Overview
Winter 2025–2026 (December 2025 – February 2026) was officially the warmest winter on record across the western United States by a wide margin, according to Dr. Daniel Swain, a climate scientist who hosts the Weather West channel . He described the margin of record-breaking warmth as "ridiculous," noting that virtually no corner of the West escaped highly anomalous temperatures .
Extent of Record Warmth
The geographic scope of the record heat was extraordinary. The zone of record-warm temperatures stretched from the central plains of Nebraska and Kansas, across the Front Range of the Rockies, through the Colorado River headwaters, the Great Basin, the Northern Rockies (including the Bitterroots, Tetons, and western Montana), and into most of California — a swath that would take approximately 20 hours to drive across at freeway speeds .
The only partial exception was California's Central Valley, where persistent tule fog suppressed daytime highs — yet even there, nighttime temperatures were warmer than average, keeping the season well above the recent climate normal . Swain used provisional data from the PRISM Climate Group, mapped by Alaska-based climatologist Brian Brett Schneider, to illustrate that the crimson-shaded (all-time record warmth) area covered the majority of the West across 131 years of instrumental records .
Temperature Anomalies
The actual temperature departures were staggering. Across the interior West — including the northern and central Rockies and the Great Basin — seasonal temperatures were more than 10°F above the 1991–2020 climate normal baseline . Critically, that baseline already incorporates 2–3°F of prior climate warming, meaning actual departures from a mid-20th-century baseline were even larger .
Precipitation Picture
Unlike temperature, precipitation varied strongly by region:
-
California: Most of the state received near-average precipitation; northeastern California and the central coast saw 125–150% of average rainfall, making it a reasonable water year for that state
-
Colorado River Basin / Utah / Arizona: Experienced both record warmth and severely below-average precipitation — some parts of Utah received under 50% of average
-
Northern Rockies: Very wet, but much precipitation fell as rain rather than snow due to record warmth
-
Pacific Northwest: Western Washington had a decent water year; western Oregon was somewhat below average
Snowpack Crisis
Snowpack across the West is in "truly dire straits" in Swain's words . Key findings as of March 1, 2026:
-
The upper Colorado River Basin snowpack is tied with or below its all-time record low for this date in a ~50-year observational record
-
Hundreds of monitoring sites across the West show red (all-time record low) or orange (second-lowest ever) snowpack readings
-
The Pacific Northwest snowpack is at roughly the 5th percentile — extremely low
-
Good news is limited to a few pockets: high elevations of the southern Sierra Nevada (up to 150% of average above ~9,000 ft) and parts of the northern Rockies at the highest elevations
The elevational pattern is telling — warmth has obliterated snowpack at low and mid elevations, while only the highest, coldest elevations retain meaningful snow .
Water Supply Implications
The warm winter effectively advanced the hydrological calendar by one season. Precipitation that would normally enter watersheds as snowmelt in spring and summer entered as rain or early melt during winter, producing spring-like soil moisture levels at the end of February . While current soil moisture is temporarily above average in some basins, this water is already gone and will not be available during the critical summer dry season .
The hardest-hit water users include:
-
Cities dependent on the Colorado River: Phoenix, Las Vegas, and communities across the Southwest
-
Agriculture throughout the southern Rockies and northern Mexico
-
Tribal nations in the Colorado Basin
-
Southern California, which relies heavily on Colorado River allocations
Wildfire Risk
While the livestream did not reach a deep dive into wildfire projections, Swain emphasized that the combination of record warmth, depleted snowpack, and early soil moisture drawdown significantly elevates wildfire risk heading into spring and summer 2026 — particularly across the Colorado Plateau and the Great Basin .
Media Coverage Critique
Swain offered a pointed critique of news coverage asymmetry: the eastern U.S. experienced a top-25 coldest winter (in about 130 years of records), which generated extensive dramatic headlines, while the singular all-time record warmth across 10–14 western states received comparatively little attention . He attributed this partly to shrinking climate journalism capacity in newsrooms, but warned that the normalization of such extreme warmth is itself a serious problem .
Short-Term Outlook
The outlook at the time of the broadcast (March 2, 2026) was "not very promising" for snowpack recovery . Swain expected snowpack in the upper Colorado and Pacific Northwest to continue declining relative to averages, with both earlier and lower peak snowpack than normal across virtually the entire West .
No comments:
Post a Comment