The NWA April Webinar will be held on Wednesday, April 5, 2017 at 10 am CT/11 am ET.
Go-To-Webinar link to register: https://attendee.gotowebinar.com/register/3607791601860038403
Speakers are Jared Allen and Brett Williams, both of the Austin/San Antonio WFO.
Presentation Outline: A tornadic Quasi-Linear Convective System (QLCS) produced 9 confirmed tornadoes over a two hour period across South-Central Texas 19-20 Feb. 2017. Three EF2's, two EF1's and four EF0's tornadoes resulted with the most notable showing a clear Tornado Debris Signature (TDS) in the north-central San Antonio metro area (More information on the event can be found here). Going back to 2005, the 19-20 Feb. event resulted in the second largest number of confirmed tornadoes (of any storm mode) in the NWS Austin/San Antonio's County Warning Area (CWA). However, leading into the event, tornadoes were not well anticipated per model output of low 0-1km and 0-3km Storm Relative Helicity (SRH) and mostly outflow dominated storms occurring. So what caused a semi-strong and mostly outflow dominated QLCS to ramp up into a widespread mesovortex/tornado and straight-line wind damage producing QLCS? Research by Schaumann and Pryzbylinski (2012) and McKenna Stanford (2013) tested and developed the "3-ingredient" method in identifying favorable mesoscale environments for mesovortex generation, intensification, and tornadogenesis within QLCS structures. This presentation will introduce the "3-ingredient" concept and apply it to the South-Central Texas tornadic QLCS event through radar and mesoscale analysis.