A UNIFIED PARAMETERIZATION OF DRY AND MOIST CONVECTIONLOW-LEVEL CLOUDS CONTRIBUTE SIGNIFICANTLY TO EARTHS RADIATIVE BALANCE AND TO THE VERTICAL TRANSPORT OF HEAT AND MOISTURE. THE REPRESENTATION OF LOW-LEVEL CLOUDS AND CONVECTION IN CLIMATE MODELS IS TIED TO AN ACCURATE REPRESENTATION OF THE MIXED LAYER AND MOIST CONVECTION. HOWEVER DEFICIENCIES IN CURRENT MODEL REPRESENTATION OF LOW-LEVEL CLOUDS AND CONVECTION PERSIST; AMONG THE OUTSTANDING CHALLENGES ARE: 1) THE REPRESENTATION OF SUBGRID PROCESSES AND HETEROGENEITIES IN THE STATE PROPERTIES AND CLOUD COVER; 2) THE UNIFICATIONOF MOIST CONVECTIVE PROCESSES WITHIN A SINGLE FRAMEWORK COMPREHENSIVELY VALIDATED AGAINST OBSERVATIONS; AND 3) THE TRANSITION BETWEEN DIFFERENT TYPES OF CONVECTION (STRATOCUMULUS TO SHALLOW CONVECTION SHALLOW TO DEEP CONVECTION DRY TO SHALLOW CONVECTION) DESPITESOME RECENT ADVANCES.IN PRIOR WORK WE DEVELOPED A SEMI-ANALYTIC BULK MODEL OF THE COUPLED MIXED-LAYER AND MOIST CONVECTION DENOTED THE PROBABILISTIC BULK CONVECTION MODEL (PBCM) WHICH IS BASED ON A PROBABILITY DISTRIBUTION FUNCTION (PDF) OF PLUMES. THESE ADVANCES APPEAR PROMISING TO ADDRESS THE DEFICIENCIES NOTED ABOVE. THE PROPOSED WORK ULTIMATELY AIMS TO INCORPORATE PBCM INTO THE NASA GODDARD INSTITUTE FOR SPACE STUDIES (GISS) GCM MODEL E. TO ACHIEVE THIS THE PROPOSED WORK WILL FURTHER TEST AND VALIDATE THE EXTENSION OFPBCM TO ACCOUNT FOR STRATOCUMULUS. PBCM WILL NEXT BE EMBEDDED INTO THE NASA GISS SINGLE COLUMN MODEL (SCM) AND VALIDATED ACROSS A WIDE ARRAY OF TEST CASES AND DATA SETS I.E. BOMEX ATEX ARM CGILS: CFMIP-GCSS INTERCOMPARISON OF LARGE-EDDY AND SINGLE-COLUMN MODELS. CONCURRENT WITH THESE ACTIVITIES WE WILL EVALUATE A NEW FORMULATION OF ENTRAINMENT USING A STOCHASTIC ENTRAINING PLUME MODEL AND THE EXTENSION OF THE MODEL TO REPRESENT STRATOCUMULI WITH THE INCLUSION OF A PDF OF DOWNDRAFTS. LASTLY WE WILL USE THE COUPLED PBCM-SCM FRAMEWORK TO DEVELOP A CONVECTION PARAMETERIZATION THAT CAN BE INCORPORATED INTO NASA GISSMODEL E. WE ANTICIPATE THAT THE NEW COUPLING BETWEEN THE MIXED LAYER AND MOIST CONVECTION AND THE PDF APPROACH WILL SUBSTANTIALLY IMPROVE THE REPRESENTATION OF MOIST CONVECTION IN THE MODEL BY FOR EXAMPLE ENHANCING THE MODEL S ABILITY TO SIMULATE TRANSITIONS BETWEEN THE DIFFERENT CONVECTION REGIMES.