VORTEX2: A Study of Tornado and Tornadic Thunderstorm Dynamics through High-Resolution Simulation, Advanced Data Assimilation and Prediction

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

The Verification of Origins of Rotation in Tornadoes Experiment #2 (VORTEX 2) is a multi-scale investigation of factors that lead to tornadogenesis. VORTEX 2 is a follow on to VORTEX 1 whose field phase was conducted during the Spring of 1994 and 1995. The VORTEX 1 advanced knowledge of the kinematic structures of tornadic and nontornadic storms and provided some hints as to the sensitivity of the evolution of supercell storms and tornadogenesis to very fine spatial scale heterogeneity. The VORTEX 2 community intends to extend and build upon the results of VORTEX 1. One of the obstacles in furthering understanding of tornadoes is the lack of complete observations of the atmospheric state at a sufficiently high resolution. The field phase of VORTEX 2 will collect unprecedented observations at the scales of convective storms and tornadoes and of their environment. A team from the Center for Analysis and Prediction of Storms (CAPS) will participation in the VORTEX 2 field experiment and conduct research in four principal areas: 1) Generate real-time high resolution (1-2 km) storm-scale ensemble and deterministic forecasts; 2) Conduct ultra-high (down to few meters) resolution numerical simulation experiments for tornado cases for dynamic understanding and validation of conceptual models; 3) Study the impact of microphysical processes and their parameterizations on thunderstorm downdraft, cold pool, and gust front dynamics and their roles in tornadogenesis; 4) Assimilate routine and special observations into very-high resolution four dimensional data sets to advance understanding of dynamics as well as predictability at the thunderstorm through tornado scales and for studying the impact of special field data on NWP and initial condition sensitivities. Intellectual merit: The project is expected to contribute significantly to addressing many of the scientific questions concerning tornadogenesis and decay, tornadic thunderstorm dynamics and their interaction with storm environment, the role of microphysical processes within tornadic thunderstorms, and the predictability of tornadoes and tornadic thunderstorms. The knowledge gained will allow better assessment of the probability of tornadoes occurring in supercell thunderstorms and thus will lead to advances in forecasting tornado intensity and longevity. Broader Impacts: The research will directly address one of the most important goals of weather research -- to improve the ability to accurately predict intense hazardous weather. This project will expose graduate students and young post-doctoral scientists to a major scientific field experiment and give them hands-on experiences working with experimental data sets. It will provide much needed education and training for them in the increasingly important areas of advanced data assimilation and high-resolution simulation and NWP. The research findings will have a direct path to operations through the group's work with operational data assimilation systems and prediction models and through their participation in the NOAA Hazardous Weather Testbed (HWT) Spring Forecast Experiments. The latter exposes operational weather forecasters, as well as university scientists, to cutting-edge forecasting capabilities and products.