THE LEADING OBJECTIVE OF THIS STUDY IS THE EVALUATION OF REMOTE SENSING SNOWFALL ESTIMATE IN CONJUNCTION WITH THE GPM VALIDATION NETWORK (VN) AND SATELLITE-BASED ESTIMATES. THE VN CONSISTS OF 70 NATIONAL WEATHER SERVICE (NWS) DUAL-POLARIZATION RADARS AND SEVERAL RESEARCH RADARS AND THE RADAR PRECIPITATION ESTIMATE WAS CONSTRUCTED DURING GPM CORE OBSERVATORY OVERPASSES AND IS USED AS A SATELLITE VALIDATION PRODUCT. THIS STUDY WILL GENERATE ACCOMPANYING TIME SERIES OF "GROUND TRUTH" PRECIPITATION RATES FROM NWS AUTOMATED SURFACE OBSERVING STATIONS (ASOS) IN THE PRESENCE OF SNOWFALL FOR COMPARISON TO VN AND GPM ESTIMATES. THE PHASE OF THE PRECIPITATION WILL BE DETERMINED THROUGH ASOS PRESENT WEATHER SENSORS. THE STUDY ALSO INCLUDES TWO GPM GROUND VALIDATION RESEARCH FACILITY AT MARQUETTE MICHIGAN (MQT) AND WALLOPS ISLAND VIRGINIA (WFF). THE FORMER SITE INCLUDES A VERTICALLY POINTING MICRO RAIN RADAR PRECIPITATION IMAGING PACKAGE AND AUTONOMOUS PARSIVEL UNIT IN ADDITION TO A PLUVIO GAUGE. THE LATTER SITE ALSO INCLUDES ADDITIONAL RESOURCES INCLUDING TWO DIMENSIONAL VIDEO DISDROMETERS. THE ADVANTAGE OF FORMER SITE IS THE PRESENCE OF ABUNDANT WINTER PRECIPITATION. THE ADVANTAGE OF SECOND SITE IS THE PRESENCE OF MIXED PRECIPITATION AND NEARBY ASOS SITE. THESE TWO RESEARCH FACILITIES PROVIDE CRUCIAL DATABASES TO EVALUATE THE PERFORMANCE OF ASOS BASED PRECIPITATION PHASE AND ESTIMATED SNOWFALL. THE STUDY WILL ALSO BENEFIT FROM EXTENSIVE FIELD CAMPAIGN DATABASES IN SOUTH KOREA AND SOUTHERN ONTARIO CANADA.