From Data to Action: How Urban Heat Mapping Campaigns Can Expose Vulnerabilities and Inform Local Heat Policy

UNC Libraries · 2025-03-13

This 90-minute virtual roundtable brought together local organizers from several Urban Heat Watch campaigns as well as representatives from NOAA and CAPA Strategies to discuss how the data and maps generated through these campaigns can be used to better understand heat-related vulnerability and inform effective heat mitigation strategies designed to capture those populations who are most vulnerable.

The Development and Accuracy Assessment of Wet Bulb Globe Temperature Forecasts

UNC Libraries · 2025-04-11

Heat is the leading cause of weather-related death in the United States. Wet bulb globe temperature (WBGT) is a heat stress index commonly used among active populations for activity modification, such as outdoor workers and athletes. Despite widespread use globally, WBGT forecasts have been uncommon in the United States until recent years. This research assesses the accuracy of WBGT forecasts developed by NOAA’s Southeast Regional Climate Center (SERCC) and the Carolinas Integrated Sciences and Assessments (CISA). It also details efforts to refine the forecast by accounting for the impact of surface roughness on wind using satellite imagery. Comparisons are made between the SERCC/CISA WBGT forecast and a WBGT forecast modeled after NWS methods. Additionally, both of these forecasts are compared with in situ WBGT measurements (during the summers of 2019–21) and estimates from weather stations to assess forecast accuracy. The SERCC/CISA WBGT forecast was within 0.6°C of observations on average and showed less bias than the forecast based on NWS methods across North Carolina. Importantly, the SERCC/CISA WBGT forecast was more accurate for the most dangerous conditions (WBGT > 31°C), although this resulted in higher false alarms for these extreme conditions compared to the NWS method. In particular, this work improved the forecast for sites more sheltered from wind by better accounting for the influences of land cover on 2-m wind speed. Accurate forecasts are more challenging for sites with complex microclimates. Thus, appropriate caution is necessary when interpreting forecasts and onsite, real-time WBGT measurements remain critical. Significance Statement This research assesses the accuracy of wet bulb globe temperature (WBGT) forecasts. WBGT is a heat stress index that accounts for impacts of air temperature, humidity, wind, and radiation. It is widely used in occupational, athletic, and military settings for heat stress assessment, yet WBGT forecasting in the United States is a relatively new development. These forecasts can be used by decision-makers to better plan activities. We found that WBGT forecasts by NOAA’s Southeast Regional Climate Center and Carolinas Integrated Sciences and Assessments were within 0.6°C of observations overall in North Carolina and less biased than forecasts based on methods used by the U.S. National Weather Service, which had larger, colder biases that present potential safety issues in planning.

Observations and Estimates of Wet-Bulb Globe Temperature in Varied Microclimates

UNC Libraries · 2025-04-12

Wet-bulb globe temperature (WBGT) is used to assess environmental heat stress and accounts for the influences of air temperature, humidity, wind speed, and radiation on heat stress. Measurements of WBGT are highly sensitive to slight changes in environmental conditions and can vary several degrees Celsius across small distances (tens to hundreds of meters). Relative to observations with an International Organization for Standardization (ISO)-compliant WBGT meter, this work assesses the accuracy of WBGT measurements made with a popular handheld meter (the Kestrel 5400 Heat Stress Tracker) and WBGT estimates. Measurements were made during the summers of 2019–21 in a variety of suburban and urban environments in North Carolina, including three high school campuses. WBGT can be estimated from standard weather station variables, and many of these stations report cloud cover in lieu of solar radiation. Therefore, this work also evaluates the accuracy of clear-sky radiation estimates and adjustments to those estimates based on cloud cover. WBGT estimated with the method from Liljegren et al. from a weather station were on average 0.2°C warmer than Observed WBGT, while the Kestrel 5400 WBGT was 0.7°C warmer. Large variations in WBGT were observed across surfaces and shade conditions, with differences of 0.9°C (0.3°–1.4°C) between a tennis court and a neighboring grass field. The method for estimating clear-sky radiation in Ryan and Stolzenbach was most accurate and the clear-sky radiation modified by percentage cloud cover was found to be within 75 W m −2 of observations on average. Significance Statement Wet-bulb globe temperature (WBGT) is a heat stress index that accounts for the effects of air temperature, humidity, wind, and radiation on humans. However, WBGT is not routinely measured at weather stations. This work demonstrated the accuracy of estimating WBGT with methods from Liljegren et al. (2008), finding it to be more accurate than measurements from a popular handheld meter, the Kestrel 5400 Heat Stress Tracker. Variations in WBGT that result in different danger levels were found between measurements over a tennis court and a neighboring grass field, and between sun and shade conditions. Understanding the magnitude of these differences and the biases with WBGT estimates and measurements can inform the planning of outdoor activity to robustly safeguard health.

The Regional Climate Center Program—Past, Present, and Future: Reflections from 40 Years of Regional Climate Services

Bulletin of the American Meteorological Society · 2024-07-29 · 1 citations

Abstract Since its inception in 1983, NOAA’s Regional Climate Center (RCC) Program has been providing timely, customized climate services for decision making across all climate-sensitive sectors. Through this 40-yr period, the RCC Program has not only seen but also has played an active role in, the evolution of climate services from the days of climate data libraries—where books of data were consulted to fulfill simple data requests—to coproduced tools that can calculate sectoral-specific, on-the-fly climate analyses in a matter of seconds. With new technologies emerging, the RCC Program is poised to build on its reputation as a trusted climate service provider by incorporating advanced methods for climate service delivery to continue to meet the needs of the nation. This publication will provide a look back at the evolution of regional climate services over the past 40 years, along with a vision for the future.

