Moving from Treading Water to Catching the Wave: An Analysis of Urban Flash Flood Messaging and the Potential for Improvement (164)

Melissa Huffman, NWS Houston/Galveston, Dickinson, Texas

Katie Landry-Guyton, NWS Houston/Galveston



Since 2015, the Houston metropolitan area has endured eight flood events in which over seven inches of rain were observed. Three of these events resulted in the issuance of a Flash Flood Emergency. All of these events occurred at night with the majority of the rainfall occurring within only a few hours of the beginning of the event. In all, these events have claimed the lives of over 60 people with almost all of the fatalities occurring in vehicles or amongst individuals moving around in the flood waters.

Over 6.5 million people in the Houston area are regularly exposed to rapid onset flood events. As such, the NWS recognizes the need for efficient message coordination amost public safety partners. This coordination includes both communicating an escalating flood threat and transitioning out of an active flood event. The NWS Houston/Galveston office, in partnership with Harris county, the City of Houston, the Texas Department of Public Safety, Houston TranStar, and representatives from the local media, have worked to develop a tiered messaging approach to expedite flash flood message coordination to save more lives. This tiered approach is based on increasing threat/impact level from 1 to 5. This presentation will include an analysis of NWSChat in Houston's seven major flood events to identify messaging trends as well as preliminary results from the use of a tiered messaging approach.