Forecasting the Wet-Bulb Globe Temperature: A Web-Based Tool Designed for Populations Who Are Vulnerable to Heat-Related Illnesses

Populations who engage in exertional activities during the warm season are especially vulnerable to heat-related illnesses (e.g. heat cramps, heat exhaustion, and heat stroke). Fortunately, these illnesses are entirely preventable when proper precautions are taken to protect individuals exposed to heat stress. Heat stress is generally determined through meteorological parameters. The National Weather Service (NWS) currently uses the heat index as a measure of heat stress to issue advisories and warnings when the index exceeds certain thresholds. The heat index, however, only accounts for the effects of air temperature and humidity on heat stress. The wet bulb globe temperature (WBGT) takes into account the effects of wind speed and solar radiation on heat stress, as well as those variables defined by the heat index. An increasing number of state high school athletic associations are requiring the measurement of WBGT in order to protect student athletes from heat stress. Unfortunately, there is limited WBGT monitoring due to a lack of WBGT measuring devices and the unavailability of forecasts of WBGT. 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. 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 describe the methodology employed to estimate WBGT and the challenges of estimating WBGT for different land cover types and practice surfaces. In addition, we highlight changes made in the user interface in response to feedback garnered from a group of high school athletic directors and trainers who used the tool this past summer.