extend = 'max'
bounds = [0, 0.01, 0.1, 0.5, 1.0, 2.0, 4.0, 8.0, 12.0, 20.0, 30.0, 50.0]  #(mm/hr)
cmap = gen_cmap(['w', 'lemonchiffon', 'navajowhite', 'sandybrown',
                 'peru', 'darkseagreen', 'mediumseagreen',
                 'darkcyan', 'dodgerblue', 'slateblue', 'darkslateblue'])
cmap.set_over('mediumvioletred')