Swan Range

Localized spring weather may keep you on your toes today.  Steer around isolated pockets of wind-drifted snow along ridgelines. Keep in mind that low danger still has danger in the title.

Last Sunday (April 2nd) was an active period of avalanche activity. Most of the reported slides came from the Flathead Range and southern Glacier National Park. What was notable about this activity was that experienced riders were surprised by remotely-triggered avalanches, avalanches breaking wider than expected, and some avalanches wrapping around to different slope aspects. These are characteristics of a Persistent Slab problem, rather than a Storm Slab. Observers identified that these slides were primarily on shaded aspects (northwest, north, and east) and that the 8 to 12 inches of new snow failed on a layer of faceted grains, at the interface of new and old snow. 

We removed the Wind Slab problem in the Swan and the Whitefish Range, given that these areas received less snow and winds have been generally light over the past 48 hours. Pockets of isolated wind slabs may still lurk along the side of ridgelines. Pay attention to dune-shaped pillows of snow and steer clear of these drifts.

Since then, the snowpack is trending towards increasingly stable conditions, with some uncertainty about how long this persistent weak layer will be reactive. Given the current unsettled weather pattern of a mix of sun, clouds, convective snow showers, and below-normal ambient air temperatures, today’s avalanche hazards run a wide range of possibilities. As you travel, you may encounter localized weather that is isolated to a relatively small area.  If the sun does come out for an extended period, wet instabilities are possible. On the other end of the spectrum, light snow accumulations from convective precipitation may add unconsolidated snow to our weekend's accumulations. Additionally, if moderate southwest winds develop, new snow may build drifts of dense snow. These wind slabs may be small, but still capable of knocking the unsuspecting rider off their feet. 

With this in mind, we hope that in the final week of our daily forecasts for the 2022-2023 winter season, our community members have the tools and information needed to adjust travel plans based on changing conditions. Have feedback for us? Let us know how we can serve you better with our annual survey. Special thanks to Friends of FAC for creating this survey: link here.

FAC will issue daily forecasts through Easter Sunday, April 9. Following this, we will give snowpack updates several times a week through April if conditions dictate.