IMPACTS WILL DETERMINE HOW MULTI-SCALE DYNAMICAL AND MICROPHYSICAL PROCESSES IN WINTER STORMS INTERACT TO PRODUCE BANDED REGIONS OF SNOWFALL AND WILL PROVIDE KNOWLEDGE THAT INFORMS REMOTE SENSING OF SNOW FROM SPACE AND IMPROVES US STORM PREDICTION CAPABILITIES. A KEY GPM OBJECTIVE IS TO DETECT AND MEASURE FALLING SNOW AT THE SURFACE OVER A WIDE RANGE OF SNOWFALL INTENSITIES. THE CURRENT GPM ALGORITHMS ARE LIMITED BY RATHER LARGE UNCERTAINTIES IN SNOW AMOUNT [SKOFRONICK-JACKSON ET AL. 2017]. INTERPRETATION OF RETRIEVAL FROM AND VALIDATION OF GPM DUAL-FREQUENCY PRECIPITATION RADAR (DPR) AND GPM MICROWAVE IMAGER (GMI) DATA FOR ALL RANGES OF SNOWFALL INTENSITY REQUIRES AN UNDERSTANDING OF THE RELATIONSHIPS BETWEEN SNOWSTORM VERTICAL REFLECTIVITY STRUCTURE PARTICLE CHARACTERISTICS AND PASSIVE MICROWAVE BRIGHTNESS TEMPERATURES. IMPACTS WILL PROVIDE ESSENTIAL DATA ABOUT THESE RELATIONSHIPS FOR DETERMINING GMI AND DPR SENSITIVITY THRESHOLDS TO FALLING-SNOW DETECTION AND MEASUREMENT THAT WILL IMPROVE GPM SNOW ESTIMATES AND REDUCE THEIR UNCERTAINTY. IMPACTS DATA CAN ALSO BE USED TO ESTIMATE THE UPPER LIMIT OF SNOWFALL RATES FROM CLOUD- SAT (USING THE EXISTING CLOUDSAT DATA SET AND MULTI-FREQUENCY RADARS ON THE ER-2). WITH RADAR SENSITIVITY DOWN TO 28 DBZ CLOUDSAT CAN ESTIMATE VERY LIGHT SNOWFALL RATES BUT STRONGLY ATTENUATES IN RAIN AND SATURATES ABOVE ~20 DBZ DUE PRIMARILY TO MIE SCATTERING. IMPACTS WILL PROVIDE AN OPPORTUNITY TO DETERMINE THE VALID RANGES FOR SNOW MEASUREMENTS FROM BOTH GPM AND CLOUDSAT IMPROVING THE USE OF THE SATELLITE DATA IN PRODUCING ACCURATE GLOBAL SNOWFALL MAPS FOR DETERMINING WATER RESOURCES IN THE FORM OF FALLING SNOW. THE CLOUD CONVECTION AND PRECIPITATION (CCP) TARGETED OBSERVABLE DESIGNATED-PROGRAM RECOMMENDATION BY THE NATIONAL ACADEMIES AS PART OF THE 2017 NASA EARTH SCIENCE DECADAL SURVEY SEEKS TO ADDRESS HOW WE CAN BETTER UNDERSTAND AND PREDICT COUPLED CLOUD AND PRECIPITATION VARIABILITY AND CHANGE. THE MISSION CONCEPT INCLUDES A COMBINATION OF MULTIPLE-FREQUENCY RADAR (E.G. KA W) WITH POSSIBLE DOPPLER CAPABILITY AND MULTI-FREQUENCY PASSIVE MICROWAVE TO JOINTLY STUDY CLOUD AND PRECIPITATION PROCESSES AROUND THE GLOBE. IMPACTS PROPOSED ER-2 INSTRUMENT SUITE IS IDEALLY SUITED FOR DEVELOPING POTENTIAL MISSION DESIGNS FOR CCP. IMPACTS MULTI-SENSOR ACTIVE AND PASSIVE MEASUREMENTS ALONG WITH IN-SITU MICROPHYSICAL MEASUREMENTS WILL HELP INFORM DEVELOPMENT OF FUTURE SATELLITE MISSIONS FOR MEASURING CLOUDS AND PRECIPITATION FROM SPACE.