TTU Ka-1 scanning the RFD region of a HP supercell southwest of Sterling City, TX, on 26 May 2014. © J. Dahl.

Welcome! My group's research efforts are focused on the dynamics of convective storms, including supercells and tornadogenesis. Although such storms have been studied for many decades, there are still gaping holes in our knowledge base. One of the questions my group focuses on is where the rotation that feeds the tornado originates from. Is it generated within the storm or is it imported from the environment of the storm? What role does surface friction play, and do the different contributions vary from case to case? To tackle these questions, we use a mix of idealized numerical simulations (see the animation below) as well we mobile platforms (such as TTU's Sticknet and the Ka-band radars). One particularly useful technique to analyze numerical-model simulations involves forward trajectories, allowing us to analyze the evolution of the rotation of individual air parcels.
Related research questions address the origin and the behavior of outflow surges that are known to facilitate tornadogenesis. The overarching goal of our research efforts is to understand the basic dynamics that drive severe thunderstorms. Such knowledge will allow us to (i) understand why certain environments are conducive to severe storms such as tornadic supercells and (ii) improve the diagnosis and prediction of environments supportive of tornadic thunderstorms. For more information about our research, see here.

I'm always looking for enthusiastic graduate students interested in joining our storm-dynamics group! If you have any questions about the program here at Texas Tech or about our research, please feel free to contact me!

Simulation of a supercell using the Bryan cloud model (CM1). Shown are the horizontal velocity vectors, updraft (solid contours), downdraft (dashed contours), and reflectivity (shaded) at 3375 m AGL.