Prior to VORTEX-USA, a limited number of studies on how terrain impacted tornado formation and behavior had been conducted, largely on individual cases. These studies had primarily focused on the channeling of low-level flow up valleys, including the Hudson River Valley in eastern NY and the Central Valley of CA, and how this channeling could lead to enhanced moisture transport and low-level wind shear, ultimately increasing the likelihood of a storm producing a tornado. The VORTEX-USA program has significantly expanded our understanding of how terrain can impact tornado behavior and the likelihood of tornado formation. Projects funded through VORTEX-USA have identified previously unknown influences that terrain can have on the low-level environmental wind shear and stability profiles, potentially leading to increased incidences of tornadogenesis linked to underlying terrain features. Other VORTEX-USA projects have used high-resolution simulations to understand how terrain can influence tornado intensity and track evolution. This work has invigorated community-wide efforts toward more fully understanding terrain influences on severe storm and tornado behavior.
