mgrib(grib_id = "z500", grib_input_file_name = "z500.grb") mcont(contour_line_colour = "evergreen", contour_label_colour = "navy", contour_label_height = "0.5", contour_highlight_thickness = 2, contour_line_thickness = 2, contour_label = "on", contour_highlight_colour = "kellygreen", legend = "off", contour_line_style = "dash")