Item: TEMPERATURE INVERSIONS AND AVALANCHE CHARACTER IN THE CENTRAL WASATCH: A STATION BASED ANALYSIS
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Title: TEMPERATURE INVERSIONS AND AVALANCHE CHARACTER IN THE CENTRAL WASATCH: A STATION BASED ANALYSIS
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- Haley Brenkmann [ Salt Lake Community College, Salt Lake City, Utah ]
Date: 2026-09-28
Abstract: Atmospheric temperature inversions form under clear, calm, high-pressure conditions and are shaped by both synoptic weather and local topography. We tested whether inversion strength relates to snowpack and avalanche conditions using 3,777 avalanche observations from Little and Big Cottonwood Canyons (1996–2025), alongside mountain temperature records from the Brighton SNOTEL station (8,790 ft; 2,679 m) and Snowbird SNOTEL station (9,170 ft; 2,795 m), and lower-elevation temperature observations from Hawthorne (4,285 ft; 1,306 m), Rose Park (4,249 ft; 1,295 m), and Salt Lake City International Airport (4,227 ft; 1,288 m). Together, these stations span approximately 4,900 ft (1,500 m) of elevation and allowed us to compare valley and mountain temperatures and characterize the strength and occurrence of temperature inversions across the Salt Lake Valley–Central Wasatch elevation gradient. Strong-inversion days had higher storm water equivalent, narrower avalanche crowns, and a different mix of avalanche problem types (p < 0.001 for all). PM2.5 concentrations were nearly twice as high on strong-inversion days (16.8 vs. 8.8 μg/m³, p ≈ 2×10⁻⁴⁵), confirming the measure as a valid valley-scale signal. Strong inversions did not increase avalanche frequency: daily counts were actually lower (3.30 vs. 4.46, p = 0.0027). Persistent-weak layer avalanches were not associated with stronger inversions on the day they occurred. However, the strongest inversion anomalies occurred approximately 2–3 weeks before these avalanches. This timing is consistent with inversions creating cold, stable conditions favorable for surface-hoar formation, followed by burial of that weak layer during subsequent snowfall and eventual avalanche release. Overall, these results suggest that temperature inversions are more closely associated with snowpack development and avalanche characteristics than with an immediate increase in avalanche activity. The delayed relationship between strong inversions and persistent-weak-layer avalanches is particularly important, indicating that inversion periods may help identify atmospheric conditions favorable for weak-layer development weeks before avalanche release. Rather than serving as a direct predictor of avalanche frequency, inversion strength may therefore provide useful context for understanding how periods of cold, stable weather influence the evolution of persistent avalanche problems in the Central Wasatch.
Object ID: ISSW2026_P2.1.pdf
DOI: https://doi.org/10.15788/1790098896
Language of Article: English
Presenter(s): Haley Brenkmann
Keywords: temperature inversion, avalanche, snowpack, Wasatch, SNOTEL, cold-air pooling
Page Number(s): 15 - 22
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