Experiences in using the EF-Scale since its inception
James G. LaDue, NOAA/NWS, Norman, OK ; and K. L. Ortega
Enough time has passed since the official adoption of the EF-Scale within the U.S. to have afforded damage surveyors to see the value of the EF-Scale in creating surveys with unprecedented detail while also seeing how much improvement needs to be done. We have surveyed multiple tornadoes of different intensities and have found the EF-Scale a valuable tool to create levels of detail in surveys not possible before. For the first time, we have used easily available aerial imagery, and GIS tools to map damage tracks with sufficient detail to easily map the damage track, contour damage intensity, and perform spatial analysis. This level of detail is now desired by a greater number of users (e.g., FEMA). However, the potential of precision masks potentially important errors in the scale that can easily affect the outcome of any survey. The authors and other surveyors have found that the progression of Degrees of Damage (DOD) in several Damage Indicators do not show the same progression documented in the scale as observed in actual surveys (e.g., softwood and hardwood trees, mobile homes, power poles). The level of confusion that results can be somewhat alleviated by comparing the DODs from multiple adjacent DIs. However the need still exists to revisit the methodology used to create the DODs for the DIs in question. Beyond modifying existing DIs, NWS surveyors have expressed a great desire to add objects and structures for which they commonly find in damage tracks to the list of official DIs, the most common being, vehicles, farm equipment and unreinforced downtown brick structures. Finally, a mechanism needs to be implemented in order for the EF-Scale to continue down a path of improvement.
Extended Abstract (2.3M)
Session 8B, Near-Surface Tornado Winds and Tornado
Tuesday, 28 October 2008, 1:30 PM-3:00 PM, South Ballroom
Browse or search entire meeting
AMS Home Page