Tornado and Flash Flood (TORFF) Warnings: Operational Challenges during Multiple Hazards (Invited Presentation)

Tornadoes and flash floods are among the most destructive and deadly weather hazards in the United States.  In some cases, the two hazards occur in the same location at the approximately the same time, which raises a series of meteorological, societal, and communication concerns. Meteorologically, tornadoes and flash floods are individually very challenging to accurately predict, and these difficulties can be amplified when forecasters are required to identify and anticipate situations in which both tornadoes and excessive rainfall will occur in a given location. When warnings for both tornadoes and flash floods are in effect for a given location (hereafter abbreviated as TORFF), the desired actions can be mutually exclusive:  a tornado warning urges the public to seek shelter on the lowest floor of a building, whereas a flash flood warning indicates the need to seek higher ground. In this presentation, the author will report on work conducted as part of the 2015 VORTEX Southeast initiative, which included participant observations and interviews conducted with NWS forecasters in the Southeast to examine operational challenges they encounter in preparing for, identifying, and issuing warnings in a TORFF context. This ethnographic research connects to physical science research conducted simultaneously by collaborators to understand ways to better identify and predict supercells that produce heavy precipitation and tornadoes in the Southeast versus more traditional low precipitation supercells common to the Plains.