Navigating the NWS River Level Viewer: A Comprehensive Guide

The National Weather Service (NWS) River Level Viewer is an indispensable tool for monitoring river conditions and staying informed about potential flooding risks. This easy-to-use platform provides real-time data on river levels, forecasts, and historical information. Understanding how to navigate the viewer will empower you to make informed decisions about your safety and property.

Accessing the NWS River Level Viewer

To access the River Level Viewer, visit the NWS website at www.weather.gov/river. Alternatively, you can directly visit: https://water.weather.gov/ahps2/index.php?wfo=all

Understanding the Interface

The viewer's interface is designed to be user-friendly and intuitive. The main navigation menu, located at the top of the page, offers quick access to various features:

Map: This interactive map displays river levels and forecasts across the country.
Sites: This section provides a list of all gauging stations, which are used to monitor river levels.
Forecasts: View predicted river levels for specific gauging stations.
Hydrographs: Visualize historical and real-time river level data in a graph format.

Using the Map View

The map view is a convenient way to visualize river levels in your area or anywhere in the country.

Zoom In/Out: Use the zoom buttons or your mouse to adjust the map's scale.
Pan: Click and drag the map to move it around.
Legend: The legend in the upper right corner explains the colors and symbols used to represent river levels.
Gauge Locations: Gauging stations are represented by small circles on the map. Hover over a circle to view the station's name and real-time river level.
River Basins: The map is divided into different river basins, which are grouped by color. Click on a basin to view a list of gauging stations within that area.

Exploring the Sites Section

The Sites section lists all the gauging stations in the NWS database.

Filter: Use the search bar to filter stations by name, state, or county.
Stations: Click on a station name to view detailed information, including its location, current river level, forecast, and hydrograph.
View Map: Toggle the map view to display the location of the selected station.

Understanding River Level Forecasts

The Forecasts section provides predicted river levels for specific gauging stations.

Time: Select a specific time or date to view the forecast for that period.
Forecast: The forecast table displays predicted river levels at specific intervals (e.g., every 6 hours).
Confidence: The confidence indicator shows the probability that the forecast will be accurate.
Legend: The legend explains the color-coded categories used to indicate the severity of potential flooding:
- Minor Flooding: Light blue
- Moderate Flooding: Yellow
- Major Flooding: Orange
- Record Flooding: Red

Visualizing River Level Data with Hydrographs

Hydrographs provide a graphical representation of historical and real-time river level data.

Timespan: Select a timespan from the drop-down menu to view data for a specific period.
Data: The graph displays the river level over time.
Thresholds: The graph also shows threshold lines for various flood stages (e.g., action stage, flood stage).
Click and Drag: Click and drag a section of the graph to zoom in on a specific time period.

Additional Features

Gauge Status: View the status of a gauging station (e.g., operational, out of service).
Notifications: Set up notifications to receive alerts when river levels reach a specific threshold.
Data Export: Download river level data in various formats (e.g., CSV, JSON).
Glossary: Access definitions of technical terms used in the viewer.

Conclusion

The NWS River Level Viewer is a valuable resource for monitoring river conditions, staying informed about potential flooding risks, and making informed decisions about your safety and property. By understanding how to navigate the viewer's interface and utilize its various features, you can stay prepared and mitigate the impact of flooding events.