Shelton et al. (2026) Impacts of subtropical pacific variability on snow precipitation fraction (SPF) in the upper Colorado river basin

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Environmental Research Letters
• Year: 2026
• Date: 2026-03-30
• Authors: Sherly Shelton, Snehadeep Ballav, Lydia R. Conger, Jake Utley, Hadia Akbar, Pamela Claure Gutierrez, Gage Farley, Wei Zhang
• DOI: 10.1088/1748-9326/ae58bb

Research Groups

Not explicitly stated in the abstract.

Short Summary

This study investigates the spatiotemporal variability of the snowfall-to-total-precipitation fraction (SPF) in the Upper Colorado River Basin (UCRB) during the cold season (1980–2022), revealing a distinct north-south gradient and a strong connection between SPF variability and large-scale ocean-atmosphere interactions, particularly the Pacific Meridional Mode (PMM).

Objective

• To investigate the spatiotemporal variability of the snowfall-to-total-precipitation fraction (SPF) in the Upper Colorado River Basin (UCRB) during the cold season (November–March) for the 1980–2022 period.

Study Configuration

• Spatial Scale: Upper Colorado River Basin (UCRB)
• Temporal Scale: Cold season (November–March) from 1980 to 2022 (43 years).

Methodology and Data

• Models used: Empirical Orthogonal Function (EOF) analysis.
• Data sources: Not explicitly stated in the abstract (e.g., specific precipitation datasets, reanalysis products).

Main Results

• A distinct north–south gradient in SPF is observed across the UCRB.
• Snowfall remains the dominant component of total precipitation, except in the southern and central regions of the UCRB.
• The leading mode of SPF variability, identified through EOF analysis, explains 50.3% of the total variance.
• This leading mode is strongly linked to the Pacific Meridional Mode (PMM).
• A statistically significant negative correlation exists between the PMM index and SPF.
• Positive PMM phases are associated with warmer surface air temperatures and circulation anomalies (e.g., 500-hPa geopotential height patterns) that suppress snow formation, leading to lower SPF values.

Contributions

• Highlights the strong influence of large-scale ocean–atmosphere variability, specifically the Pacific Meridional Mode (PMM), on precipitation phase partitioning in the Upper Colorado River Basin.
• Provides crucial insights for regional water resource management and climate adaptation planning in the UCRB.

Funding

Not mentioned in the abstract.

Citation

@article{Shelton2026Impacts,
  author = {Shelton, Sherly and Ballav, Snehadeep and Conger, Lydia R. and Utley, Jake and Akbar, Hadia and Gutierrez, Pamela Claure and Farley, Gage and Zhang, Wei},
  title = {Impacts of subtropical pacific variability on snow precipitation fraction (SPF) in the upper Colorado river basin},
  journal = {Environmental Research Letters},
  year = {2026},
  doi = {10.1088/1748-9326/ae58bb},
  url = {https://doi.org/10.1088/1748-9326/ae58bb}
}