Toward the Development of Real-Time Normalized Burn Ratio (NBR) and Delta NBR Imagery from GOES-16/17 and the Suomi National Polar-Orbiting Partnership (SNPP)

Landscapes that have succumbed to wildfires, or burn scars, present especially difficult hydrologic forecasting challenges for National Weather Service (NWS) Offices since they can be conducive to the development of flash flooding and landslides. Past research has shown that the severity of burned soils and vegetation within the scar is directly related to the risk for these phenomena. In the U.S., a Burned Area Reflectance Classification map is generated to indicate the degree of burn severity, which is created initially from high-resolution satellite imagery from sources such as Landsat, and later by labor-intensive efforts conducted at the burn scar by Burned Area Emergency Response (BAER) teams. The challenge for operational meteorologists is that these sources of information are not readily available in near real-time, or often even shortly after the burn scar has developed. Landsat imagery, for example, may only be available about once every eight days, and cloudy conditions can obstruct observations of the burn scar during a single pass. Additionally, BAER teams cannot conduct assessments until the wildfire has been at least 40 percent contained (up to 80 percent in some regions), and the process itself can take additional days to weeks to complete. In non-federally owned lands, surveys may not even be conducted by BAER teams. All of this is problematic since heavy rain events can occur in the interim. To help remedy this gap in situational awareness, NASA SPoRT has developed the generation of NBR imagery in the Automated Weather Interactive Processing System (AWIPS) using data from the operational GOES 16 and 17 satellites, and from the VIIRS instrument aboard S-NPP. The advantage of making the imagery available in AWIPS is that forecasters can overlay it with other relevant data sets, and use it to properly adjust flash flood thresholds in programs internal to AWIPS. Similarly, hydrologists at NWS River Forecast Centers can use burn scar severity values to adjust forecast streamflow values. The generation of important delta-NBR (dNBR) imagery is a more complicated challenge, and is not currently available in AWIPS, but is being developed for dissemination online. NASA SPoRT is field-testing a prototype of the NBR and dNBR imagery with select NWS collaborators during the 2019 fire season. This presentation will discuss the development of the GOES and S-NPP NBR and dNBR imagery and their initial evaluation by real-time decision makers.