Quoted from: http://www.appsolutelydigital.com/ModelPrimer/chapter5_section7.html

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

• 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.

Limitations

• Certain air temperature related biases do not overcome.
• Requires basin knowledge in assigning values for some parameters
• Does not have graphical user interface (GUI)

Additional Information

Anderson, E.A., 1973, National Weather Service River Forecast System-Snow Accumulation and Ablation Model, NOAA Technical Memorandum: NWS Hydro-17, US National Weather Service
Anderson, E. 2006. Snow Accumulation and Ablation Model -- SNOW-17
Franz et al., 2008, Operational snow modeling: Addressing the challenges of an energy balance model for National Weather Service forecasts, Journal of Hydrology