'Miracle' Drought-Busters Becoming Rarer in a Warming Colorado River Basin
The HyperFACETS coauthors.
This coproduction study is the first of HyperFACETS to work with stakeholders in producing research. It introduces a framework for quantifying extreme spring dry-to-wet transition events, termed "miracles," in the Colorado River Basin. Analysis of observations and climate model projections suggests these events may become less frequent and intense in a warming climate.
Understanding the future likelihood of drought-busting springtime precipitation events is crucial for water management in the Colorado River Basin. The projected decline in these "miracle" events has important implications for reservoir operations, flood control planning, and municipal water supply.
In the Colorado River Basin, unexpected surges in late-spring precipitation can rapidly ease severe drought conditions - events colloquially known as "miracles". Through collaboration with regional water managers, this study introduces a framework for characterizing these impactful yet understudied Extreme Spring Dry-to-Wet (ESDW) transitions. Analysis of observations, global climate models, and high-resolution regional simulations indicates that both the frequency and intensity of ESDW events are projected to decline under continued warming. Key factors include an anticipated decrease in precipitation during the crucial months of May and June, likely related to the poleward shift of the North Pacific subtropical high-pressure system. While the Colorado River Basin may trend wetter overall, these findings suggest water managers cannot rely on "miracle" events to alleviate future droughts. The study highlights the need for further research to inform flexible, adaptive management strategies in this critical watershed.