Taken together, the observed record from California suggests that (i)
precipitation deficits are more likely to yield 1 - SD PMDI droughts if they
occur when conditions are warm and (ii) the occurrence of 1 - SD PMDI droughts, the probability of
precipitation deficits producing 1 - SD PMDI droughts, and the probability of
precipitation deficits co-occurring with warm conditions have all been greater in the past two decades than in the preceding century.