Weather
It’s the start of December, and winter is beginning to take shape across the Western U.S., though it’s been slow in some places. By this time of year, many skiers and snowboarders should have had their first days on the mountain; however, many ski areas haven’t had enough snow to open yet.
The slow start to the season has December snowpack levels well below typical depths for this time of year. Storms have been fewer and weaker than usual, and the cold snaps needed to build and preserve a base have been hit-and-miss. In many basins, snow water equivalent is lagging by a wide margin, leaving mountains bare where they’re usually covered. It’s still early enough for the pattern to shift, but the region is entering December with a noticeable deficit. Meanwhile, the East Coast has seen the opposite, with ski areas opening and skiing conditions proving lovely.
The snowpack builds gradually through the season as layers from each storm settle and compact. When storms are frequent and temperatures stay cold, the snowpack deepens and strengthens. But if the weather turns warm or dry, it can fall behind expectations.
Snowpack is measured in two main ways: total snow depth and snow-water equivalent (SWE). SWE is especially important because it measures how much water is actually stored in the snow, giving a clearer picture of how much runoff might be available in spring. For instance, 10 feet of dense snow can hold as much water as 20 feet of lighter snow.
Let’s take a look at the current SWE across the U.S. to see how this early-season snowpack stacks up against the 30-year median.
Based on the Snow Water Equivalent (SWE) map, here is an analysis of the current snowpack conditions across the Western United States:
Dominance of “Red” (Significant Snow Deficit)
- Widespread Snow Drought: The map is predominantly red and deep orange, indicating that the vast majority of the Western U.S. is experiencing snowpack levels below 50% of the 1991–2020 median.
- Northern & Central Rockies: States that typically rely on early-season storms—Idaho, Montana, Wyoming, and Colorado—are showing critically low numbers. For example, parts of Colorado and Idaho are reporting basin averages as low as 30–40% of normal.
- Pacific Northwest: Washington and Oregon are also mainly in the red. This suggests a high-pressure ridge has likely been blocking the typical storm track that targets the Pacific Northwest in late autumn.
The “Blue” Anomalies
- Arizona & New Mexico Surge: The most striking feature is the bright blue areas in Arizona and parts of New Mexico. This indicates snowpack levels >150% of the median. This pattern is consistent with a “southern track” storm system that bypassed the north and dumped heavy precipitation directly into the Southwest in late November.
- Mammoth/Southern Sierra (California): The localized pocket of blue near Mammoth Lakes in the Eastern Sierra aligns with reports of a specific, powerful storm cycle that hit the region mid-to-late November. While the rest of California (and the wider West) remained dry, this particular area benefited from orographic lift that squeezed out significant snowfall from that southern system.
The winter of 2025–26 is starting with a sharp “dipole” pattern: the typically snowy northern tier is starving for moisture, while the typically drier Southwest is seeing a surplus. This is an inversion of the typical early-season pattern.
