Advances in Development of the ASCE/SEI/AMS Standard for Wind Speed Estimation in Tornadoes and Other Windstorms

The ASCE Wind Speed Estimation Standards Committee (ASCE WSE) has moved forward since 2016 where it began outlining the scope of the challenge in establishing the standard (LaDue 2016). During May of 2017, the AMS entered into an MOU agreement with the Structural Engineering Institute (SEI) of the American Society of Civil Engineers (ASCE), to jointly develop a new consensus standard on estimation of wind speeds in tornadoes and other windstorms. This new standard will document methods for estimating wind speeds by direct measurement (in situ and radar) and by indirect techniques using damage to the built and natural environments, including a number of technical advances to the Enhanced Fujita Scale Method. The standard is intended for adoption and use by the National Weather Service and other affected stakeholders including practitioners and researchers in atmospheric science, engineering, emergency management, forestry, and other relevant disciplines.

The ASCE WSE has completed a draft of many sections of the standard and has begun balloting these sections within the committee. The balloting process requires all voting members of the committee to vote whether to accept or decline balloted items with comment. All comments need to be addressed by the ballot submitter(s). As of this presentation, the committee is just over midway through the process from concept to publication. The methods of wind speed estimation involved in the standard include two methods of measuring wind speeds (in-situ and radar), and four methods of post-event wind speed estimation (forensics analysis, EF-Scale, tree-fall pattern, and remote sensing), each represented by a subcommittee. The subcommittees ready to submit drafts of their entire chapters to committee ballot include radar, In-situ, and tree-fall pattern. The Forensics and EF-Scale subcommittees, responsible for larger chapters, have balloted sections in the full committee and other sections within their respective subcommittees. The ASCE WSE is well-integrated into the NWS Storm Data program and has submitted updated archival requirements.

While the standard is far from finalized, this presentation will preview the content within each chapter that may appear in the final standard. Much of this content is the result of research and development inspired during the course of the standards development process, and in accompanying submissions to this conference and other publications.

LaDue J. G., 2016: About the ASCE Tornado Wind Speed Estimation Standards Committee. 28th Conference Severe Local Storms. Portland, OR, 6B.1 [Available online at https://ams.confex.com/ams/28SLS/webprogram/Paper300684.html]