Masked Lambert Conformal Projections
mpProjection = "LambertConformal" turns on the correct projection.
gsnMaskLambertConformal = True will turn on the projection masking.
It is also required to set gsnAddCyclic to False whenever you plot a non-global domain.
gsnMaximize enlarges the plot to the point where the fonts are legible. For this type of plot, you will probably want to always have this resource turned on.
gsnMaskLambertConformalOutlineOn turns off a border around the plot
This script uses a procedure called "add_lc_labels" to add the lat/lon labels. You may need to increase or decrease the lat_spacing or lon_spacing arguments if you are not satisfied with the results.