I have looked at several posts here and on other sites but have not found a solution to the problem I am having with this python script. In this script I use 2 nested 'for' loops to extract a series of variables by month (month = 0 - 11) from 5 netcdf files and then mosaic together each extracted variable. The script runs but after processing about 3 variables, I get the following error statement:

ExecuteError: ERROR 999999: Error executing function. Failed to copy raster dataset Failed to execute (MosaicToNewRaster).

In this script I use 2 nested 'for' loops to extract a series of variables by month (month = 0 - 11) from 5 netcdf files and then mosaic together each extracted variable. The script runs but after processing about 3 variables, I get the following error statement:

ExecuteError: ERROR 999999: Error executing function. Failed to copy raster dataset Failed to execute (MosaicToNewRaster).

Import arcpy module

import arcpy import os

Set Geoprocessing environments

arcpy.env.scratchWorkspace = "C:\WORKSPACE\Process_4" SCRATCH = arcpy.env.scratchWorkspace

Script arguments

ENA = arcpy.GetParameterAsText(0) if ENA == '#' or not ENA: ENA = "F:\GISdata\Projects\USGSClimateChange\climateproj\srf_ena_eh5_2030-2034_avg_trim_v4.nc"

NRM = arcpy.GetParameterAsText(1) if NRM == '#' or not NRM: NRM = "F:\GISdata\Projects\USGSClimateChange\climateproj\srf_nrm_eh5_2030-2034_avg_trim_v4.nc"

PNW = arcpy.GetParameterAsText(2) if PNW == '#' or not PNW: PNW = "F:\GISdata\Projects\USGSClimateChange\climateproj\srf_pnw_eh5_2030-2034_avg_trim_v4.nc"

PSW = arcpy.GetParameterAsText(3) if PSW == '#' or not PSW: PSW = "F:\GISdata\Projects\USGSClimateChange\climateproj\srf_psw_eh5_2030-2034_avg_trim_v4.nc"

SRM = arcpy.GetParameterAsText(4) if SRM == '#' or not SRM: SRM = "F:\GISdata\Projects\USGSClimateChange\climateproj\srf_srm_eh5_2030-2034_avg_trim_v4.nc"

Output_Location = arcpy.GetParameterAsText(5) if Output_Location == '#' or not Output_Location: Output_Location = "F:\GISdata\Projects\USGSClimateChange\climateproj\summary\"

#Variable list for variable in ['SNOW', 'SMR', 'SWI', 'T0', 'T33', 'TA']:

SCRATCH = arcpy.env.scratchWorkspace I attempted to place SCRATCH within the loop thinking that it would be recreated. Nope.

#Month Iteration
for month in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]:
    ENA_Layer = SCRATCH +"\\ENA"+variable+str(month)
    NRM_Layer = SCRATCH +"\\NRM"+variable+str(month)
    PNW_Layer = SCRATCH +"\\PNW"+variable+str(month)
    PSW_Layer = SCRATCH +"\\PSW"+variable+str(month)
    SRM_Layer = SCRATCH +"\\SRM"+variable+str(month)

    # Process: Make NetCDF Raster Layer (169)
    arcpy.MakeNetCDFRasterLayer_md(ENA, variable, "x", "y", ENA_Layer, "", "time "+ str(month), "BY_INDEX")

    # Process: Make NetCDF Raster Layer (157)
    arcpy.MakeNetCDFRasterLayer_md(NRM, variable, "x", "y", NRM_Layer, "", "time "+ str(month), "BY_INDEX")

    # Process: Make NetCDF Raster Layer (145)
    arcpy.MakeNetCDFRasterLayer_md(PNW, variable, "x", "y", PNW_Layer, "", "time "+ str(month), "BY_INDEX")

    # Process: Make NetCDF Raster Layer (133)
    arcpy.MakeNetCDFRasterLayer_md(PSW, variable, "x", "y", PSW_Layer, "", "time "+ str(month), "BY_INDEX") 

    # Process: Make NetCDF Raster Layer (121)
    arcpy.MakeNetCDFRasterLayer_md(SRM, variable, "x", "y", SRM_Layer, "", "time "+ str(month), "BY_INDEX")     
    
