VORTEX2 Science

VORTEX2 is designed to improve our understanding of tornadogenesis, which ultimately will better allow us to assess the likelihood of tornadoes in supercell (2007) thunderstorms and possibly even tornado intensity, longevity, and cyclic behavior. VORTEX2 is also expected to vastly improve our understanding of the range of tornado structures and the relationships between tornado structure and characteristics of the parent thunderstorm.

Relationship of VORTEX2 to national research priorities

The rationale for VORTEX2 closely mirrors current national and international research priorities. In addition to the rather obvious relevance of VORTEX2 toward improving severe weather warnings, the new knowledge produced by VORTEX2 may lead to advances in tornado damage mitigation and may even be of considerable interest to the climate change community, given the economic importance of extreme weather and the potential shifts in the frequency and geographical distribution of extreme events resulting from climate change. Furthermore, it is believed that storm-scale numerical weather prediction must play a prominent role in the National Weather Service (NWS) initiative to increase tornado warning lead time. VORTEX2 datasets should become a testbed for numerical storm-scale prediction experiments.

Scientific areas of focus

Tornadogenesis

• Role of downdrafts in tornadogenesis
• Sensitivity of tornadogenesis to microphysical and thermodynamic characteristics
• Role of vorticity maxima along gust fronts in tornadogenesis and/or maintenance
• Modes for the development of significant tornadoes in supercells

Near ground wind field in tornadoes

• Vertical, radial, and swirling velocity profiles
• Asymmetries
• Multiple vorticies
• Angular momentum budgets
• Relationship between damage and wind speed, acceleration, and duration

Relationships between supercell storms and their environments

• Interactions among storms that are/are not favorable for tornadogenesis
• Effects of environmental heterogeneity on supercells and tornadogenesis

Storm-scale numerical weather prediction

• Analysis and prediction of supercells, mesocyclones, and tornadoes
• Assessment of parameterization errors for storm-scale models and data assimilation methods for the storm scale
• Optimal use of observations
• Analysis and prediction of the pre-storm Mesoscale environment

Other research efforts related to V2 include damage surveying, photogrammetry, mobile disdrometry and numerical simulation efforts.

Impacts

V2 is expected to lead to further improvements in tornado warning skill. It is believed storm-scale numerical weather prediction must play a prominent role in the initiative to improve short-term forecasts of severe weather; multi-sensor and multi-scale V2 data sets will serve as a testbed for numerical storm-scale prediction experiments. V2 will better our understanding of the relationships between tornadoes, their parent convection and the larger scale environment. Better insight into these relationships is essential if the reliable long-term predictions are to be made of changes in the frequency and geographical distribution of tornadoes due to climate change. Quantification of the actual temporal and spatial distribution of winds impacting structures will enable better engineering standards to be developed. Lastly, VORTEX2 includes an innovative educational component in which students will participate in a series of scientific seminars presented in the field by the many participating severe storm expert principal investigators.