Colorbar

D0: Abnormally Dry (-0.50 to -0.79); D1: Moderate Drought (-0.80 to -1.29); D2: Severe Drought (-1.30 to -1.59); D3: Extreme Drought (-1.60 to -1.99); D4: Exceptional Drought (-2.0 or less)

W0: Abnormally Wet (0.50 to 0.79); W1: Moderate Wetness (0.80 to 1.29); W2: Severe Wetness (1.30 to 1.59); W3: Extreme Wetness (1.60 to 1.99); W4: Exceptional Wetness (2.0 or more)

http://drought.eng.uci.edu/