    
    # Process: Mosaic To New Raster (25)
    arcpy.MosaicToNewRaster_management("\"" + ENA_Layer +";"+ NRM_Layer +";"+ PNW_Layer +";"+ PSW_Layer +";"+ SRM_Layer +"\"", Output_Location, variable+"_"+str(month)+"2032", "PROJCS['WGS_1984_Lambert_Conformal_Conic',GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Lambert_Conformal_Conic'],PARAMETER['false_easting',0.0],PARAMETER['false_northing',0.0],PARAMETER['central_meridian',-102.3000030517578],PARAMETER['standard_parallel_1',30.0],PARAMETER['standard_parallel_2',60.0],PARAMETER['latitude_of_origin',52.0],UNIT['Kilometer',1000.0]]", "", "1", "1", "MEAN", "FIRST")

arcpy.Delete_management(SCRATCH)

# Import arcpy module
import arcpy
import os

# Set Geoprocessing environments
arcpy.env.scratchWorkspace = "C:\\WORKSPACE\\Process_4"
SCRATCH = arcpy.env.scratchWorkspace


# Script arguments
ENA = arcpy.GetParameterAsText(0)
if ENA == '#' or not ENA:
    ENA = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\srf_ena_eh5_2030-2034_avg_trim_v4.nc" 

NRM = arcpy.GetParameterAsText(1)
if NRM == '#' or not NRM:
    NRM = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\srf_nrm_eh5_2030-2034_avg_trim_v4.nc"

PNW = arcpy.GetParameterAsText(2)
if PNW == '#' or not PNW:
    PNW = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\srf_pnw_eh5_2030-2034_avg_trim_v4.nc" 

PSW = arcpy.GetParameterAsText(3)
if PSW == '#' or not PSW:
    PSW = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\srf_psw_eh5_2030-2034_avg_trim_v4.nc" 

SRM = arcpy.GetParameterAsText(4)
if SRM == '#' or not SRM:
    SRM = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\srf_srm_eh5_2030-2034_avg_trim_v4.nc" 

Output_Location = arcpy.GetParameterAsText(5)
if Output_Location == '#' or not Output_Location:
    Output_Location = "F:\\GISdata\\Projects\\USGSClimateChange\\climateproj\\summary\\" 
    

#Variable list
for variable in ['SNOW', 'SMR', 'SWI', 'T0',  'T33', 'TA']:
    

#    SCRATCH = arcpy.env.scratchWorkspace               I attempted to place SCRATCH within the loop thinking that it would be recreated.  Nope.

    #Month Iteration
    for month in [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]:
        ENA_Layer = SCRATCH +"\\ENA"+variable+str(month)
        NRM_Layer = SCRATCH +"\\NRM"+variable+str(month)
        PNW_Layer = SCRATCH +"\\PNW"+variable+str(month)
        PSW_Layer = SCRATCH +"\\PSW"+variable+str(month)
        SRM_Layer = SCRATCH +"\\SRM"+variable+str(month)

        # Process: Make NetCDF Raster Layer (169)
        arcpy.MakeNetCDFRasterLayer_md(ENA, variable, "x", "y", ENA_Layer, "", "time "+ str(month), "BY_INDEX")

        # Process: Make NetCDF Raster Layer (157)
        arcpy.MakeNetCDFRasterLayer_md(NRM, variable, "x", "y", NRM_Layer, "", "time "+     str(month), "BY_INDEX")

        # Process: Make NetCDF Raster Layer (145)
        arcpy.MakeNetCDFRasterLayer_md(PNW, variable, "x", "y", PNW_Layer, "", "time "+ str(month), "BY_INDEX")

        # Process: Make NetCDF Raster Layer (133)
        arcpy.MakeNetCDFRasterLayer_md(PSW, variable, "x", "y", PSW_Layer, "", "time "+ str(month), "BY_INDEX") 

        # Process: Make NetCDF Raster Layer (121)
        arcpy.MakeNetCDFRasterLayer_md(SRM, variable, "x", "y", SRM_Layer, "", "time "+ str(month), "BY_INDEX")     
        
        
        # Process: Mosaic To New Raster (25)
        arcpy.MosaicToNewRaster_management("\"" + ENA_Layer +";"+ NRM_Layer +";"+ PNW_Layer +";"+ PSW_Layer +";"+ SRM_Layer +"\"", Output_Location, variable+"_"+str(month)+"2032", "PROJCS['WGS_1984_Lambert_Conformal_Conic',GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Lambert_Conformal_Conic'],PARAMETER['false_easting',0.0],PARAMETER['false_northing',0.0],PARAMETER['central_meridian',-102.3000030517578],PARAMETER['standard_parallel_1',30.0],PARAMETER['standard_parallel_2',60.0],PARAMETER['latitude_of_origin',52.0],UNIT['Kilometer',1000.0]]", "", "1", "1", "MEAN", "FIRST")

   arcpy.Delete_management(SCRATCH)