Hourly Precipitation Data (HPD) is digital data set DSI-3240, archived at the National Climatic Data Center (NCDC). The primary source of data for this file is approximately 5,500 US National Weather Service (NWS), Federal Aviation Administration (FAA), and cooperative observer stations in the United States of America, Puerto Rico, the US Virgin Islands, and various Pacific Islands. The earliest data dates vary considerably by state and region: Maine, Pennsylvania, and Texas have data since 1900. The western Pacific region that includes Guam, American Samoa, Marshall Islands, Micronesia, and Palau have data since 1978. Other states and regions have earliest dates between those extremes. The latest data in all states and regions is from the present day. The major parameter in DSI-3240 is precipitation amounts, which are measurements of hourly or daily precipitation accumulation. Accumulation was for longer periods of time if for any reason the rain gauge was out of service or no observer was present. DSI 3240_01 contains data grouped by state; DSI 3240_02 contains data grouped by year.

(Prototype - Under Development. Not to be relied upon for operational use.)This interactive web map shows real-time flood conditions across the United States and combines multiple informational layers to assist with River Forecast Center Decision Support Services for both internal and external partner use. This includes current and forecast flood conditions at service locations in the United States using live data from the National Weather Service Advanced Hydrologic Prediction System (AHPS) along with National Water Model (NWM) streamflow guidance across 2.7 Million reaches. In addition, current USGS streamflow observations along with NRCS snotel network observations can be viewed on top of a host of additional NOAA product layers including current radar and satellite imagery, past and future rainfall estimates, snowpack analysis, drought analysis, river and flash flood outlooks, weather hazard outlooks, severe weather, tropical outlook and cyclone forecasts, active hurricane tracks, and climate outlooks along with a variety of hydrologic, political and federal agency boundaries. Many of these layers have multiple temporal scales and all are viewable on top of standard basemaps, including world topographic maps.For a map that focuses on more general weather reports and current radar, see the Severe Weather Map.For a map that focuses on available National Water Model flow and anomaly layers, see the NWM Map.By using this AGOL web map, the user acknowledges that the NWM v1.0 output is prototype guidance and should not be considered an official NWS river forecast.About the data:Stream Gauges: This is Esri's Live Stream Gauges layer, symbolized to show only those gauges that are currently at or above flood stage. Click on a gauge to see the current depth, flow rate, and alert level. Five day forecasts from Advanced Hydrologic Prediction Service are shown where available.Population Density: This is Esri's World Population Estimate, which models the likely population of each 250 meter square cell, globally. It provides import context to the map, showing where flooding is likely to have a human impact.Flood Warnings (short and long term): These weather alerts are NOAA Weather Warnings, Watches, and Advisory data provided through the Common Alerting Protocol (CAP) Alert system. The long term warnings (flood warnings) are done on a county basis, while the short term warnings (flash flood and marine warnings) are more spatially precise. 72-hour Precipitation Forecast: This is the Quantitative Precipitation Forecast (QPF) from NOAA's National Digital Forecast Database. By default it shows the predicted total over the next 72 hours, but this forecast can also be viewed in six hour intervals.***** IMPORTANT disclaimer concerning NWM output *****The Office of Water Prediction (OWP) National Water Center is now producing water information from our National Water Model (NWM) version 1.0. Information about the prototype NWM output displayed on this map interface can be found in this Product Description Document. More information about the NWM is available athttp://water.noaa.gov/about/nwm. As this output is from the first version of the NWM, it does not yet contain information on the anthropogenic effects on streamflow and output should be viewed with caution. The output is undergoing extensive validation and verification to identify where updates to the science model parametrization and configurations can make the most improvements to the model output. The next version of the NWM will be released in the spring 2017 time frame. For official NWS river forecasts please see http://water.weather.gov.There is a NWM mapping interface in progress. In addition to the prototype NWM streamflow information, data layers of 2 snow products from the National Snow Analysis, Snow Depth and Snow Water Equivalent, are also available. The OWP is seeking to improve the availability and quality of its products and services based on user feedback. Comments regarding the Prototype Water Information Interface Webpage should be provided through the electronic survey via the link provided below: http://www.nws.noaa.gov/survey/nws-survey.php?code=NWMV1OUTPUTThe OWP also provides a range of NWS official water information through the following web sites.River observation and forecast information: http://water.weather.gov/ahpsSnow Information: http://www.nohrsc.noaa.govPrecipitation Frequency Estimates: http://www.nws.noaa.gov/oh/hdscContent from the sites above will be migrated to this new site over the next couple of years.Comments? Questions? Please Contact nws.nwc.ops@noaa.gov.By using this AGOL web map, the user acknowledges that the NWM v1.0 output is prototype guidance and should not be considered an official NWS river forecast.

Continuously updated US flooding information from the National Weather Service shows observed flooding locations, current & forecast precipitation, and flood warning areas. The stream gauges and weather watches layers allow you to identify features to get specific information such as flooding height, weather related issue, and severity. For a map that focuses on more general weather reports and current radar, see our Severe Weather Map.

About the data:

Stream gauges with flooding: This is an aggregated live feed derived from the NOAA/USGS Stream Gauges site using the National Weather Service’s River Observation data.

Flood Warnings (short and long term): This is an aggregated live feed derived from the NOAA Weather Warnings Watches and Advisory data provided through the Common Alerting Protocol (CAP) Alert system.

