5.3
On tornadogenesis failure
Jeff Trapp, NOAA/NSSL and NCAR/MMM, Boulder, CO
One of the more compelling sets of observations obtained during VORTEX was that of nontornadic supercell storms that generated low-level mesocyclones and also possessed other qualitative characteristics typically equated with a storm capable of spawning a tornado. I consider these observations to represent "tornadogenesis failure" and have used them as the basis to conclude that the existence of a low-level mesocyclone is an insufficient condition for tornadogenesis; nontornadic low-level mesocyclones also have been documented recently by R. Wakimoto and collaborators. Since most previous studies have assumed tacitly that an explanation of low-level mesocyclogenesis suffices to explain tornadogenesis, this conclusion adds another layer of complexity that must be addressed by complete models of tornadogenesis. Arguably, this is one of the more unexpected results from VORTEX. During the symposium, I will discuss the philosophy of the tornadogenesis failure concept, its impact on forecasting and warning operations, and its implications on future tornadogenesis field research projects and numerical modeling studies.
Session 5, Current theories of tornadogenesis
Wednesday, 12 January 2000, 4:00 PM-5:30 PM
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