THE FOCUS IN THIS PROPOSAL IS POST-FIELD SUPPORT RELATED TO 20-VIDEO DISDROMETER DATA COLLECTED DURING GCPEX COORDINATED WITH DATA FROM THE C-BAND KING CITY RADAR THEPOSS AND PVI INSTRUMENTS AND THE PLUVIO SNOW MEASUREMENTS. THE SNOW MEASURING INSTRUMENTS ARE SITED WITHIN 5 CLUSTERS WITH THE MAIN CLUSTER AT THE CARE SITE 3 CLUSTERS CLOSE TO CARE AND THE 5TH CLUSTER AT CONSIDERABLE DISTANCE FROM CARE (HURONIA SITE). WITH THE 2DVD AND PLUVIO INSTRUMENTS SITED WITHIN A DFIR WIND SHIELD THE WIND INDUCED ERRORS IN SNOW MEASUREMENTS SHOULD BE GREATLY REDUCED AS COMPARED WITH PAST FIELD CAMPAIGNS SUCH AS C3VP AND LPVEX LEADING TO HIGH QUALITY DATASETS WHICH CAN BE USED TO ADDRESS THE VARIABILITY OF ZE-SR RELATIONS WITHIN A SINGLE EVENT AS WELL AS FROM EVENT-TO-EVENT. FROM A GV POINT OF VIEW WE WILL ADDRESS THE KEY FACTORS THAT CONTROL THE VARIABILITY OF ZE-SR RELATIONS.OUR SECOND FOCUS IS ON STANDARDIZING OUR METHOD OF ABSOLUTE CALIBRATION OF THE NPOL RADAR (FROM END-USER PERSPECTIVE) USING 2DVD MEASUREMENTS FROM IFLOODS. WE PROPOSE TO CHECK OUR CALIBRATION OFFSETS WITH THOSE DERIVED BY DAVID WOLFF AND COLLEAGUES AT WALLOPS. WE WILL GENERATE POL-BASED RAIN ACCUMULATION MAPS AND COMPARE WITH AVAILABLE GAUGES.OUR THIRD FOCUS IS TO VALIDATE OUR CONVECTIVE-STRATIFORM-MIXED RAIN TYPE CLASSIFICATION USING THE 2DVO-RETRIEVED DSD PARAMETERS (DO NW) IN DIFFERENT CLIMATIC REGIONS I.E. GCPEX MC3E LPVEX C3VP AND IFLOODS CAMPAIGNS. PROFILERS OR MRR DATA AND NPOL DATA WILL BE USED FOR TESTING AND VALIDATING THE CLASSIFICATION SCHEME. OUR ANALYSIS LEADS NATURALLY TO REPEATING THE WILLIAMS ET AL. (2014) PROCEDURE OF ESTIMATING THE MEAN AND STANDARD DEVIATION OF THE NORMALIZED SPECTRAL WIDTH (AM' = OM DM- ) SEPARATELY FOR STRATIFORM AND CONVECTIVE RAIN (HERE DM IS THE MASS-WEIGHTED MEAN DIAMETER AND J3 IS CONSTANT). THE QUESTION IS IF THE JOINT PDF(DM ) IS DIFFERENT FOR STRATIFORM VERSUS CONVECTIVE RAIN ( IS THE SHAPE OF THE GAMMA DSD).