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21

Apr

2016

UAS Tornado Damage Assessment in Alabama for VORTEX-Southeast Field CampaignUnmanned Aircraft Systems (UAS) continue to rapidly respond to hazardous weather events.

For the first time since the commencement of the VORTEX-Southeast field campaign, which is centered in north Alabama for most of this Spring, a tornadic storm presented itself for thorough scientific investigation in the midst of an armada of meteorological instrumentation that was deployed across a focused portion of the region through a collaborative partnership between several universities and NOAA labs across the country. While most of these sensors are specifically geared toward acquiring high fidelity atmospheric data in the hours leading up to severe storm development and then actual observations of an existing storm, there was another set of state of the art platforms and sensor combinations waiting in the wings to perform its mission *after* the storm had passed. Unmanned Aircraft Systems (UAS, or "drones") are proving, more and more, to provide important pieces of information in the assessment of damage caused by severe storms and other types of natural and man-made disasters. Two separate UAS platforms were used to analyze the damage caused by the tornado in Morgan County, AL on the night of March 31, 2016, which stretched approximately 8 miles in length, the worst of which was classified as EF-2. First up was a DJI S-1000 octocopter that was used by the NOAA Air Resources Laboratory (ARL) ATDD group out of Oak Ridge, TN to hover over and focus in on a few key areas of damage along the tornado path. While the

octocopter had been used several times over the previous year to research a new approach for obtaining lower atmospheric meteorological in-situ observations with a retrievable sensor payload, this was the first opportunity that the NOAA ARL ATDD team had to utilize the very same platform for a completely different type of mission, aerial storm damage assessment, owing to the multi-purpose capabilities that are presented by UAS technology. Next, a fixed wing UAS platform was utilized by the "enrGies" commercial UAS engineering and operations group out of Huntsville, AL to fly along larger transects of the tornado damage path with increased attention still being paid to certain, key areas of scientific interest. The operation was coordinated through the Morgan County, AL Emergency Management Agency, under the leadership of Director Eddie Hicks, and the high-resolution aerial imagery is to be processed and delivered by enRgies to the county, the local National Weather Service office in Huntsville, and to the physical science team working in the VORTEX-Southeast campaign. The capability of being able to map out a tornado damage path with high-resolution aerial imagery and use that data in comparison with other acquired observations in the VORTEX-Southeast project compounds the tremendous benefits already being reaped through this concentrated research and operational activity. As explained by Tony Lyza, University of Alabama in Huntsville student and Ph.D. Candidate, who assisted with the initial NWS ground-based damage survey, "There is only so much you can do to perform these types of extensive surveys from the ground; there were several instances when we had to stop short and turn back after crawling over two- or three-hundred yards of tangled and uprooted trees in the more dense areas of the

forested locations." Mr. Lyza went on to explain the uniqueness of this particular tornado event, based on the initial survey, citing locations along the damage path in which the apparent behavior and strength of the tornado was contrary to many of the leading scientific hypotheses regarding how tornadic storms might respond in locations of varying topography, up and down hilly and mountainous terrain. "Having a high-resolution aerial overview of the damage produced by this tornado event will go a long way toward assisting us in the science and in meeting many of the objectives of this field campaign." This work continues to support the NOAA UAS Program's Rapid Response Strategy.