Eastern US Covered in Winter Storms, Western US Lacks Snow

The ski season has officially begun, yet while heavy snow blankets the eastern United States, the western regions are experiencing a sluggish start. As of December 1, 2025, snow levels in much of the West were well below average. Denver recorded its first measurable snowfall on November 29, over a month later than usual, marking one of the citys latest initial snowfalls in recorded history. However, experts caution that a delayed start does not automatically signal a poor season ahead.

Adrienne Marshall, a Colorado-based hydrologist studying snow patterns in the West, notes that forecasters are closely monitoring several factors, including the impact of rising temperatures on future snowfall.

What Forecasters Are Watching

The National Weather Service Climate Prediction Center projects that from January to March 2026, winter conditions will generally follow a La Nia pattern: cooler and wetter in the northern regions and warmer and drier in the south. Despite this, early-season snowfall is highly unpredictable, and a late first snow does not necessarily indicate a below-average season.

La Nia refers to cooler-than-average Pacific Ocean temperatures near the equator west of South America. While this pattern influences U.S. weather, it is not the sole determinant. La Nia tends to bring wetter conditions to the Pacific Northwest and slightly drier weather to the Southwest, but outcomes vary.

For snow accumulation, La Nia can suggest heavier snowfall in the Northwest and lighter snowfall in the Southwest, yet randomness in storm activity plays a major role. Snow-water equivalent measurements show most western regions were below normal by November 30, 2025, although parts of the Southwest had above-average early-season totals.

Climate Change and Western Snowfall

Long-term records show that snowfall in the West has generally declined since the 1920s, accompanied by more midwinter melting. Snow levels are influenced by both temperature and precipitation, with rising temperatures reducing snowpack, especially in the Southwest. Research attributes much of the recent decline in spring snowpack directly to human-induced climate change.

Future climate projections indicate that warmer conditions will likely lead to less snow, and higher greenhouse gas emissions could worsen the trend. Even with moderate emissions, the frequency of low-snow years is expected to increase.

Implications for Water Supplies

Snowpack serves as a critical water reservoir for western states. California, for instance, depends on snow for roughly a third of its annual water supply. Warmer temperatures cause earlier snowmelt, sometimes accelerated by rain-on-snow events, increasing flood risks. Early snowmelt complicates reservoir management, as water managers must balance flood prevention with long-term water storage.

Large reservoirs in the Colorado River basin, such as Lake Powell and Lake Mead, show long-term declines, reflecting the growing mismatch between water supply and demand.

Other Effects of Snow Variability

Lower snow levels result in earlier soil drying, extending the fire season and placing stress on forests. Wildlife dependent on snow, like the endangered wolverine, is also affected. Overall, climate projections suggest fewer extreme snow years and more frequent low-snow seasons unless emissions are significantly reduced.

While projections are scenario-based and not definitive predictions, they highlight how human choices can influence future snowfall and broader climate conditions.

Author: Maya Henderson