The motion of simulated convective storms as a function of basic environmental parameters

Results from an eight-dimensional parameter space numerical simulation study are examined to determine how storm motions vary within the different parts of the parameter space. Storm motions are examined for both the dominant right moving and left moving storms in the simulations. Motion of the mature right-movers is the subject of this paper.

It is found that variations in the altitude of maximum buoyancy have roughly half the impact that variations in the low-level vertical shear have, under the reasonable amounts of variation of the two parameters studied here, for paired experiments having all other key environmental variables held constant. Likewise, use of a cooler ambient environment having half the precipitable water content relative to a control simulation also causes a significant response in storm motion. Sensitivity to lifted condensation level changes is somewhat weaker. These results point to the importance of environmental factors that can enhance storm intensity and rotation, which play a key role in determining deviate motion. Traditional methods of forecasting storm motion based solely on hodograph shape thus need to be revised to account for the influence of these other thermodynamic aspects of the storm environment as well.