Brown et al. (2026) Historical evolution of snowpack capacity to buffer rain-on-snow runoff in a large Columbia River headwaters basin

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-09-10
• Authors: Joel Brown, J. T. Harper
• DOI: 10.5194/hess-30-5735-2026

Research Groups

• Department of Geosciences, University of Montana
• Aesir Consulting LLC

Short Summary

This study investigates the historical evolution of snowpack capacity to buffer rain-on-snow runoff in a large Columbia River headwaters basin. The results show that the snowpack's ability to buffer runoff has declined significantly over the past 72 years, with the largest declines occurring during the spring period.

Objective

• Investigate long-term changes in snowpack properties and their impact on rain-on-snow (ROS) events

Study Configuration

• Spatial Scale: A large Columbia River headwaters basin in NW Montana, USA
• Temporal Scale: 72-year model simulation from 1951 to 2022

Methodology and Data

• Models used: Alpine3D, a distributed snowpack model that tracks the layer-by-layer development of heat, mass, and structural framework of the snowpack throughout the snow season.
• Data sources: ERA5-Land reanalysis products for meteorological forcing.

Main Results

• The snowpack's ability to buffer runoff has declined significantly over the past 72 years, with the largest declines occurring during the spring period.
• The number of days with ripe snowpack and elevated ROS risk increased substantially.
• Late-season LWbc decreased by 42%–80% relative to the early season.

Contributions

• This study provides critical context for interpreting recent and future hydrologic risks in mountainous regions.
• The findings highlight the importance of considering long-term changes in snowpack properties when assessing ROS risk.

Funding

• Not specified

Citation

@article{Brown2026Historical,
  author = {Brown, Joel and Harper, J. T.},
  title = {Historical evolution of snowpack capacity to buffer rain-on-snow runoff in a large Columbia River headwaters basin},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-5735-2026},
  url = {https://doi.org/10.5194/hess-30-5735-2026}
}