IT IS CRITICAL TO ACCURATELY MODEL BOTH THE TIMING AND MAGNITUDE OF SNOWMELT IN THE WESTERN US WHERE MELT OF THE SEASONAL MOUNTAIN SNOWPACK DOMINATES REGIONAL HYDROLOGY POPULATIONS ARE INCREASING AND SNOW MELT PATTERNS ARE SHIFTING. IN MANY SNOW DOMINATED WATERSHEDS OPERATIONAL RUNOFF MODELING METHODS RELY ON TEMPERATURE INDEX MODELS THAT ARE CALIBRATED RELATIONSHIPS BETWEEN AIR TEMPERATURE AND SNOWMELT. SNOWMELT RATES AND RESULTING HYDROGRAPHS THOUGH ARE PREDOMINANTLY CONTROLLED BY NET SOLAR AND LONGWAVE RADIATION WHICH ARE DEPENDENT ON THE FRACTIONAL COVER OF SNOW SURFACE ALBEDO AND ATMOSPHERIC CONDITIONS. THE COLORADO BASIN FORECAST CENTER (CBRFC) USES THE SNOW-17 ACCUMULATION AND ABLATION MODEL OPERATIONALLY; A SINGLE LAYER MODEL THAT HAS A CALIBRATED TEMPERATURE INDEX MELT FACTOR AND REQUIRES ONLY INPUTS OF TEMPERATURE AND PRECIPITATION. THE MELT INDEX AND MODEL EFFECTIVENESS IS DIMINISHED WHEN CONDITIONS ARE OUTSIDE THE CALIBRATION PERIOD AND ARE ESPECIALLY PRONOUNCED DURING DUST ON SNOW EVENTS. RECENT WORK HAS ESTABLISHED THE IMPORTANT ROLE OF DUST DEPOSITION ON SNOW IN THE UPPER COLORADO RIVER BASIN WHERE RADIATIVE FORCING BY DUST HAS BEEN SHOWN TO SHIFT SNOWMELT TIMING AND MAGNITUDE AND HAS BEEN CORRELATED TO FORECASTING ERRORS FROM SNOW-17. THE CBRFC HAS BEEN WORKING TO INCORPORATE RETRIEVALS FROM THE MODIS DUST RADIATIVE FORCING IN SNOW (MODDRFS) IN THEIR OPERATIONAL FORECASTING BY MANUALLY APPLYING A MELT FACTOR CORRECTION OR MODIFYING THE AIR TEMPERATURE FORCINGS. THIS METHODOLOGY WHICH IS TIME INTENSIVE AND STRONGLY DEPENDENT ON FORECASTER KNOWLEDGE DOES NOT EXPLICITLY ACCOUNT FOR THE PERTURBATION TO NET RADIATION. THIS PROPOSAL DIRECTLY ADDRESSES THE LIMITATIONS OF OPERATIONAL TEMPERATURE INDEX MODELING IN THE COLORADO RIVER BASIN BY DEVELOPING THE CAPACITY AT THE CBRFC TO RUN A SPATIALLY DISTRIBUTED SNOW ENERGY BALANCE MODEL AND ASSESS OUTPUTS TO ENHANCE OPERATIONAL DECISION MAKING. THE ABILITY TO RUN ANY ENERGY BALANCE MODEL OVER THE SNOW DOMINATED HEADWATERS OF THE COLORADO RIVER IS CURRENTLY LIMITED BY THE LACK OF LOCAL AND RELEVANT ENERGY BALANCE INFORMATION FROM IN-SITU OBSERVATION NETWORKS. WE PROPOSE TO ADDRESS THE DATA LIMITATION BY ASSIMILATING REMOTE SENSING IMAGERY (MODIS VIIRS GOES) TO INFORM NET RADIATION AND ATMOSPHERIC MODELS (HRRR WRF) TO INFORM METEOROLOGICAL VARIABLES. THE MODEL WILL BE VALIDATED OVER WELL INSTRUMENTED SNOW ENERGY BALANCE STUDY BASINS AND WITH MULTIYEAR HIGH RESOLUTION MAPS OF SNOW DEPTH WATER EQUIVALENT AND ALBEDO FROM NASA S AIRBORNE SNOW OBSERVATORY. THE PROJECT A JOINT EFFORT BETWEEN THE CBRFC USDA ARS NORTHWEST WATERSHED RESEARCH CENTER AND UNIVERSITY OF UTAH SNOW HYDROLOGY GROUP AIMS TO FILL THE GAPS BETWEEN SPARSE IN SITU OBSERVATION NETWORK AND PRODUCE REALISTIC MAPS OF SNOW COVERED AREA SNOW WATER EQUIVALENT AND STREAMFLOW. AT THE COMPLETION OF THIS PROJECT THERE WILL BE SUCCESSFUL TECHNOLOGY TRANSFER TO THE COLORADO BASIN RIVER FORECAST CENTER. THE SUSTAINABLE INCORPORATION OF PHYSICALLY BASED SNOW ENERGY BALANCE MODELING INFORMED BY REMOTE SENSING INTO THE CBRFC DECISION MAKING PROCESS WILL PROVIDE A MORE PHYSICALLY-COMPLETE DESCRIPTION OF THE FACTORS THAT REGIONALLY AND SEASONALLY INFLUENCE SNOW NET RADIATION ENERGY BALANCE AND MELT RATES AND THEREFORE IMPROVED SNOWMELT FORECASTS IN SNOWMELT DOMINATED WATERSHEDS IN THE COLORADO RIVER BASIN. THIS IS IMPORTANT SOCIETAL IMPLICATIONS FOR IMPROVING RUNOFF FORECASTING AND SUSTAINING WATER SECURITY FOR URBAN AGRICULTURE AND RECREATIONAL COMMUNITIES IN A SNOW DOMINATED REGION.