Purpose: Models quantity and flow of snow from snow cover.
Developer: US National Weather Service (NWS)
Key Features: Uses only two input variables, i.e., air temperature and precipitation; Open-source
Latest Release: 2015, Version 5.1.007
OS Platform: Windows
Cost: Free
Related Software: Snow–Atmosphere–Soil Transfer (SAST) model


National Weather Service (NWS) SNOW-17, first developed in 1973 is a conceptual model, that it is used to estimate the amount snow accumulation and snowmelt discharge. Calculations are based on snow energy balance that account for snowpack accumulation, heat exchange between the snow and ambient air temperature, snow cover extent, heat storage and exchange, and water retention or transmission.

The Snow-17 model key feature is that the program requirements only require two inputs: air temperature and precipitation. For river forecasting, the output from the SNOW-17 is coupled with a rainfall-runoff model such as Sacramento - Soil Moisture Accounting. SNOW-17 is part of the National Weather Service River Forecast System (NWSRFS), which is an official operational forecasting system for the entire U.S.

Advantages and Limitations

Advantages Limitations
  • A simple model, all calculations are chiefly driven by air temperature
  • The model can be run at multiple intervals of day (e.g., 2-, 4-hr).
  • The model code is in the public domain, and has been widely used in the scientific community
  • The model has been used operationally for decades in the U.S.
  • Studies shown the better performance of the Snow-17 compared to more complex snowmelt models.
  • Certain air temperature related biases do not overcome.
  • Requires basin knowledge in assigning values for some parameters
  • Does not have graphical user interface (GUI)

Illustrative Screens

Sample Applications

Africa East Asia and the Pacific Europe & Central Asia Latin America & the Caribbean Middle East and North Africa South Asia

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