The May 21, 2024, Iowa Tornado Outbreak: A Meteorological Breakdown

In-depth meteorological breakdown of the severe weather outbreak centered on southwest Iowa on May 21, 2024, which included the Carbon, IA EF3 and Greenfield, IA EF4. Fast-moving storms, including supercells, developed in southeast Nebraska and southwest Iowa during the early afternoon on May 21, eventually moving east into an environment favorable for significant severe weather. In this video, we'll take a deep dive into the background meteorology that fueled this event before discussing the incredibly unique convective evolution that took place leading up to and during the Greenfield EF4. We’ll also analyze some high-resolution, mobile radar data of the Greenfield tornado, which packed winds of over 300 mph. ***Sorry for the audio issue from 16:20-16:41. Here's what I'm supposed to be saying during that time: "To start the day at 12z, we see a profile comprised of modest instability and steep lapse rates elevated atop fairly limited low-level thermodynamics. Low-level shear was already strong, with ample hodograph curvature and effective storm-relative helicity nearing 250 m2/s2, in part due to easterly surface winds near or perhaps just north of the synoptic warm front." ---------------------------------------- Thumbnail image from Isaac Polanski (via NWS Des Moines) and Chris Riske. Huge thank you to Celton Henderson and Chris Riske for providing their footage of the Carbon and Greenfield tornadoes for use in this video. ---------------------------------------- Contents 0:00 Introduction 1:44 Meteorological analysis begins 10:10 Radar overview begins 11:04 Unique convective evolution 16:02 RAP proximity sounding analysis 18:13 Other notable tornadoes 19:36 Unusual right turn before dissipation 21:14 DOW data analysis 23:54 Wrap-up Become a Patreon member today to support the channel:   / convectivechronicles   Facebook:   / convectivechronicles   X:   / convchronicles   Instagram:   / convectivechronicles   ---------------------------------------- Resources NWS Des Moines event page: https://www.weather.gov/dmx/2024-May-... NWS Quad Cities event page: https://www.weather.gov/dvn/summary_0... NWS LaCrosse event page: https://www.weather.gov/arx/may2124 Greenfield tornado damage analysis by June First's Ethan Moriarty:    • Was Greenfield an EF5 Tornado? - DAMAGE AN...   Statement on DOW data analysis from University of Illinois: https://web.archive.org/web/202406240... Nixon and Allen (2021): "Anticipating Deviant Tornado Motion Using a Simple Hodograph Technique" - https://journals.ametsoc.org/view/jou... Wakimoto and Wilson (1989): "Non-supercell Tornadoes" - https://journals.ametsoc.org/view/jou... Kurdzo et al. (2015): "High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado" - https://journals.ametsoc.org/view/jou...