The relationship between whumpf observations and avalanche activity in Colorado, USA

By: , and 

Links

Abstract

Triggering whumpfs is a primary indicator of unstable snowpack conditions. Although backcountry travelers and avalanche forecasters rely on whumpfs as a warning sign of potential avalanches, there is little formal research to confirm this relationship. This study investigated the temporal correlation between whumpfs and avalanche activity in data from Colorado's Front Range and southern San Juan Mountains between the winters of 2010/11 and 2022/23. To assess changing conditions over a variety of seasons, we compared the timing of whumpfs and avalanches to the total snow depth at a representative site. We used a 13-inch (33 cm) rolling-window average snow depth versus the median for observed whumpfs, and small avalanches (D1 to D1.5), and large to very large avalanches (D2 and greater). Our results support informal observations that whumpfs are important indicators of avalanche activity, especially at shallower snow depths. Later in the season, when snow depths are deeper and basal weak layers become more difficult to trigger, whumpfs become less common even during periods of increasing avalanche activity. Some of our results may be due to the thin, weak, and wind-affected snow in the Colorado Front Range, where whumpfing typically occurs due to collapsing basal depth hoar. Our findings are important for backcountry travelers assessing stability and for backcountry avalanche forecasters communicating conditions to the public. Our data show that although whumpfs generally indicate unstable conditions and correlate with avalanche activity, the largest avalanches of the winter may not always be preceded by whumpfing.

Study Area

Publication type Conference Paper
Publication Subtype Conference Paper
Title The relationship between whumpf observations and avalanche activity in Colorado, USA
Year Published 2023
Language English
Publisher International Snow Science Workshop
Contributing office(s) Northern Rocky Mountain Science Center
Description 7 p.
Larger Work Type Book
Larger Work Subtype Conference publication
Larger Work Title Proceedings, International Snow Science Workshop 2023
First page 1032
Last page 1038
Conference Title International Snow Science Workshop 2023
Conference Location Bend, OR
Conference Date October 8-13, 2023
Country United States
State Colorado
Other Geospatial Front Range Mountains, San Juan Mountains
Google Analytic Metrics Metrics page
Additional publication details