Earth Satellite Imagery to Improve Official Tornado Databases
Sam Shamburger, National Weather Service, Nashville, TN
Official Storm Data and National Centers for Environmental Information (NCEI) tornado records are known to contain errors including incorrect track locations, erroneous occurrence times, and improper county or state attribution. In addition, National Weather Service storm surveys of tornado damage can be limited by poor road networks, inaccessible areas, and private properties resulting in incorrect or incomplete data. Therefore, high resolution satellite imagery has become increasingly useful in determining and refining tornado damage paths for official National Weather Service records.
This project re-analyzed all recorded tornadoes across Middle Tennessee over a 20 year period from 1995 to 2015. Using satellite imagery available in the Google Earth application along with archived radar data attainable through NCEI, the times, path lengths, path widths, locations, and details of numerous tornadoes during this timeframe were improved in the online National Weather Service Nashville database. Further analysis of Google Earth satellite imagery and archived radar data resulted in the discovery of a few previously unknown tornadoes, which were added to the NWS Nashville database. In addition, this analysis determined a few events that were clearly not tornadoes, which were removed from the online database. The result is a much more accurate historical tornado record than what currently exists in the official Storm Data records. This project will bring to light past inconsistencies in tornado damage surveys and official records, and show the need to re-analyze and correct past tornado events in the Storm Data and NCEI databases using modern tools.