Flood Level Observation, Operations, and Decision Support Act or the FLOODS Act This bill addresses forecasting and the communication of flood, tornado, and hurricane events by the National Oceanic and Atmospheric Administration (NOAA). For example, the bill directs NOAA to establish a National Integrated Flood Information System to inform and provide for timely decisions to reduce flood-related effects and costs. NOAA must also establish partnerships with institutions of higher education and federal agencies to improve total water predictions. In addition, NOAA must (1) evaluate and improve flash flood watches and warnings, (2) estimate and communicate the frequency of precipitation, and (3) identify gaps in the availability of snow-related data to assess and predict floods and flood impacts. Further, NOAA must ensure that the tornado warning improvement and extension program periodically examines the value of incorporating innovative observations, such as acoustic or infrasonic measurements, observations from phased array radars, and observations from mesonets (i.e., a network of certain weather observing stations). In addition, the National Weather Service must designate a service coordination hydrologist at each of its River Forecast Centers to increase impact-based decision support services at the state and local level. Finally, the bill establishes an Interagency Committee on Water Management and Infrastructure to ensure that federal agencies that engage in water-related matters work together where such agencies have joint or overlapping responsibilities.