Overview of Purdue's Mobile Disdrometer Operations During VORTEX-SE

A primary objective of VORTEX-SE is to study the microphysical and thermodynamical properties of the downdrafts of potentially tornadic storms in the southeastern U.S. Many tornadic storms in this region develop in environments characterized by relatively lower instability, weaker low-level lapse rates, and deeper moist layers than their counterparts in the U.S. Great Plains.  These differences in environments may have important impacts on microphysical characteristics such as the rain drop size distribution (DSD), and on downdraft and cold pool thermodynamic properties.  Yet the level of variability of these characteristics both within and between these regions and environments, as well as their impact on tornado potential, is still largely unknown, and moreover is much less studied in the aforementioned lower-CAPE environments common to the southeast U.S.  Thus, there is a great need to characterize DSDs in tornadic or potentially tornadic storms in this region with high quality, targeted, and coordinated in situ and remote measurements of DSDs.

To this end, Purdue University, the University of Oklahoma, and the National Severe Storms Laboratory has jointly designed and built four mobile instrumented probes, dubbed Portable In Situ Precipitation Stations (PIPS), in support of the aforementioned VORTEX-SE objectives.  The PIPS were successfully deployed in several intensive operating periods (IOPs) during the VORTEX-SE 2016 field program.  In this study, we present an overview of these operations along with a preliminary analysis of the data and comparison with other platforms, including the Texas Tech University (TTU) StickNet probes and UMASS X-pol polarimetric radar observations.