THIS AVALANCHE FORECAST EXPIRED ON January 25, 2018 @ 12:00 am
Avalanche Forecast published on January 24, 2018 @ 7:00 am
Issued by Todd Hannan - Flathead National Forest

New snowfall with rising temperatures will create dangerous avalanche conditions as the day progresses. Additional snow and wind expected today will add depth to new storm slabs and stress deeper instabilities. Choose conservative terrain and carefully evaluate the snowpack before committing to a slope.

3. Considerable

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Above 6500 ft.
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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5000-6500 ft.
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

2. Moderate

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3500-5000 ft.
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
  • 1. Low
  • 2. Moderate
  • 3. Considerable
  • 4. High
  • 5. Extreme
Avalanche Problem 1: Storm Slab
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Rising temperatures this morning and increasingly heavy, wet snow will help to consolidate overnight snow into a fresh storm slab.  These slabs will thicken and become more reactive with new snow and wind expected today. Additionally, recent moderate to strong winds created slabs along leeward ridgelines that will need time to adjust to the new load. These slabs will be thicker and likely more reactive as you approach the Continental Divide. Keep in mind that even a small storm/wind slab avalanche adds rapid stress to the snowpack and can trigger deeper instabilities. You can identify storm instabilities by looking for cracking in the surface snow under your feet or machine. 

Avalanche Problem 2: Persistent Slab
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A series of near-surface crusts and associated weak snow exists in many areas, and in isolated areas we observed buried surface hoar (video). New snow today may not be enough to tip the scale into widespread natural avalanches on these layers, but it will certainly add stress to deeper instabilities. Given the variability of our snow pack it is important to dig into the snow and test the reactivity of suspected weak layers. Stick to simple, low angle terrain while the snow pack adjusts to a new load.

Forecast discussion

In the past 24 hours we picked up about 0.5 inches of snow water equivalent. Today is a transition day back into a storm cycle with rising snow levels. There is uncertainty in how high the snow level will rise today. To address this uncertainty it will be important to pay close attention to changing conditions and have a good exit strategy. I don't expect rain to affect the deep, unconsolidated snow in the upper elevation bands, but rain on snow will rapidly deteriorate conditions and the likelihood of loose, wet activity will rise.

As mentioned above, the new snow load will stress buried weak layers in our variable snowpack and it is difficult to determine exactly how much weight these layers can handle. Don't be the straw that broke the camels back, avoid steep complex terrain while the snowpack adjusts and settles.

Yesterday, there was a cornice fall involving Bigfork students on a field trip to Three Bears Lake, immediately north of the railroad tracks at Marias Pass. Two Bear Air, Alert and Glacier Park responded with 2 or 3 students transferred to an area hospital Apparently students were on top of the cornice and triggered the collapse.  The terrain in this area is flat to gently rolling within a lodgepole pine forest.  We are assuming recent westerly winds scoured the lake surface and deposited snow at the east end of the lake where an annual cornice forms. We will update this account as we receive more information.

This seasons fluctuating weather patterns have left us with fluctuating snowpack stability and variable riding conditions. This is not your straight forward NW MT snowpack that is deep, warm and strong but instead has touches of Coastal Mountains (rain) and Colorado (persistent slab). This is a good year to dig into the pack and see these unique problems... in hopes that we won't see them again for awhile. This is also a good year to practice your rescue skills while waiting for our snowpack to strengthen. FAC is hosting a companion rescue clinic with an evening session at RMO February 9 and a field day at the Hungry Horse Ranger Station February 10. Check out this link for the info. This is a great class to learn what to do if something goes wrong. Guaranteed you will walk away much more confident of your rescue skills after this session!

Ladies Avalanche Awareness Talk - Kalispell Brewing Company -  January 30                                                                                                                                                                                                      Join us at Kalispell Brewing Company, at 6:30 pm for a free, engaging, and entertaining 1 hour avalanche awareness presentation with FAC Education Coordinator Jenny Cloutier. The presentation is a great way to refresh your avalanche knowledge or a great introduction to avalanche safety. The class includes general information about avalanche hazard, how to avoid it, and proper equipment for traveling in avalanche terrain.  

Weather and CURRENT CONDITIONS
weather summary

Light to moderate snowfall with rising snow levels will continue through the day. Winds will continue out of the south/southwest at 10-20 mph with gusts in the mid-30s. Look for stronger wind gusts as you approach the Continental Divide. A cold front moves through the region late tonight/early tomorrow. 

Two-Day Mountain Weather Forecast Produced in partnership with the Missoula NWS
For 5000 ft. to 7000 ft.
Wednesday Wednesday Night Thursday
Cloud Cover: Continued snow with rising snow levels. Light snow showers. Cooler temps. light/moderate snowfall.
Temperatures: 31-36 deg. F. 21-26 deg. F. 26-32 deg. F.
Wind Direction: S/SW S/SW SW
Wind Speed: 10-20 with gusts to 25 10-20 with gusts to 25 10-20 with gusts to 30
Snowfall: 2-5 in. 1-2 in. 2-3 in.
Snow Line:
Disclaimer

This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.