Data and Web Services Catalog

• National Forecast and Observed shapefile downloads: Obs and FCST Shapefile Downloads
  • Observed Shapefile : Most recent observation values
    • Observed River Values
  • Forecast Shapefile: Maximum value within forecast period
    • Maximum Forecast 24 hours
    • Maximum Forecast 48 hours
    • Maximum Forecast 72 hours
    • Maximum Forecast 96 hours
    • Maximum Forecast 120 hours
    • Maximum Forecast 144 hours
    • Maximum Forecast 168 hours
    • Maximum Forecast 192 hours
    • Maximum Forecast 216 hours
    • Maximum Forecast 240 hours
    • Maximum Forecast 264 hours
    • Maximum Forecast 288 hours
    • Maximum Forecast 312 hours
    • Maximum Forecast 336 hours
    • Maximum Forecast Entire Period
• Precipitation data downloads: Quantitative Precipitation Estimate (QPE) Data Downloads
• Partner FIM services data downloads: Partner FIM Data Downloads
• Long Range River Flood Risk: Flood levels based on thresholds for the 3 months period
  • Long Range River Flood Risk Shapefile: Long Range River Flood Risk Shapefiles Download
    • Long Range Flood Risk - 3 month, 5%
    • Long Range Flood Risk - 3 month, 10%
    • Long Range Flood Risk - 3 month, 25%
    • Long Range Flood Risk - 3 month, 50%
    • Long Range Flood Risk - 3 month, 75%
    • Long Range Flood Risk - 3 month, 90%
    • Long Range Flood Risk - 3 month, 95%
  • Long Range River Flood Risk csv download
• NWM Hydrofabric and Parameter Shapefiles: NWM Shapefile Downloads
• NWS Watch Warning and Advisory (WWA) Data: WWA Shape files

• River Forecast Centers Quantitative Precipitation Estimates (QPE) GIS Web Services

  The 13 National Weather Service (NWS) River Forecast Centers (RFC) produce Quantitative Precipitation Estimates (QPE) for their individual RFC areas. The RFCs produce the data using a multi-sensor approach utilizing NWS 88D radar estimates of precipitation, automated and manual precipitation gauges and satellite estimates of precipitation. These QPEs are used as input into their hydrologic models to produce NWS river forecasts and guidance products. The QPEs from each RFC are combined into a single mosaic to create a QPE product that covers the lower 48 states, Alaska and Puerto Rico. The data are on an approximate 4km x 4km grid cell scale.

  The individual hourly data products (labeled Since 12Z Observed and those labeled Last X hours) contain data for the labeled time frame. These products are updated every hour to incorporate the most recent data.

  The individual daily data products (Today’s Analysis Observed, those labeled Last X Days Observed, and those labeled X To Date Observed.) represent a 24 hour total ending at 12 UTC on the indicated date. These 24-hour data are then summed together to produce multi-day precipitation totals. Normal precipitation data are also produced for the Today’s Analysis Observed and multi-day summations of 7 days or greater using data from the PRISM Climate Group. Percent of normal and departure from normal comparisons are also available by comparing the QPE data with the PRISM normal data. The daily data may be updated several times between 12UTC and 21UTC each day as updated data becomes available.

• Watch Warning and Advisory GIS Web Services

  Watch - A watch is used when the risk of a hazardous weather or hydrologic event has increased significantly, but its occurrence, location, and/or timing is still uncertain. It is intended to provide enough lead time so that those who need to set their plans in motion can do so.

  Warning - A warning is issued when a hazardous weather or hydrologic event is occurring, is imminent, or has a very high probability of occurring. A warning is used for conditions posing a threat to life or property.

  Advisory - The expected weather condition has a pretty good chance of occurring, even a likely chance of occurring, but typically an advisory is used for less severe type of weather conditions. A Wind Advisory might be issued or a Freezing Rain Advisory issued instead of a High Wind Warning or an ice Storm Warning.

  • Link to graphical web page https://www.weather.gov/
  • Link to metadata

  Questions/Concerns about the service, please contact the CloudGIS team (nws.mapservices@noaa.gov)

  Note: This service is not time enabled

Flood Hazard Outlook (FHO) Web Application

Area Hydrologic Discussion(AHD) Current Data

• The Office of Water Prediction's (OWP's) National Water Center (NWC) has identified an operational need for a real-time national product to discuss a variety of short and medium range (Days 1-10) observed and modeled hydrologic guidance for the United States.

  The experimental National Hydrologic Discussion (NHD) informs users of the current hydrologic conditions at the continental scale, integrates and discusses hydrologic guidance from various sources, and provides additional information on impacts to communities along streams and rivers.
  The purpose of this product is to discuss the forecast guidance and analyses for hydrologic events in the United States to form a more holistic picture of current and forecast hydrologic concerns.