72-hour Forecast Total Precipitation: The data displaying forecast precipitation for the next 72 hours is Quantitative Precipitation Forecast (QPF). QPF is the amount of expected rainfall (in hundredths of inches) every six hours. This data is recorded by NDFD at 0000, 0600, 1200 and 1800. Organization: NDFD (National Digital Forecast Database)

Radar: Provided by AccuWeather, Inc.. For more information on the predictive services AccuWeather provides visit the ArcGIS Marketplace.

(Prototype - Under Development. Not to be relied upon for operational use.)This interactive web map shows real-time flood conditions across the United States and combines multiple informational layers to assist with River Forecast Center Decision Support Services for both internal and external partner use. This includes current and forecast flood conditions at service locations in the United States using live data from the National Weather Service Advanced Hydrologic Prediction System (AHPS) along with National Water Model (NWM) streamflow guidance across 2.7 Million reaches. In addition, current USGS streamflow observations along with NRCS snotel network observations can be viewed on top of a host of additional NOAA product layers including current radar and satellite imagery, past and future rainfall estimates, snowpack analysis, drought analysis, river and flash flood outlooks, weather hazard outlooks, severe weather, tropical outlook and cyclone forecasts, active hurricane tracks, and climate outlooks along with a variety of hydrologic, political and federal agency boundaries. Many of these layers have multiple temporal scales and all are viewable on top of standard basemaps, including world topographic maps.For a map that focuses on more general weather reports and current radar, see the Severe Weather Map.For a map that focuses on available National Water Model flow and anomaly layers, see the NWM Map.By using this AGOL web map, the user acknowledges that the NWM v1.0 output is prototype guidance and should not be considered an official NWS river forecast.About the data:Stream Gauges: This is Esri's Live Stream Gauges layer, symbolized to show only those gauges that are currently at or above flood stage. Click on a gauge to see the current depth, flow rate, and alert level. Five day forecasts from Advanced Hydrologic Prediction Service are shown where available.Population Density: This is Esri's World Population Estimate, which models the likely population of each 250 meter square cell, globally. It provides import context to the map, showing where flooding is likely to have a human impact.Flood Warnings (short and long term): These weather alerts are NOAA Weather Warnings, Watches, and Advisory data provided through the Common Alerting Protocol (CAP) Alert system. The long term warnings (flood warnings) are done on a county basis, while the short term warnings (flash flood and marine warnings) are more spatially precise. 72-hour Precipitation Forecast: This is the Quantitative Precipitation Forecast (QPF) from NOAA's National Digital Forecast Database. By default it shows the predicted total over the next 72 hours, but this forecast can also be viewed in six hour intervals.***** IMPORTANT disclaimer concerning NWM output *****The Office of Water Prediction (OWP) National Water Center is now producing water information from our National Water Model (NWM) version 1.0. Information about the prototype NWM output displayed on this map interface can be found in this Product Description Document. More information about the NWM is available athttp://water.noaa.gov/about/nwm. As this output is from the first version of the NWM, it does not yet contain information on the anthropogenic effects on streamflow and output should be viewed with caution. The output is undergoing extensive validation and verification to identify where updates to the science model parametrization and configurations can make the most improvements to the model output. The next version of the NWM will be released in the spring 2017 time frame. For official NWS river forecasts please see http://water.weather.gov.There is a NWM mapping interface in progress. In addition to the prototype NWM streamflow information, data layers of 2 snow products from the National Snow Analysis, Snow Depth and Snow Water Equivalent, are also available. The OWP is seeking to improve the availability and quality of its products and services based on user feedback. Comments regarding the Prototype Water Information Interface Webpage should be provided through the electronic survey via the link provided below: http://www.nws.noaa.gov/survey/nws-survey.php?code=NWMV1OUTPUTThe OWP also provides a range of NWS official water information through the following web sites.River observation and forecast information: http://water.weather.gov/ahpsSnow Information: http://www.nohrsc.noaa.govPrecipitation Frequency Estimates: http://www.nws.noaa.gov/oh/hdscContent from the sites above will be migrated to this new site over the next couple of years.Comments? Questions? Please Contact nws.nwc.ops@noaa.gov.By using this AGOL web map, the user acknowledges that the NWM v1.0 output is prototype guidance and should not be considered an official NWS river forecast.

Continuously updated US flooding information from the National Weather Service shows observed flooding locations, current & forecast precipitation, and flood warning areas. The stream gauges and weather watches layers allow you to identify features to get specific information such as flooding height, weather related issue, and severity. For a map that focuses on more general weather reports and current radar, see our Severe Weather Map.About the data: Stream gauges with flooding: This is an aggregated live feed derived from the NOAA/USGS Stream Gauges site using the National Weather Service’s River Observation data.Flood Warnings (short and long term): This is an aggregated live feed derived from the NOAA Weather Warnings Watches and Advisory data provided through the Common Alerting Protocol (CAP) Alert system.72-hour Forecast Total Precipitation: The data displaying forecast precipitation for the next 72 hours is Quantitative Precipitation Forecast (QPF). QPF is the amount of expected rainfall (in hundredths of inches) every six hours. This data is recorded by NDFD at 0000, 0600, 1200 and 1800. Organization: NDFD (National Digital Forecast Database)Radar: Provided by DTN https://www.dtn.com/