Flash Flood Monitoring Using the New York State Mesonet

Flash flooding across New York State typically results from localized heavy precipitation, dam failures, or ice jams; historical events have posed a significant risk to life and property. Data from the National Centers for Environmental Information (NCEI) reports that between October 2006 and December 2018 an estimated $638 million in property damage was caused by localized heavy precipitation events (left figure below). For a more detailed review, the authors examined a flash flood event from 1 July 2017, as an estimated $18.5 million in property damage was reported from NCEI (right figure below). The town of Skaneateles, NY, reported an estimated $3.1 million in property damage, but was not in either of the two flash flood warning zones issued by the National Weather Service (NWS). This case study review evaluates what, if any, additional weather data could have improved the flood warnings for this location. Using data collected from the New York State Mesonet (NYSM; http://nysmesonet.org), a statewide network of 126 weather stations, we review precipitation totals, precipitation rates, and soil moisture for the event. We review changes in the soil moisture as precipitation falls in order to better understand the hydrological response to the intense rainfall. This study is a first step towards understanding how to better incorporate NYSM environmental information into flash flood monitoring across New York.