An Overview of the 13-14 April 2018 North Louisiana Severe Weather Event during VORTEX-SE

A multi-day severe weather episode, with approximately 70 confirmed tornadoes, impacted portions of the southeastern U.S. on 13-15 April 2018. The bulk of these tornadoes occurred on 13-14 April in Arkansas, Louisiana, and Mississippi. In particular, northern Louisiana and southern Arkansas were impacted by a double round of severe weather on 13-14 April, including late afternoon/early evening tornadic supercells, and an overnight tornadic quasi-linear convective system (QLCS). A total of 23 tornadoes occurred in this region. This event is distinct in that operations associated with the Verification of the Origins of Rotation in Tornadoes Experiment – Southeast (VORTEX-SE) were conducted in north Louisiana, leading to an exceptional set of observations for both the tornadic supercells and the QLCS.

VORTEX-SE observations from the following platforms were collected during the event: instrumentation aboard the NOAA P-3 aircraft, including the dual tail Doppler radars (TDRs) and a Compact Raman Lidar (CRL), the University of Louisiana Monroe (ULM) polarimetric S-band Doppler radar (KULM), two ULM iMet radiosonde systems, and two University of Oklahoma (OU) C-band Shared Mobile Atmospheric Research and Teaching (SMART) radars. Of specific interest are the KULM data, operating in a 5-elevation angle, low-level priority mode yielding a new volume scan every 90-s, and the ULM radiosonde data, where 11 soundings were launched during the event. KULM collected a unique dataset on multiple supercells and the tornadic QLCS near Monroe, LA. One tornadic supercell, near Calhoun, LA, produced three EF-1 tornadoes within 25-30 km range of KULM, and the storm was observed during 28 consecutive P-3 flight legs. The purpose of this presentation is to (1) give an overview of the 13-14 April 2018 severe weather event within the north Louisiana VORTEX-SE operational domain, (2) overview the unique observations that will be made available to the severe storms community as part of the VORTEX-SE operations, and (3) show preliminary single Doppler analyses from KULM of the Calhoun, LA supercell.

NOTES: There are two companion abstracts being submitted by Conrad Ziegler (detailed look at the tornadic supercells using the P3) and Mike Biggerstaff (for tornadic QLCS observations near Shreveport). If all three are accepted, we request the order be: Murphy, Ziegler, and Biggerstaff. Thanks.