Avalanche forecast

Swan Range

Flathead Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

You could trigger an avalanche in mushy snow as the day heats up. Warm temperatures and sunshine may initiate slides at upper elevations. Choose lower-angle slopes or stay ahead of the sun for a safer experience. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Today is the final day of an extended run of warm and sunny conditions responsible for the Wet Loose problem. Fortunately, modest daytime highs and well below-freezing readings overnight have limited the extent of avalanche activity. However, temperatures have slowly climbed over the past few days resulting in the surface crust on solar aspects breaking down earlier, with warming beginning to affect the snow surface on the northern side of the compass. 

     The crust thins with elevation and is found on sunny slopes up to 7000 feet or higher. As the crust deteriorates through the day, the danger will rise. With today's warming temperatures, recycled powder on shady slopes may be susceptible to developing wet snow instabilities.

    The natural Wet Loose avalanche activity on sunny slopes below 7000 feet is diminishing, but today's warming may initiate slides above this elevation. Triggering a slide in mushy surface snow remains likely as the day heats up. A crust that cannot support you or your machine indicates instability. Rollerballs and pinwheels are precursors to a wet slide. 

    Stay ahead of the sun today, or select lower-angle slopes to enjoy the corn-like conditions. Choose a route that does not expose you to steep overhead westerly aspects on your exit. Limit time above terrain traps where even a small slide can pile up deep. Northerly aspects should remain safer and hold higher-quality snow.

     

    (1/8/2023)

    Small rollerballs due to the warming of the surface snow.

Avalanche Discussion

Spring-like weather continues today before cooler and moist weather returns Monday and into at least the middle of the week.  Unfortunately, we find ourselves in a split flow, with most of the moisture staying south of our area and continuing to build upon the near-record snowpack in the Sierra Nevada Mountains of California. 

This is the fourth and final day of our current wet snow instabilities. Daytime and overnight temperatures have climbed slightly each of the past four days. We have bumped the danger rating to MODERATE at upper elevations to account for this warming. 

Yesterday, a group of riders was surprised by a hard slab avalanche that occurred during their ascent of Red Crow Mountain (7800') near Firebrand Pass just east of Marias Pass. The crown was 2-3 feet thick and 500 feet wide, with the debris traveling 800 feet. Interestingly, mountain goats may have triggered this slide as the party saw goats on the summit and found their prints on the summit ridge, and saw the tracks cross the bed surface.  These folks felt fortunate for their timing and had considered that slope generally benign and discussed using some of it for their approach. We sincerely thank this group for sharing this information in the interest of public safety.

The BNSF avalanche safety team was in John F. Stevens Canyon, where they did not notice any instabilities (Observation) An experienced rider visited the Middle Fork and found several cm of new snow on top of the crust on more northerly/sheltered aspects. Any sort of direct sun resulted in near-instant glopping. They observed a couple of glide cracks opening on solar aspects in Glacier and a handful of point releases on Mt Grant (Observation).

I toured the Autumn Creek trail just west of Marias Pass to document avalanche activity that had affected the trail. We noted three large crowns from the late-February avalanche cycle with two debris piles traveling long distances. I was in this neighborhood Friday and was surprised by the loose, dry snow on shaded low and mid-elevation slopes. Unfortunately, some of this snow had warmed and was sticky and glopping to skins by mid-day yesterday (Observation).

FOFAC Event: March 30th, 2023– Whether you're 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.

Regions covered