Identifying Coherence Across End-of-Century Montane Snow Projections in the Western United States Journal Article uri icon



  • Montane snowpack is a vital source of water supply in the Western United; States. However, the future of snow in these regions in a changing; climate is uncertain. Here, we use a large-ensemble approach to evaluate; the consistency across 124 statistically downscaled snow water; equivilent (SWE) projections between end-of-century (2076 – 2095) and; early 21st century (2106 – 2035) periods. Comparisons were performed on; dates corresponding with the end of winter (15 April) and spring; snowmelt (15 May) in five western US montane domains. By benchmarking; SWE climate change signals using the disparity between snow projections,; we identified relationships between SWE projections that were repeatable; across each domain, but shifted in elevation. In low to mid-elevations,; 15 April average projected decreases to SWE of 48% or larger were; greater than the disparity between models. Despite this, a significant; portion of 15 April SWE volume (39 – 93%) existed in higher elevation; regions where the disparities between snow projections exceeded the; projected changes to SWE. Results also found that 15 April and 15 May; projections were strongly correlated (r 0.82), suggesting that; improvements to the spread and certainty of 15 April SWE projections; would translate to improvements in later dates. The results of this; study show that large-ensemble approaches can be used to measure; coherence between snow projections and identify both 1) the; highest-confidence changes to future snow water resources, and 2) the; locations and periods where and when improvements to snow projections; would most benefit future snow projections.

publication date

  • August 14, 2023

has restriction

  • green

Date in CU Experts

  • August 16, 2023 6:20 AM

Full Author List

  • Pflug J; Kumar S; Livneh B; Gutmann ED; Gangrade S; Kao S-C

author count

  • 6

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