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). Among other provisions, the bill directs NOAA to establish a National Integrated Flood Information System to better inform and provide for more timely decision-making to reduce flood-related effects and costs; establishes partnerships with institutions of higher education and federal agencies to improve total water predictions; designates a service coordination hydrologist at each National Weather Service River Forecast Center to increase impact-based decision support services at the state and local level; requires NOAA to evaluate and improve flood watches and warnings and communication of information to support preparation and responses to floods; ensures 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; requires NOAA to estimate and communicate the frequency of precipitation; establishes an Interagency Coordinating Committee on Water Management to ensure that federal agencies that engage in water-related matters, including water storage and supplies, water quality and restoration activities, water infrastructure, transportation on rivers and inland waterways, and water forecasting, work together where such agencies have joint or overlapping responsibilities; and directs NOAA to conduct an analysis of gaps in the availability of snow-related data to assess and predict floods and flood impacts.