| Summary: | Study region: Iowa and the Nishnabotna watershed (Iowa), Midwest U.S. Study focus: Historically, Iowa and the Midwest have faced floods during the summer season. Some historical floods on record are the 2008 and 2013 floods. In March 2019, a meteorological bomb cyclone set the conditions for an unexpected major snow-related flood. This study (1) presents a comprehensive analysis of the March 2019 flood and asses the early-spring peak flows trends, (2) explores the use of a parsimonious hydrological model with a snow component, and (3) validates the model performance for the last 20 years. New Hydrological insights: The March 2019 event was an extreme flood event that set records on at least 10% of the USGS gauges in Iowa. Moreover, the early spring peak flow analysis showed a significant increasing trend between February and April. In this period, the trend is positive for most gauges, with more than a 30% increase at an annual rate of 4% of the mean yearly peak flow. These findings showed the relevance of snow-detonated floods and their regional understanding. Considering the results' significance, we provided evidence that HLM and a conceptual snow component can represent, forecast, and provide insights regarding snow-detonated events.
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