Infrasound observations from the 2019 Tornado Season

Tornado producing storms have been observed to emit infrasound (sound at frequencies below human hearing) up to 2 h before tornadogenesis. Weak atmospheric attenuation at these frequencies allows for long-range detection. Hence, passive infrasonic monitoring could be a method for long-range studying of tornadogenesis as well as tornado characterization. Identifying the fluid mechanism(s) that produce the infrasound production is critical to enable such capabilities, but currently there are insufficient observations to test potential mechanisms. The 2019 tornado season has been extreme, with over 1000 tornadoes in the United States. This includes numerous severe storms within the range of an infrasound array that was deployed at Oklahoma State University to monitor severe storm infrasound. The current work presents infrasound and, when possible, radar analysis of severe storms during 2019. [Work supported by NSF Grant Nos. 1539070 and NOAA NA18OAR4590307.]