HEC-HMS Technical Reference Manual Snow Accumulation and Melt Current: Available Snow Accumulation and Melt Methods PDF Download PDF Download page Available Snow Accumulation and Melt Methods. Current page All pages Available Snow Accumulation and Melt Methods Five snow accumulation and melt methods are available for use within HEC-HMS. These methods include:Temperature Index MethodGridded Temperature Index MethodHybrid SnowEnergy Budget MethodGridded Energy Budget MethodThe following sections detail their unique concepts and uses. ×