slot. Further, the tornado is often located near the edge of the rain free cumulonimbus base and wall cloud positioned between the wrapping clear slot downdraft and the intense updraft feeding the wall cloud. It is usually manifest as a band or narrow, very deep, slot of cloud free air wrapping around a center of strong rotation and, eventually the tornado. Over 20 years of storm intercept observations show that typically the slot wraps around the region where the tornado forms about five to 10 minutes prior to tornado formation.