  The NWS is accepting comments through July 1, 2023 on the Experimental FHO as a replacement for the current Significant River Flood Outlook product. Please provide feedback on the Experimental FHO at:

  • Link to metadata: Product Description Document Experimental National Hydrologic Discussion Product

National Hydrologic Discussion (NHD) Current Data

• NWM Streamflow Anomaly Analysis GIS Web Services

  Depicts seasonal streamflow anomalies derived from the analysis and assimilation configuration of the National Water Model (NWM) over the contiguous U.S. Anomalies are based on 7-day and 14-day moving average streamflow percentiles for each reach and the current calendar day.
  
  The NWS is accepting comments through December 31, 2022 on the Experimental NWC Visualization Services. This service is one of many Experimental NWC Visualization Services. Please provide feedback on the Experimental NWC Visualization Services at: https://www.surveymonkey.com/r/Exp_NWCVisSvcs_2022

  • Link to graphical web page: https://www.weather.gov/owp/operations
  • Link to metadata: SDD NWC VisualizationServices 2022 PDF

• NWM High Flow Magnitude Analysis GIS Web Services

  Depicts the magnitude of the National Water Model (NWM) streamflow forecast where the NWM is signaling high water. This service is derived from the analysis and assimilation configuration of the NWM over one of three spatial domains (see below). Shown are reaches with flow at or above high water thresholds. Reaches are colored by the annual exceedance probability (AEP) of their current flow

  
  
  CONUS: High water thresholds (regionally varied) and AEPs were derived using the 44-year NWM v3.0 reanalysis simulation.
  
  Hawaii: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/sir/2010/5035/sir2010-5035_text.pdf.
  
  Puerto Rico / U.S. Virgin Islands: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/wri/wri994142/pdf/wri99-4142.pdf.

• (NWM) Past 14-Day Max High Flow Magnitude Analysis GIS Web Services

  Depicts the magnitude of the peak NWM streamflow forecast over the past 14 days where the National Water Model (NWM) is signaling high water. This service is derived from the analysis and assimilation configuration of the NWM over the contiguous U.S. Shown are reaches with flow at or above high water thresholds. Reaches are colored by the annual exceedance probability (AEP) of their current flow. High water thresholds (regionally varied) and AEPs were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM 18 / 48-Hour High Water Arrival Time Forecast GIS Web Services

  Depicts the forecast arrival time of high water over the next 18 hours (CONUS) or 48 hours (Hawaii / PRVI). This service is derived from the short-range configuration of the National Water Model (NWM) over one of three spatial domains (see below). Shown are reaches that are expected to have flow at or above the high water threshold over the next 18 or 48 hours. Reaches are colored by the time at which they are forecast to reach high water.

  
  
  CONUS: High water thresholds (regionally varied) and AEPs were derived using the 44-year NWM v3.0 reanalysis simulation.
  
  Hawaii: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/sir/2010/5035/sir2010-5035_text.pdf.
  
  Puerto Rico / U.S. Virgin Islands: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/wri/wri994142/pdf/wri99-4142.pdf.

• NWM 18-Hour Rapid Onset Flooding Forecast GIS Web Services

  Depicts forecast rapid onset flooding using the short-range configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches (stream order 4 and below) with a forecast flow increase of 100% or greater within an hour, and which are expected to be at or above the high water threshold within 6 hours of that increase. Also shown are USGS HUC10 polygons symbolized by the percentage of NWM waterway length (within each HUC10) that is expected to meet the previously mentioned criteria. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM 12-Hour Rapid Onset Flooding Probability Forecast GIS Web Services

  Depicts the probability of forecast rapid onset flooding over the next 12 hours using a time-lagged ensemble from the short-range configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches (stream order 4 and below) that are expected to meet rapid onset flooding criteria (flow increase of 100% or greater within one hour and high water threshold conditions within 6 hours) using the most recent 7 forecasts. Reaches are colored by the probability that they will meet or exceed rapid onset conditions within hours 1-6, 7-12, and 1-12. Probabilities are computed as the % agreement across the 7 ensemble members that a given reach will meet rapid onset criteria at some point during the time period of interest. Hotspots show the average 1-12 hour rapid onset flooding probability, weighted by reach length, for USGS HUC10 basins with greater than 10% of NWM feature length meeting rapid onset criteria in the next 12 hours. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM 12-Hour Max High Water Probability Forecast GIS Web Services

