Supercells - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 226

Figure 4.42. As for Figure 4.41, but from nonlinear dynamic perturbation pressure gradient
forces.
specific synoptic conditions is not well known, but must be related to the vertical
structure of jets (and via the thermal wind relation, to the horizontal temperature
gradient) and the temperature advection profile in the vertical. Both cold
advection (in which the geostrophic wind (vector) backs (i.e., turns in a counter-
clockwise direction) with height) and warm advection (in which the geostrophic
wind (vector) veers (i.e., turns in a clockwise direction) with height) situations may
each be associated with clockwise or counterclockwise-turning hodographs. Relat-
ing synoptic situations (as described by the structure of baroclinic waves) to
hodographs is an area in which little research has been done, though there have
been climatological analyses of hodographs with respect to the quadrant of surface
cyclones and anticyclones for each season.
In general, clockwise-turning hodographs favor cyclonically rotating, ''right-
moving'' (RM) supercells and counterclockwise-turning hodographs favor
anticyclonically rotating, ''left-moving'' (LM) supercells. The former are the
predominant type of supercell observed, while the latter are observed only on very
rare occasions ( Figure 6.38 ).