What is already known:
What this study adds:
Flash floods are dangerous natural hazards that can cause damage to life and property. Currently, they are one of the primary causes of weather-related fatalities in the United States. Recently, the National Weather Service has started issuing an Impact-Based Warnings (IBW) for flash flood events, which allows forecasters to add stronger language to their warning text products based on the impacts that are possible or occurring. The IBW categories are Base, Considerable and Catastrophic. This project classified a database of 141 flash flood events from 2013-2019 bases on their perceived IBW categories using specific keywords found in each report. To help with the classification, information from social media such as Twitter and Facebook posts, news articles, pictures and videos were also analyzed. The classification of the events was done twice depending on how to account for reports of closed roadways. For the first time the results showed that 19.3% of the events were base, 62.1% were considerable and 18.6% were catastrophic. After re-classifying the roadway reports as base (instead of considerable), the results showed that 35.5% were base, 47.5% were considerable and 17.0% were catastrophic. It was concluded that the analysis of the events depends on perspective which creates a major challenge at the time of the classification due to the keywords being ambiguous some of the times.