The Parkersburg, IA, EF-5 Tornado of May 25, 2008: A Case Study

In-depth discussion of the Parkersburg, IA, EF5 tornado of May 25, 2008. We'll take a deep dive into the meteorology behind this event, including the unique and complex surface pattern, how gravity waves may have impacted the development of the Parkersburg supercell, how the wind profile modulated storm characteristics, and much more.

Thumbnail images from KWWL Storm Track 7 and the Waterloo-Cedar Falls Courier.
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Chapters:

0:00 Introduction
2:47 Meteorological discussion begins
5:12 Complex surface pattern
8:38 Discussion of gravity waves
14:16 Storm merger
15:09 Descending reflectivity core
17:18 Role of gravity waves in storm intensification
20:13 Tornado progression, supercell discreteness
21:53 Observed sounding analysis
24:10 RUC model proximity sounding analysis
29:07 Brief discussion of path irregularities
31:14 Wrap-up
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Resources:

NWS Des Moines poster on Parkersburg: https://www.weather.gov/media/dmx/Sig...

NWS Des Moines final damage survey and event timeline: https://www.weather.gov/media/dmx/Sig...

NWS Des Moines service assessment: https://www.weather.gov/media/dmx/Sig...

"The Parkersburg, IA Tornado: 25 May 2008" - Marshall et al. (2008): https://ams.confex.com/ams/pdfpapers/...

"Gravity Waves: Those Important to Operational Weather Forecasting" - Schaub (2005): https://www.weather.gov/media/hun/res...

"The Synoptic Setting and Possible Energy Sources for Mesoscale Wave Disturbances" - Uccellini and Koch (1987): http://weather.ou.edu/~hblue/metr6413...

"The Interactions of Gravity Waves with Mesocyclones: Preliminary Observations and Theory" - Coleman and Knupp (2008): https://journals.ametsoc.org/view/jou...

"A Preliminary Survey of Rear-Flank Descending Reflectivity Cores in Supercell Storms" - Rasmussen et al. (2006): https://journals.ametsoc.org/view/jou...

US Tornadoes Case Archive: https://www.ustornadoes.com/case-arch...