Advanced Hydrologic Prediction Service (AHPS) River Gauge data
National Weather Service (NWS) Advanced Hydrologic Prediction Service (AHPS)
The Advanced Hydrologic Prediction System (AHPS) is a web-based suite of accurate and information-rich forecast products, including river stage observations and forecasts. These products display the magnitude and uncertainty of occurrence of floods or droughts, from hours to days and months, in advance. An interactive map allows users to view current observations and forecasts.
The majority of the observed water level data displayed on the AHPS web pages originates from the U.S. Geological Survey's (USGS) National Streamflow Information Program which maintains a national network of streamgages. In addition, real-time water level information is collected from other federal, state, and local streamgage networks.
AHPS River Forecast data provide valuable information about the chances of flood occurring. These river stage/flow forecasts show the maximum forecast flood category, taking into account past precipitation and the precipitation amounts expected approximately 48 hours into the future from the forecast issuance time.
AHPS river forecast data are available in a GIS format from the National Weather Service.
| Value | Map Hex Color |
|---|---|
| Major Flooding | #cc33ff |
| Moderate Flooding | #ff0000 |
| Minor Flooding | #ff9900 |
| Near Flood Stage | #ffff00 |
| No Flooding | #01ff00 |
| Flood Category Not Defined | #72afe9 |
| At or Below Low Water Threshold | #906320 |
| Forecasts Are Not Current | #bdc2bb |
| No Forecast Within This Timeframe | #8c8c8c |
| Out of Service | #666666 |
How to
- Use the tabs at the top to toggle between current “River Observations,” “River Forecasts,” and more
- Use the mouse and plus or minus to navigate around the map
- Select a station to see a time-series graph of that particular station
- Under “River Forecasts”, use the sliding bar at the top to see forecasts for particular days
- Select “Download” to download the visible area or selected station in various formats
Access
AHPS Interactive Map: view current and forecasted stream levels as well as magnitude and likelihood of flooding for the United States
AHPS Downloads: link to AHPS Shapefiles and KMZ Data
Documentation
Helpful links to general information, specific technical instructions, and referenced articles related to this dataset.
