Use of NASA Satellite Data in Tornado Damage Path Assessment
Carcione, Brian ; Laws, Kevin ; Jedlovec, Gary ; Molthan, Andrew ; Smith, Matthew

Final author: Frank LaFontaine, NASA SPoRT/Raytheon Corporation, Huntsville, Alabama

The 27 April 2011 tornado outbreak left behind multiple swaths of tornado damage across the southeastern United States. The Huntsville and Birmingham, Alabama, National Weather Service (NWS) county warning areas were significantly impacted by the outbreak, with approximately 60 individual tornado paths surveyed by NWS and University of Alabama in Huntsville personnel over a 53-county region. Staffing limitations at these forecast offices, combined with the incredible scope of damage, prevented fully detailed evaluation and documentation of every tornado path.

High-resolution NASA Earth Observation System satellite imagery has proved useful in examining and surveying storm damage in detail. Despite a large power outage that impacted the Huntsville area after the tornadoes, the NASA Short-term Prediction Research and Transition (SPoRT) Center provided 250-meter and 500-meter resolution imagery from the MODIS (Moderate Resolution Imaging Spectroradiometer) to impacted NWS forecast offices while storm surveys were still ongoing. NWS Huntsville and Birmingham were able to view the MODIS data within the Advanced Weather Interactive Processing System to validate the path width and length of several large tornadoes, including a long-track EF-5 tornado, and the EF-4 tornado which impacted both the Tuscaloosa and Birmingham, Alabama, metropolitan areas. The SPoRT Center also provided MODIS imagery in KML format to the affected offices, allowing the imagery to be overlaid with already-compiled storm survey data, permitting more precise comparisons of tornado path dimensions within the Google Earth software. In one case, the MODIS imagery prompted the survey team to adjust the exact tornado path across portions of northeast Alabama.

The SPoRT Center also acquired higher-resolution (15 meters) data from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) instrument aboard the NASA Terra satellite. While these data can be easily ingested and displayed within the NWS AWIPS system, the ASTER imagery in this case was georeferenced and provided to the NWS in KML format as well. Underlying land use can limit the utility of the ASTER imagery, particularly in heavily-farmed areas such as Limestone and Madison Counties in north Alabama. However, in other portions of Alabama, the ASTER imagery yielded details such as fluctuating path widths through much of the tornado life cycle, sections of more intense damage, and weaker tornado paths.

This presentation will include examples of the imagery used by the Huntsville and Birmingham NWS offices, and describe the operational utility of the imagery in completing and organizing storm surveys.