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National Water and Climate Center


Google Earth Water Supply Forecast Layer

View NRCS water supply forecasts in the rich 3-dimensional visual context of Google Earth.

Building upon the interactive visualization of SNOTEL snowpack and precipitation information, this complementary layer displays hydrologic outlooks produced cooperatively by the NRCS and National Weather Service (NWS). Opening the data layer below in the Google Earth application opens a window to the data that allows you to have a birds-eye view of the Western US, while zooming in to individual basins and gages of interest.

Quick Start Guide:

1) Google Earth is an application requiring a fast internet connection and a modern computer. Be sure to check if your system matches the requirements outlined by Google.

2) Download and install the Google Earth application. If you have any problems, the Google Earth Support webpage is full of useful information. Do note that alternatives to Google Earth exist, such as NASA's WorldWind and ESRI's ArcExplorer, both of which are free.

3) Load the water supply forecast ".kmz" data file from the link below. The application may automatically launch on opening the file.

Link to Latest Forecasts

Screenshot of Google Earth Water Supply Forecast Layer

4) Browse around or zoom into your basin of interest. Click individual sites for more info, both on the map and in the "Places" frame on the left. Use the "Places" frame to find a specific water supply forecast, organized by hydrologic region.

5) Any day you use this application, come to this webpage and click on the above links to the data files.  Important!  If you save the “.kmz” file locally to your computer, it will only contain the data from the day you acquired it and will not automatically refresh. To ensure you have the latest data, always come back to this webpage. Text at the bottom of the window that appears on clicking a station will indicate both the nominal issue date of the forecast, the creation of the forecast data file and the date the kml file, itself, was created.

A Note About Precision:

Most of the location information of the gages is obtained from the US Geologic Survey whereas others comes from NRCS records. Often, reservoir inflow forecasts are displayed at the outlet of the dam. No guarantee is made on the accuracy of the location of the gages. However, if you are aware that a station is displayed in the wrong location, you are encouraged to contact the content manager of this page.

A Note About the Data:

This data comes from an automated processing of the operational forecast archive of the NRCS National Water and Climate Center hydrologists. The values in the files are generally considered to be identical to the official published forecasts, although there is no guarantee associated with this data and the State Water Supply Outlook Reports remain the official source of the forecasts. If a value appears in this file and not the Outlook Reports, it is likely unintentional and the value in this file should be disregarded. These values are subject to change, especially the most recent file during the first month of its existence.

More Information:

These files are updated aperiodically as the forecasts are finalized and published by various agencies, typically less than 7 days after the nominal issue date of the forecast. The symbols are color-coded by the 50% exceedence value of the forecast as percent of the 1981-2010 normal. This value does not necessarily represent the full character of the forecast, such as its uncertainty. It is important to consider all of the exceedence levels associated with the forecasts if you plan on using this product to manage risk.

Clicking on a symbol will reveal additional information, including details about the forecasts, and links to additional reports and web pages.

Stations are organized in the “Places” tab by hydrologic region. Click on the check box to turn on or off the viewing of individual sites or entire regions. The top folder also allows the addition (or removal) of the NRCS logo and legend.

Screenshot of "Places" tab

If you find this product useful or have any suggestions, please don’t hesitate in contacting us!  For additional Google Earth data, also see the NRCS SNOTEL webpage.

Content Manager:

Cara McCarthy