Mesoscale convective systems - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 297

Figure 5.24. Bookend vortices in a simulated squall line MCS. Horizontal cross section at 5 h
after initiation of storm-relative flow (vectors) at 2.5 km AGL in an environment of strong low-
level shear. Vectors plotted every other grid point, corresponding to a distance of 25m s 1
every two grid points). Rainwater field (solid lines) is contoured every 2 g kg 1 (fromWeisman,
1993).
Figure 5.25. Schematic representation of an idealized two-dimensional counter-rotating vortex
couplet showing the stronger flow (wind field depicted by vectors) induced in between the
vortices. Shading marks regions of constant vertical vorticity and unshaded areas have zero
vorticity. Dashed contours represent an approximate negative perturbation pressure field
consistent with the wind field. Locations of lowest pressure are denoted by an ''L'' (from
Weisman, 1993).