Tornado Warning Behavior and Decision Making in National Weather Service Forecast Offices

It is recognized that a number of scientific tools are available for National Weather Service (NWS) forecasters to aid tornado warning decision making, one of the primary responsibilities of the agency. Some of these tools are based on remote sensing technology, such as Doppler Radar and Geostationary Satellites. Others tools are available to help speed the process of composing and disseminating tornado warnings.

Despite all of our scientific advances, tornado warnings are still not perfect. Verification statistics, including scores like Probability of Detection (POD), False Alarm Rate (FAR), and Critical Success Index (CSI) are statistics to help determine how well the NWS is doing with its tornado warning program. However, none of those statistics include a measure of how human factors influence the decision process for tornado warnings. Some of those factors are from operational environment and culture in a forecast office, including increased workload, office team support, shifting responsibilities, etc. Other factors are from external sources, such as the perceived danger to loved ones during a tornado event, or personal events that are currently effecting an employee.

To make a first attempt at understanding those human, non-physical science factors, an extensive survey was undertaken of NWS warning forecasters. The survey covered a number of topics the authors deem as important to the tornado warning decision process, with questions on basic demographics, experience level of forecasters, knowledge among those forecasters of Government Performance and Results Act (GPRA) goals of the agency, and a host of human factors, such as the forecasters’ interaction with others on the operational floor during the tornado warning decision process, as well as their overall comfort with the task and responsibility when charged with making the tornado warning decision.

The results from the survey will be presented, along with recommended best practices. Many of the best practices will be taken by comparing survey results from offices that have performed in the top 15% based on the GPRA metrics.