Historical changes in snow conditions for skiing across the contiguous United States based on SNODAS-validated CONUS404 reanalysis

Abstract Climate change poses a significant risk to functional snow availability and the ski industry worldwide. We used the CONUS404 reanalysis dataset, a recently developed tool well-suited assessing for long-term trends in functional snow availability across the contiguous United States. We first validated CONUS404 in terms of snow water equivalent (SWE) and snow depth against the best estimates from National Oceanic and Atmospheric Administration’s (NOAA) SNOw Data Assimilation System (SNODAS) model using the Root Mean Square Error (RMSE) and Pearson Correlation. Results show that CONUS404 underestimates SWE and snow depth relative to SNODAS, especially in the Rocky Mountains, yet maintains reasonable agreement. Time-averaged comparisons yielded an RMSE of 20.35 mm for SWE, 55.29 mm for snow depth, and a Pearson correlation of 0.7 for both variables, indicating that CONUS404 captures temporal variability reasonably well. After confirming the model variables adequately represented real-world conditions, we analyzed historical trends (1980–2022) in SWE, snow depth, and ski-season duration using the Mann-Kendall test and Sen’s slope. Ski viability was assessed by calculating the number of skiable days with a snow depth exceeding 30 cm. A significant downward trend in SWE, snow depth, and number of the skiable days was identified across much of the United States, including popular skiing destinations in the West. In some regions, the decline reached as much as two skiable days per year. In contrast, a small area in the Northeast exhibited an anomalous increase. These findings highlight the regional variability and susceptibility in snow cover and snow season duration across the United States, emphasizing the need for climate action and adaptation strategies to support the ski industry’s future resilience.