Development of a Web-Based Tool to Forecast Wet-Bulb Globe Temperature for Populations Who Engage in Exertional Outdoor Activities

Individuals who engage in exertional activities during the warm season are vulnerable to heat illness, a disease that is entirely preventable when proper precautions are taken. The National Weather Service (NWS) currently utilizes the heat index as a measure of heat stress, issuing heat advisories and warnings when the index exceeds specified thresholds. Heat index, however, only accounts for the effects of air temperature and humidity on heat stress. Wet bulb globe temperature (WBGT), in addition to these variables, incorporates the effects of wind speed and solar radiation on heat stress. Consequently, an increasing number of state high school athletic associations are requiring the measurement of WBGT over athletic practice surfaces, such as turf, asphalt tennis courts, etc. Unfortunately, there is limited WBGT monitoring due to a lack of WBGT devices at weather stations and challenges in accurately estimating WBGT from standard meteorological variables. To address this need, the NOAA Southeast Regional Climate Center (SERCC) has partnered with the Carolinas Integrated Science and Assessments program (CISA) and the North Carolina State Climate Office to develop a web-based tool for forecasting WBGT across Central North Carolina. The publicly accessible tool provides hourly estimates of WBGT in a time series format using an algorithm that inputs meteorological variables from the National Digital Forecast Database (NDFD). The user can view WBGT forecasts over a 5-day time frame to make informed decisions about when to schedule exertional outdoor activities. In this talk, we will describe the methodology we employed to estimate WBGT, and we will compare it with other methods through a validation analysis. In addition, we will highlight changes we are making to the user interface in response to feedback garnered from a few high school athletic directors and trainers who used the tool this past summer. We plan to implement the new interface in time for the upcoming warm season and expand the domain of the model to the entire southeastern U.S.