Impacts of weather-related road closures on daily habitual travel in North Carolina

Journal of Transport Geography · 2024-11-01 · 1 citations

From Data to Action: How Urban Heat Mapping Campaigns Can Expose Vulnerabilities and Inform Local Heat Policy

Bulletin of the American Meteorological Society · 2024-09-12 · 2 citations

Extreme heat poses a major hazard in urban areas due in large part to the urban heat island. Differences in observed temperatures and associated health effects between urban and surrounding rural locations are well documented (Yadav et al. 2023; Cheval et al. 2024). However, the complex nature of cities results in significant intraurban variability in temperature as well as variability in the underlying demographic and social characteristics of the urban population. The growing appreciation for intraurban temperature variability has led to field campaigns to measure the fine-scaled patterns of extreme heat across the urban landscape. Many of these campaigns have been conducted under the Heat Watch Program (NOAA 2024), which was developed by CAPA Strategies and is currently funded by NOAA. Since 2017, over 60 cities and communities have participated in the Heat Watch Program, resulting in detailed machine learning–generated thermal “fingerprints” using data collected by volunteers. While these maps reveal the geographic distribution of heat across a city, there remains a gap in applying these data to better understand and respond to local-scale inequities in heat exposure.

Changes in the associations between heatwaves and human mortality during two extreme hot summers in Shanghai, China

Sustainable Cities and Society · 2023 · 41 citations

• Demography
• Medicine
• Geography

Electric vehicle drive train with rollback detection and compensation

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2023-01-23

An electric vehicle drive train includes a controller for detecting and compensating for vehicle rollback, as when the vehicle is started upward on an incline. The vehicle includes an electric motor rotatable in opposite directions corresponding to opposite directions of vehicle movement. A gear selector permits the driver to select an intended or desired direction of vehicle movement. If a speed and rotational sensor associated with the motor indicates vehicle movement opposite to the intended direction of vehicle movement, the motor is driven to a torque output magnitude as a nonconstant function of the rollback speed to counteract the vehicle rollback. The torque function may be either a linear function of speed or a function of the speed squared.

The Development and Accuracy Assessment of Wet Bulb Globe Temperature Forecasts

Weather and Forecasting · 2023-11-29 · 4 citations

Abstract Heat is the leading cause of weather-related death in the United States. Wet bulb globe temperature (WBGT) is a heat stress index commonly used among active populations for activity modification, such as outdoor workers and athletes. Despite widespread use globally, WBGT forecasts have been uncommon in the United States until recent years. This research assesses the accuracy of WBGT forecasts developed by NOAA’s Southeast Regional Climate Center (SERCC) and the Carolinas Integrated Sciences and Assessments (CISA). It also details efforts to refine the forecast by accounting for the impact of surface roughness on wind using satellite imagery. Comparisons are made between the SERCC/CISA WBGT forecast and a WBGT forecast modeled after NWS methods. Additionally, both of these forecasts are compared with in situ WBGT measurements (during the summers of 2019–21) and estimates from weather stations to assess forecast accuracy. The SERCC/CISA WBGT forecast was within 0.6°C of observations on average and showed less bias than the forecast based on NWS methods across North Carolina. Importantly, the SERCC/CISA WBGT forecast was more accurate for the most dangerous conditions (WBGT > 31°C), although this resulted in higher false alarms for these extreme conditions compared to the NWS method. In particular, this work improved the forecast for sites more sheltered from wind by better accounting for the influences of land cover on 2-m wind speed. Accurate forecasts are more challenging for sites with complex microclimates. Thus, appropriate caution is necessary when interpreting forecasts and onsite, real-time WBGT measurements remain critical. Significance Statement This research assesses the accuracy of wet bulb globe temperature (WBGT) forecasts. WBGT is a heat stress index that accounts for impacts of air temperature, humidity, wind, and radiation. It is widely used in occupational, athletic, and military settings for heat stress assessment, yet WBGT forecasting in the United States is a relatively new development. These forecasts can be used by decision-makers to better plan activities. We found that WBGT forecasts by NOAA’s Southeast Regional Climate Center and Carolinas Integrated Sciences and Assessments were within 0.6°C of observations overall in North Carolina and less biased than forecasts based on methods used by the U.S. National Weather Service, which had larger, colder biases that present potential safety issues in planning.

Electric vehicle drive train with contactor protection

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2023-01-23

A drive train for an electric vehicle includes a traction battery, a power drive circuit, a main contactor for connecting and disconnecting the traction battery and the power drive circuit, a voltage detector across contacts of the main contactor, and a controller for controlling the main contactor to prevent movement of its contacts to the closed position when the voltage across the contacts exceeds a predetermined threshold, to thereby protect the contacts of the contactor. The power drive circuit includes an electric traction motor and a DC-to-AC inverter with a capacitive input filter. The controller also inhibits the power drive circuit from driving the motor and thereby discharging the input capacitor if the contacts are inadvertently opened during motoring. A precharging contactor is controlled to charge the input filter capacitor prior to closing the main contactor to further protect the contacts of the main contactor.