An Examination of Near-Surface Mobile Observations from TORUS: What Does "Surface Based" Really Mean?

During the 2019 spring severe weather season in the central plains, the Targeted Observation by Radars and UAS of Supercells (TORUS) project set out to observe the occurrence of vorticity rivers, thought to play a significant role in tornadogenesis. These concentrated streamwise vorticity rivers have been consistently shown in simulated supercells with associated surface boundaries, but have yet to be directly captured by in situ observations. TORUS utilized a number of observational platforms to attempt to capture these features including: mobile radars, unmanned aircraft, larger piloted aircraft (NOAA P3), surface-based profiling systems, upper air soundings, and surface observations with mobile mesonets. The project ran from approximately May 15^th-June 15^th, 2019 and collected high quality data on a number of both tornadic and non-tornadic supercells.

In this talk, we discuss mobile mesonet observations from the TORUS project, continuing the work that was presented from the RiVorS project in 2017. An initial analysis of observed boundaries and gradients in events ranging from non-tornadic to marginally and significantly tornadic will be presented. Furthermore, as some of these boundaries have generally not been observed in the past, a discussion on potential sampling issues with previous instrumentation will be given. First looks at the data suggest that there are cases, especially those with significant tornadoes, that do not show surface fields similar to the simulated vorticity rivers. Two hypotheses are given for the inconsistency between observations and simulations: 1) vorticity rivers exist but are not always manifest in fields observed at 3 m height, or 2) observed supercell boundaries are not broadly consistent with the simulated features. This talk will mention future observing strategies and platforms that may be required to assess these hypotheses.