Flathead Range & Glacier NP

Enjoy the soft snow and calm weather before Sunday’s arctic intrusion spoils the fun. Minimize your chance of triggering a large avalanche by sticking to slopes less than 35 degrees not connected to steeper terrain above. Recognize that early-season conditions exist on the ground, and safe travel protocols continue to be essential.

Take advantage of calm weather conditions Friday and Saturday before the brutally cold arctic air invades the region Sunday morning. Continue to mitigate the Persistent Slab problem with terrain selection, until we feel confident to remove this problem from the list. Observations are trending toward fewer signs of instability until their not, such as the numerous scary collapses Guy and blase experienced Wednesday. This week's snowfall remains cold, soft, and available for transport. Forecasted wind speeds should stay below the threshold for drifting Friday. If unexpected blustery conditions materialize, you may find new, thin slabs on favored upper-elevation slopes. 

Seasonal precipitation update. You may be surprised to learn that the current Snow Water Equivalent for the Flathead Basin is just 109% median for the 1990-2021 period. Don’t get me wrong, 109% is a number that delights me. However, I’m assuming many area residents believe we are enjoying a banner early season with a well-above-typical snowpack. That rationale seems to make sense because the valley floor has snow, the nordic ski areas are open, the WMR opening weekend included nearly all of their terrain, and low-elevation Forest Service roads have plenty of coverage. On top of that, winter does not officially start for another five days! So what gives? 

Undoubtedly, it has been an uncharacteristically colder fall season, than in years past. Our neighbors in Missoula recorded the second coldest period on record from November 1 to December 10. Instead of alternating doses of rain and snow, we’ve enjoyed nearly all snow this autumn. Snow that fell at low elevations has stuck around and not melted from warm temperatures or washed away by rain.

However, most large storms impacting the western United States have generally gone south of our region and benefitted areas such as the Sierra Nevada, Oregon, the Wasatch, and southern Idaho. In our neighborhood, the southernmost SNOTEL stations reporting a respectable 122% median at Noisy Basin in the Swan Range and 150% at the Blacktail ski area. Unfortunately, the northern mountains have missed the brunt of the precipitation. Flattop in GNP is a paltry 82%, and Stahl Peak in the northern Whitefish Range at 81%. 

Why this matters. In areas harboring a thin snowpack, the buried faceted weak layer is generally more developed and weaker than in areas harboring a deeper pack. This discrepancy is due to a larger temperature gradient on shallow slopes, which helps drive weak snow development. Also, the slab overlying the weak layers is often thinner and weaker, allowing riders and their snowmachines to affect the buried layers more easily, resulting in whumfing collapses and triggered avalanches. 

Training: Now's a great time to hone your companion rescue skills. Transceiver parks are open at Whitefish Mountain Resort, one at the summit and one adjacent to Grey Wolf. Both are accessible to snowmachines. Or focus for a full day at our Ladies Companion Rescue Clinic on Saturday, December 17.   Or check out our Motorized Companion Rescue Clinic on Sunday, December 18. You can get more details about training and education opportunities events on our events calendar.

Observations - Thanks to everyone who's been utilizing our new observation submission page. Try it out and help your community by sharing what you see in the backcountry. The form requires you to fill out the location fields and put a dot on a map. Be as specific or vague as you want. Our new Observation View page highlights signs of instability and allows you to filter by date or zone to pull out reports relevant to your objectives.