Abstract
Experimental data and theory suggest that certain convection cell scale factors must be specified for correct interpretation of tornado simulations. The most important nondimensional number appears to be the ratio of convection cell depth (relating to height of vortex terminal region) to radius of the updraft. This scale factor has been ignored by most investigators, but it is especially important when comparing experimental results between two simulators or when relating simulator results to real tornadoes. Implications are discussed for possible cell geometry effects on tornadoes.