Condition Cumulative Probability SPI Extremely drought 0.0014 -3.0 Very severe drought 0.0062 -2.5 Severe drought 0.0228 -2.0 Moderately drought 0.0668 -1.5 Mildly drought 0.1587 -1.0 Nearly normal 0.3085 -0.5 Normal 0.50 0 Nearly normal 0.6915 0.5 Mildly wet 0.8413 1.0 Moderately wet 0.9332 1.5 Severe wet 0.9772 2.0 Very severe wet 0.9938 2.5 Extremely wet 0.9986 3.0

Table 1: Classification of drought using SPI values and probabilities associated with each event [18] Formed and fitted to the time series distribution.