April 16, 2021 - 3:00 pm
April 16, 2021 - 4:00 pm
CategoriesConvective Meteorology (Mesoscale Dynamics)
Convective Meteorology (Mesoscale Dynamics) Seminar
Vorticity Characteristics During Tornadogenesis in a High Resolution, Violently Tornadic Supercell Simulation
Friday, April 16th
Join Google Meet:
It’s no stretch to say that the exact process of tornadogenesis remains somewhat of a mystery. Having the “tornado-in-a-bottle” scenario that we have here provides a unique look at the process. It may answer questions in some ways, but we have found that it more often leads to new questions. Nonetheless, one of the many questions we obviously have is how does the tornado form in these situations? What does the process look like? This presentation will involve mostly 3D volume renderings of vorticity during the genesis phase of the storm. Some quantitative analysis of near-updraft characteristics will also be shown. A notable observation from this simulation is the fact that we have yet to identify an obvious trigger mechanism for the tornado. The rear-flank downdraft and the streamwise vorticity current both play an important role in tilting of horizontal vorticity into the vertical. However, they do this in concert with significant increases in near-ground vertical acceleration and Vorticity an overall lowering of the low-level updraft base. This also results in significant increases in storm-relative horizontal winds. In this particular simulation, the tornado forms through a vertical vortex merger process that appears to be the result of all of these events working together. Exactly what drives these significant increases in the updraft strength moments prior to the tornado is yet to be determined and is one topic of future work. One important consideration for this particular study is the fact that this simulation was initialized in an upper-echelon environment, and it produces a very high-end EF-5 tornado. The process of forming a long-lived, violent tornado may not necessarily be the same as a weaker, short-lived tornado.