SNODAS Daily SWE and Snow Coverage Statistics

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Daily SNODAS Snowpack Products for Colorado Water Supply Basins

This website provides access to a historical archive of SNODAS data products for Colorado water supply basins. Snow Data Assimilation System (SNODAS) data from the National Operational Hydrologic Remote Sensing Center (NOHRSC) are processed daily to calculate Snow Water Equivalent (SWE) and Snow Coverage statistics for water supply basins in Colorado. Snow Water Equivalent is the estimate of the depth of liquid water contained within the snowpack. Snow coverage is a percent of the basin land surface covered by snow (water bodies in the basin are ignored). The national SNODAS gridded dataset has been processed to provide data products for Colorado. Mean SWE is displayed in the map using a legend similar to the National Weather Service. The SNODAS Tools website provides access to an archive of daily products.

The website is best viewed on a widescreen display. If the layout does not clearly show a left panel with tabs, a center panel with map, and a right panel with date and basin selectors, try maximizing to fill the display. Ctrl and minus can be used to zoom out until the layout shows all components.
Hover over a basin to see the daily mean SWE value and other daily statistics.
Use the Select Date button to display historical data for a specified day.
Enter animation start and end dates, press Submit, and then press the play button to view the animation of daily SWE data.
Click on a basin in the map to select the basin or use the Select Basin to select from the basin list. Then click on buttons in the lower right to display graphs.
Once a graph has been opened, click anywhere on the screen to close the graph view and return to the main screen.
Reposition the map by holding the mouse button down and dragging.
Zoom in and out of the map using the control in the upper left, or use the mouse wheel.
Use the Data tab on the left to access data files.

Development of the SNODAS Tools was funded by the Colorado Water Conservation Board. The tools were developed by the Open Water Foundation. Project resources are available on the OWF SNODAS project website.

Contact: Joe Busto, joe.busto@state.co.us

Steve Malers, steve.malers@openwaterfoundation.org

Website version 1.0.9 (2017-08-28)

The national SNODAS data are available from the Snow Data Assimilation System (SNODAS) and can be viewed at National Operational Hydrologic Remote Sensing Center (NOHRSC). The SNODAS data are processed into statistical data products by the CDSS SNODAS Tools.

Daily Data

The output consists of comma-separated-value (CSV) files ByDate (basin data for each day) and ByBasin (historical period for each basin). Data files can be downloaded by accessing the following URL resources. The zip file contains a shapefile with daily statistics in the attribute table (attribute names have been truncated to adhere to shapefile limit).

Upstream Total Data Products

Static Data Available for Download

(State of Colorado rectangular boundary)

(basin boundaries, same as daily boundaries)

StaticData/SNODAS_CO_BasinBoundaries.zip (input basin boundary layer shapefile)

StaticData/Watershed_Connectivity_v4.xlsx (input basin connectivity for total basin calculations)

Refer to the SNODAS Tools User Manual and SNODAS Tools Developer Manual for more information.

SNODAS data citation: National Operational Hydrologic Remote Sensing Center. 2004. Snow Data Assimilation System (SNODAS) Data Products at NSIDC, Version 1. SWE dataset. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5TB14TC. Data are accessed daily, and historical period is also accessed as needed for historical period products.

SNODAS Animation

Increment (days): (Default is set to 1)