Flathead Range & Glacier NP

Generally safe avalanche conditions exist. If entering avalanche-prone terrain, travel one at a time while keeping a spotter in a safe location. Triggering an avalanche is unlikely, not impossible.

Yesterday (Monday), a quick and weak moving system dropped .2 inches of Snow Water Equivalent at Stahl in the northern Whitefish Range. Remote weather stations in the Swan Range, southern Whitefish Range, and most of the Flathead/southern Glacier National Park show no measurable change in precipitation. Wind speeds increased to 10 to 15 mph out of the south. 

Warming temperatures and clearing skies may produce rollerballs and small Wet Loose slides on steep, sunny aspects. Rocky areas getting clipped by the sun will be the first to slide. Wet Loose avalanches should be small and harmless in size. If cloud cover remains overhead, the snow surface will remain cold and this problem won't develop. 

Buried persistent weak layers exist in the snowpack, but signs of instability are sparse. On March 22nd, an intentionally dropped cornice triggered a Persistent Slab avalanche that failed roughly 2 feet deep (observation). This avalanche occurred in steep, rocky terrain above 7000 feet in the central Whitefish Range. On March 18th, mountain goats triggered a Persistent Slab avalanche on Red Crow Mountain, just outside the advisory area in southern Glacier National Park (observation). Other Persistent Slab avalanches failed on east and north-facing slopes above 6500 feet in early/mid-March. Although we suspect it is very unlikely to trigger a large avalanche today, it is not impossible. If you head into steep terrain above 6500 feet, purchase your travel insurance by riding one at a time, while keeping a partner in a safe location. Give common trigger points a wide berth, such as rocky areas and convex rollovers. 

Sagging cornices and glide cracks will be continuous problems to manage for the remainder of the season. Avoid tumbling down the slope with a cornice by giving the edge of ridgelines a wide berth. Use vegetation and rocks sticking out of the snow as visual clues for safe areas to walk. Move quickly and efficiently if you have to travel below glide cracks or corniced ridgelines. Both problems are more likely to fail during intense heat, but can fail spontaneously with no warning. 

FOFAC Event: March 30th, 2023– Whether chasing tan lines, big lines, or both, you'll learn something valuable from FAC Lead Forecaster Mark Dundas about spring avalanche problems, how they differ from winter problems, and how to manage them. We will also discuss current conditions and concerns (or lack thereof!) with our spring snowpack. Enjoy a cold brew from Bias Brewing and a scoop from Sweet Peaks Ice Cream. The event is free and open to everyone. Begins at 6 pm.