Case Study of the Ruston, Louisiana, EF3 Tornado of 25 April 2019

In late April of 2019, there was an active pattern over the Southern Plains, resulting in a unique round of severe weather for the Shreveport, Louisiana National Weather Service Forecast Office (WFO SHV) County Warning Area (CWA). A total of 7 tornadoes occurred during this distinct severe weather scenario. This study will focus on the tornado of April 25th impacting Ruston, Louisiana (hereafter referred to as the “Ruston Tornado”).

The event producing the Ruston Tornado was not expected to produce significant severe weather - mainly owing to a relatively tame forecast juxtaposition of instability and wind shear. Significant mesoscale/storm-scale enhancement of the severe weather “parameter space” (tied to movement of a supercell along a pre-existing outflow boundary) occurred in this case. This project analyzes the Storm Prediction Center’s (SPC) hourly mesoanalysis and their previous studies on baroclinic boundary and cold frontal regime supercells. Multiple radar images were also used in this project to show its genesis through its death. Thus, upon further analyzation, values showed to have supported tornadogenesis, but not for an EF-3. Using the previous studies and the radar images, micro-scale enhancements were made to the supercell, causing it to produce an EF-3 tornado. Our study will explore the details of why the event was not anticipated to be anything serious based on the forecasted weather parameters and outlooks, and how this long-track supercell was able to produce such a tornado.