  Depicts the probability of forecast high water over the next 12 hours using a time-lagged ensemble from the short-range forecast of the National Water Model (NWM) over the contiguous U.S. Shown are reaches that are forecast to have flow at or above high water within the next 12 hours of at least one of the last 7 forecasts. Reaches are colored by the probability that they will meet or exceed the high water threshold across the last 7 forecasts. Probabilities are derived by counting the number of forecasts that meet the high water condition within the next 12 hours, equally weighted. Also shown are USGS HUC10 polygons for basins with greater than 50% of NWM features with flow expected to be at or above high water over the next 12 hours, symbolized by the average probability. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM 18 / 48-Hour Max High Flow Magnitude Forecast GIS Web Services

  Depicts the magnitude of the peak National Water Model (NWM) streamflow forecast over the next 18 hours (CONUS) or 48 hours (Hawaii / PRVI) where the NWM is signaling high water. This service is derived from the short-range configuration of the NWM over one of three spatial domains (see below). Shown are reaches with peak flow at or above high water thresholds. Reaches are colored by the annual exceedance probability (AEP) of their forecast peak flow.

  
  
  CONUS: High water thresholds (regionally varied) and AEPs were derived using the 44-year NWM v3.0 reanalysis simulation.
  
  Hawaii: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/sir/2010/5035/sir2010-5035_text.pdf.
  
  Puerto Rico / U.S. Virgin Islands: High water thresholds and AEPs were derived from USGS regression equations found at https://pubs.usgs.gov/wri/wri994142/pdf/wri99-4142.pdf.

• NWM GFS 10-Day High Water Arrival Time Forecast GIS Web Services

  Depicts the forecast arrival time of high water over the next 10 days. This service is derived from the GFS medium-range configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches that are expected to have flow at or above the high water threshold over the next 10 days. Reaches are colored by the time at which they are forecast to reach high water (calculated in 3 hour increments). High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM GFS 5-Day High Water Probability Forecast GIS Web Services

  Depicts the probability of forecast high water over the next 5 days using ensembles from the medium-range GFS configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches that are expected to have flow at or above high water on Day 1, Day 2, Day 3, and Days 4-5, using the 6 time-lagged ensemble members of the medium-range forecast. Reaches are colored by the probability that they will meet or exceed the high water threshold on Day 1, Day 2, Day 3, and Days 4-5. Probabilities are computed as the % agreement across the 6 time-lagged ensemble members, equally weighted. Also shown are USGS HUC8 polygons for basins with greater than 50% of NWM features with flow expected to be at or above high water over the next 5 days, symbolized by the average probability. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM GFS 10-Day Max High Flow Magnitude Forecast

  Depicts the magnitude of the peak National Water Model (NWM) streamflow forecast over the next 3, 5 and 10 days where the NWM is signaling high water. This service is derived from the medium-range GFS configuration of the NWM over the contiguous U.S. Shown are reaches with peak flow at or above high water thresholds. Reaches are colored by the annual exceedance probability (AEP) of their forecast peak flow. High water thresholds (regionally varied) and AEPs were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM GFS 10-Day Rapid Onset Flooding Forecast GIS Web Services

  Depicts forecast rapid onset flooding using the medium-range configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches (stream order 4 and below) with a forecast flow increase of 100% or greater within 3 hours, and which are expected to be at or above the high water threshold within 6 hours of that increase (all calculated in 3 hour increments). Also shown are USGS HUC08 polygons symbolized by the percentage of NWM waterway length (within each HUC08) that is expected to meet the previously mentioned criteria. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM GFS 5-Day Rapid Onset Flooding Probability Forecast GIS Web Services

  Depicts the probability of forecast rapid onset flooding over the next 5 days using ensembles from the medium-range GFS configuration of the National Water Model (NWM) over the contiguous U.S. Shown are reaches that are expected to have flow at or above high water thresholds on Day 1, Day 2, Day 3, Days 4-5, and Days 1-5 using the 6 time-lagged ensemble members of the medium-range forecast. Reaches are colored by the probability that they will meet or exceed rapid onset conditions on Day 1, Day 2, Day 3, Days 4-5, and Days 1-5. Probabilities are computed as the % agreement across the 6 time-lagged ensemble members, equally weighted. Hotspots show average 1-5 day rapid onset flooding probability, weighted by reach length, for USGS HUC8 basins with greater than 10% of NWM feature length meeting rapid onset criteria in the next 5 days. High water thresholds (regionally varied) were derived using the 44-year NWM v3.0 reanalysis simulation.

• NWM Soil Moisture GIS Web Services

  Depicts estimated near surface soil moisture. This service is built by processing the analysis assimilation output of the National Water Model land based data. All outputs of the land dataset have the same geospatial extent covering all of CONUS with partial coverage into Canada and Mexico. Currently, the only layer within the service is near-surface soil moisture saturation. The near-surface soil moisture saturation layer shows moisture saturation of the top 40cm of the soil. Model Output Version: v3.0