I want to use NCL to calculate the average annual precipitation from a output of RegCM model (nc file) that has a daily output. I have written the following script on NCL. But the final map is different from the map drawn in Ward. please guide me.

; These files are loaded by default in NCL V6.2.0 and newer

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"

load "$NCARG_ROOT/lib/ncarg/nclscripts/contrib/cd_string.ncl"

begin

;----------------------------------------------------------------------

; Read data

;----------------------------------------------------------------------

filename = "ATM.1974010100.nc"

a = addfile(filename,"r")

pre1 = a->pr(:,:,:)

; u1 = a->TPRATE_P11_L1_GLL0_acc(50,68,:,:)

; u2 = a->TPRATE_P11_L1_GLL0_acc(50,44,:,:)

;printVarSummary(u)

wks = gsn_open_wks("pdf","regcm") ; send graphics to PNG file

;----------------------------------------------------------------------

; Set some map resources

;----------------------------------------------------------------------

res = True

res@gsnMaximize = False ; maximize plot in frame

res@gsnDraw = False

res@gsnFrame = False

res@cnFillOn = True ; turn on contour fill

res@cnFillPalette = "BlGrYeOrReVi200"

;res@cnFillPalette = "wgne15"

res@cnLinesOn = False ; turn off contour lines

res@cnLineLabelsOn = False ; turn off contour labels

res@lbLabelBarOn = True ; turn on labelbar

;*************************

;bar

res@cnLevelSpacingF = 50 ; set finer contour spacing

;res@cnLevelSelectionMode = "ExplicitLevels" ; use explicit levels

; res@lbOrientation = "Vertical" ; vertical labelbar

;===================

res@mpOutlineBoundarySets = "National"

res@pmTickMarkDisplayMode = "conditional"

res@mpNationalLineThicknessF = 1.0 ; interior boundaries

res@mpGeophysicalLineThicknessF = 1.0 ; lines separating land/ocean

;=================

res@gsnAddCyclic = False

res@trYReverse = True

res@cnConstFEnableFill = False

res@cnConstFLabelOn = True

;=================

res@mpLimitMode = "LatLon"

res@mpMinLatF = 0

res@mpMaxLatF = 60

res@mpMinLonF = 0

res@mpMaxLonF = 120

res@mpFillOn = True

res@mpOutlineOn = True

res@tiMainString = "16 to 27 october 2017" ; set the main title

pre1=dim_avg_n_Wrap(pre1(:,:,:), 0)

plot = gsn_csm_contour_map(wks,pre1,res)

draw(plot)

frame(wks)

end

******Thanks in advance