The Southwest has already experienced a modest increase in some measures of heavy precipitation, thought not to the extent of other regions. For example, storms in the 99th-percentile category increased by 10% from 1958 to 2016 across the region. Intense rainfall is expected to continue to occur more frequently in the future, even though overall precipitation is expected to decline. For example, large rain events that historically had an expected return of 5 years are expected to occur twice as often by the end of the century, under a high emission scenario (RCP 8.5). More of the region's rainfall is projected to be delivered in large storms, as opposed to more moderate rainfall events. In the Southwest, 20-year return storms are projected to deliver 13 to 20% more rainfall by the end of the century.