Thermodynamic Observations Above the Ground in Convective Storms from Balloonborne Probes Acting as Pseudo-Lagrangian Drifters

Over the past several decades, our understanding of tornado formation and other storm processes has been guided by theory, numerical simulations, and observations. Observations, in particular, are needed to validate the processes suggested by numerical model results. With the advent of mobile Doppler radar, wind and precipitation fields have been well observed, driving our understanding forward. Thermodynamic fields, on the other hand, have been more elusive, with limited soundings and transects by instrumented cars beneath storms. The lack of observations above the ground within the storm’s cold pool is unfortunate, as leading theories for processes such as tornadogenesis depend strongly on the thermodynamic properties in this region of the storm.

In the spring of 2017, we used a novel approach to collect important observations above the ground using a balloon-borne system. Two balloons were employed, with one jettisoned at a particular altitude, leaving the remaining balloon and lightweight sonde with a very low fall speed, acting as a pseudo-Lagrangian drifter. The storm-relative winds carried the probe through areas of interest in the storm that have eluded other sampling methods. We will show observations within supercells from this proof-of-concept experiment and discuss our plans for future development and deployment.