begin
 fils = systemfunc ("ls *.nc") ; file paths
 a    = addfiles (fils, "r")   
 printVarSummary (a)

 ListSetType (a, "cat")        ; concatenate (=default)
  


;************************************************
; Read the file
;************************************************
 
  ymStrt = 692496                              ; climatology start year/month
  ymLast = 1016808                              ;      "      last  year/month  a  time   = f->time 
  time   = a->time            
  yyyymm = cd_calendar(time, -1)
  ntStrt = ind(yyyymm.eq.ymStrt)                ; start time index
  ntLast = ind(yyyymm.eq.ymLast)                ; last  time index
   prc   = a[:]->precip(ntStrt:ntLast,:,:)               ; read T from all files
   printVarSummary (prc)
  ntim = dimsizes(time)

  months = (/"January", "February", "March", "April" \
            ,"May", "June", "July", "August"         \
            ,"September", "October", "November"      \
            ,"December" /)
;************************************************
; Compute the climatology using a function in contributed.ncl
;************************************************
  tmpClm = clmMonTLL (prc)                      ; monthly climatology
  printVarSummary(tmpClm)
;************************************************
; create colors
;*************************************************
  wks = gsn_open_wks("png","climo_ghcn")             ; send graphics to PNG file

;************************************************
; create panel plots
;*************************************************
  plot   = new (12, graphic)                    ; create graphical array

  res                      = True               ; plot options desired
  res@gsnDraw              = False
  res@gsnFrame             = False
  res@cnFillOn             = True               ; turn on color fill
  res@cnFillPalette        = "amwg256"          ; set color map
  res@cnInfoLabelOn        = False              ; turn off contour info label
  res@cnLinesOn            = False              ; turn off contour lines
  res@cnLineLabelsOn       = False              ; turn off line labels

  res@cnLevelSelectionMode = "ManualLevels"     ; set manual contour levels
  res@cnMinLevelValF       = 0              ; set min contour level
  res@cnMaxLevelValF       = 400              ; set max contour level
  res@cnLevelSpacingF      =   5.0              ; set contour spacing

  res@mpFillOn             = False              ; turn off gray continents
  res@mpCenterLonF         = 0                  ; Centers the plot at 0 
  res@lbLabelBarOn         = False              ; No single label bar
  
 

  

  resP                     = True               ; panel options
  resP@gsnPanelMainString  = " Precipitation: "+(ymStrt/100)+"-"+(ymLast/100)
  resP@gsnMaximize         = True               ; maximize image
  resP@gsnPanelLabelBar    = True               ; Add common label bar 

  do nmo=0,11                                   ; loop over the months
     res@gsnLeftString     = months(nmo)
     plot(nmo) = gsn_csm_contour_map(wks,tmpClm(nmo,:,:), res)  ; create plot
  end do
  
    gsn_panel(wks,plot,(/4,3/),resP)
end