Month: May 2017

May 2017 Blog Post

TWIRL– Tornadic Winds: In-situ and Radar measurements at Low levels

Haag engineer Tim Marshall will be part of the TWIRL PROJECT from MAY 7-JUNE 15. TWIRL stands for “Tornadic Winds: In-situ and Radar measurements at Low levels”.  TWIRL’s mission is to deploy instrumented pods in the paths of tornadoes so they can use these data to correlate wind speeds with the Doppler on Wheels (DOW) radar observations. Tim will be working for the Center for Severe Weather Research (CSWR), which is a non-profit science group, funded by the National Science Foundation.

“TWIRL researchers are focusing on low-level winds flowing into the cores of tornadoes,” said Ed Bensman, program director in NSF’s Division of Atmospheric and Geospace Sciences, which funds TWIRL. “They’re using a combination of surface weather sensors placed ahead of developing storms, and Doppler-on-Wheels [DOW] mobile weather radars. From TWIRL, we will gain a better understanding of the role low-level winds play in the development of tornadoes, and why some tornadoes become the most violent.” See more information about TWIRL here.

Tim is honored to be selected for this 5th deployment with the TWIRL team, and the only private person involved in this project.  All other TWIRL members are scientists affiliated with CSWR, universities, or graduate students in atmospheric science.

Tim’s interest in tornadoes, which led to his career as a forensic engineer and meteorologist, started when he was just 10 years old. In 1967, an F-4 tornado went through Oak Lawn, Illinois, just a 1/2 mile from where Tim and his family lived at the time. It was a devastating event which killed 30 people and left a path of destruction. Tim gave an illuminating presentation on how he got involved with tornadoes and the TWIRL project at the University of Nebraska Lincoln’s Weatherfest on April 7th, available here, through UNL.

Tim Marshall presents TWIRL at the University of Nebraska Lincoln’s Weatherfest, April 7, 2017. 


Tim Marshall, P.E., Haag Principal Engineer

Tim Marshall is a structural engineer and meteorologist.  He has served as a Haag Engineer since 1983, assessing damage to 1000s of structures (particularly damage caused by wind and other weather phenomena). He has written numerous articles, presented countless lectures, and appeared on dozens of television programs in order to share his extensive knowledge re: storms and the resultant damage.  He is a primary author of many Haag Education materials, including the Haag Certified Inspector-Wind Damage course.  He is also a pioneering storm chaser and was editor of Storm Track magazine.  See his profile here.