6 Teachable Moments From An Atlanta Rush Hour Downpour

InnovationScience6 Teachable Moments From An Atlanta Rush Hour DownpourByMarshall Shepherd,Senior Contributor.Follow AuthorMay 22, 2026, 08:05am EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.Closeup of high water flooding on neighborhood street.gettyThis week the city of Atlanta experienced significant flooding from a scattered rainstorm Wednesday afternoon. Major interstates were inundated during afternoon rush hour, drivers were trapped in cars, and autonomous vehicle company Waymo suspended services. In the aftermath of this disruptive flash flooding event, I noticed several misperceptions and flawed assumptions in conversations with friends and on social media. Here are six teachable moments from rush hour downpour.Percent Chance Of Rain And IntensityA close colleague and friend asked, “How is this flooding possible when you said there was only a 30% chance of rain?” He was confusing probability with intensity. The percent chance of rain is not necessarily an indicator of rainfall intensity. “1. A close colleague and friend said to me how is that possible when you said there was only a 30% chance of rain. He was confusing probability with intensity. The percent chance of rain is not necessarily an indicator of the intensity of rain. Probability of rain considers the multiplication of area covered times confidence in the forecast. A National Weather Service document provides a great example. ”If the forecaster was 80% certain that rain would develop but only expected to cover 50% of the forecast area then the forecast would read 40% chance of rain for any given location," noted the NWS website. If widespread rain is expected over 100% of the area but with only 40% certainty, that would also be a 40% chance. The minimum expected amount is one hundredth of an inch, but there is no information about intensity.Official rainfall total for Atlanta on May 20, 2026.NWS and Brad Nitz/WSBMORE...