Notice: The MARFC Significant Flood Outlook graphic is intended to provide a general outlook for significant river flooding. It is not intended to depict small-scale events such as localized flooding and/or flash flooding, nor will it depict coastal and/or tidal flooding. This graphic will not depict minor river flooding as this implies only minimal or no property damage with possibly some public inconvenience. Please refer to products issued by local NWS offices for specific details. For a list of NWS offices and their links, go to: http://www.weather.gov .
NWS River Forecast Centers use the best available forecasts for future precipitation given the constraints of current hydrometeorological science. The number of hours or days into the future that precipitation amounts can be realistically forecast varies across the United States with seasons and geographic area. For example, forecast rainfall amounts for hurricanes and large scale weather systems can extend farther into the future than they can for local summer thunderstorms.
The MARFC issues 72 hours of forecast precipitation (QPF) throughout the year. This QPF is used as input to river forecasts as well as MARFC and National Significant River Flood Outlooks. Therefore, the daily Significant Flood Outlook Maps do not account for a full 5 days of QPF over the MARFC forecast area.
5-Day QPF for the United States can be found at Hydrometeorological Prediction Center website.