Snowcast Showdown: Development Stage

Seasonal snowpack is a critical water resource throughout the Western U.S. Help the Bureau of Reclamation estimate snow water equivalent (SWE) at a high spatiotemporal resolution using near real-time data sources. #climate

mar 2022
1,064 joined

About the project


View of a SNOTEL site from U.S. Climate Resilience Toolkit.

This challenge uses remote sensing data, manual snow measurements, and climate information to estimate SWE at a high spatiotemporal resolution. New and improved SWE estimates built upon existing ground, air, and space-based technologies will improve water supply forecasts, helping reservoir operators to manage limited water supplies and respond to extreme weather events.

Ground-based measurements of SWE

Ground-based methods measure snow in a single location or in a small area. Most ground-based methods use basic technologies like a stick or tube to physically measure snow depth. While these measures are considered highly accurate, they typically require a person to visit a location that may be difficult to access on a regular basis. For over 80 years, a network of in situ instruments managed by the Natural Resources Conservation Service (NRCS) called snow courses have been used to monitor snowpacks.

In the late 1970s, manually measured snow courses were augmented by automated snow and weather stations (most notably the NRCS SNOTEL stations network). SNOTEL stations measure SWE using a technology called a snow pillow, which uses a flexible bladder filled with antifreeze to convert fluid pressure into weight. These stations provide continuous readings throughout the snow accumulation and runoff seasons, but are spatially limited and can face challenging maintenance issues. Volunteer networks of weather observers around the US help to supplement this data using low-cost tools to map and measure precipitation.

Air and space-based measurements of SWE

The Airborne Snow Observatory (ASO) methodology, developed at NASA’s Jet Propulsion Laboratory (JPL) and now commercially available (ASO, Inc.) uses an aircraft-based imaging spectrometer to measure differences between snow-covered and snow-free surfaces. ASO combines lidar-derived snow depth with albedo estimates to model SWE at a high level of accuracy, though flight timing and coverage is not guaranteed.

Polar-orbiting sensors have become invaluable for monitoring seasonal snowpack because they provide rich information where ground measures are unavailable. Remote sensing techniques derive characteristics of snowpack by measuring the spectral signature, or reflectance and variation, of electromagnetic radiation. Per-pixel snow coverage, or fractional snow-covered area (fSCA), is an important snow measure that can be retrieved from multispectral satellite imagery. Despite the many advantages of satellite data, corrections are required in shallow snowpack, forested areas, and complex terrain. For more information on space-based remote sensing for snow monitoring, we suggest checking out this helpful journal article.

About the Bureau of Reclamation

Reclamation employees deliver reliable water and hydropower for the western United States.

Established in 1902, the Bureau of Reclamation (Reclamation) is best known for the dams, power plants, and canals it constructed in the 17 Western U.S. states. These water projects led to homesteading and promoted the economic development of the West. Reclamation has constructed more than 600 dams and reservoirs including Hoover Dam on the Colorado River and Grand Coulee on the Columbia River.

Today, Reclamation is the largest wholesaler of water in the country. It brings water to more than 31 million people, and provides one out of five Western farmers (140,000) with irrigation water for 10 million acres of farmland that produce 60% of the nation's vegetables and 25% of its fruits and nuts. Reclamation is also the second largest producer of hydroelectric power in the US. Its 53 power plants annually provide more than 40 billion kilowatt hours generating nearly a billion dollars in power revenues and produce enough electricity to serve 3.5 million homes.

Reclamation is a water management agency with a Strategic Plan outlining numerous programs, initiatives and activities that will help the Western U.S. meet new water needs and balance the multitude of competing uses of water in the West. Its mission is to assist in meeting the increasing water demands of the West while protecting the environment and the public’s investment in these structures. Reclamation emphasizes fulfilling water delivery, water conservation, water recycling and reuse, and finding ways to bring together interests to address the competing needs for limited water resources.

Reclamation operates and maintains water and power projects in 17 Western U.S. states:

You can learn more here: