Van Leer, Kevin W., Brian F. Jewett, Robert B.
Wilhelmson, University of Illinois
With a goal of capturing
the mechanisms involved in the sensitive tornadogenesis process, this study
utilizes the WRF model to simulate the 22 May 2011 Joplin tornadic event. On this day, an EF-5 tornado was produced
in a low vertical shear environment, atypical for violent tornadoes of this
magnitude. This places an emphasis
on the investigation of alternate sources for low-level shear enhancement, such
as storm-mergers and boundary interactions. Simulations utilize NAM or RUC native grid initializations
and boundary conditions with multiple physics and nest placement combinations.
Current model runs at grid spacings of approximately 100 meters reveal
sensitive storm-scale processes, not only to the environment, but also to model
configurations. Vertical soundings
retrieved from vital times and locations in the real-data simulations provide
input for idealized runs and tests of resulting storm structure and behavior
due to varying shear and thermodynamic profiles. Further analysis of both types of simulations will focus on
identification of specific mechanisms for low-level shear enhancement in this
case and others with similar storm environments.