THIS AVALANCHE FORECAST EXPIRED ON January 20, 2019 @ 12:05 am
Avalanche Forecast published on January 19, 2019 @ 7:05 am
Issued by Clancy Nelson - Flathead Avalanche Center

Whitefish Range

How to read the forecast

A Special Avalanche Bulletin remains in effect until this evening. Thin, soft storm slabs continue to develop on top of lower density snow, buried weak layers, and crusts. It is possible to trigger avalanches in steep terrain, especially in areas with buried surface hoar. Watch for shooting cracks and collapsing as clues that direct you to less steep slopes.

2. Moderate

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Above 6500 ft.
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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5000-6500 ft.
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

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.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
  • 1. Low
  • 2. Moderate
  • 3. Considerable
  • 4. High
  • 5. Extreme
Avalanche Problem 1: Storm Slab
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    Certain
    Very Likely
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  • Size ?
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6 to 8” of new snow continues to load weak surface hoar, facets, and crusts. These layers exist at all elevations but are most prevalent and weakest at middle elevations. Storm slabs failing on these layers could propagate farther across the slope than expected. Be extra cautious of areas that received more snow or windloading. Shooting cracks are a red flag. 

Avalanche Problem 2: Deep Slab
  • Type ?
  • Aspect/Elevation ?
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    Certain
    Very Likely
    Likely
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Thick slabs have broken on deeply buried weak layers with every major storm cycle this winter.  The most recent was a number of very destructive slides that broke up to 5 feet deep at upper elevations in the Flathead Range and Glacier Park. These slides have been commonly triggered by cornice falls or small avalanches in the upper snowpack.  As new loading continues today, with an expected uptick in avalanche activity, be extra cautious of overhead hazards from alpine start zones.  Choose terrain that minimizes your exposure below steep, rocky, variable start zones.

Forecast discussion

A Special Avalanche Bulletin remains in effect through this evening. Dangerous avalanche conditions exist in parts of the forecast area. In other areas, avalanche danger is heightened at a minimum. Conservative decision making is essential for your safety this weekend.

New snow between 6 and 10” has fallen since Thursday. The Swan Range continues to receive the most new load. As showers continue throughout today, existing slabs with thicken, become more cohesive, and may break in unpredictable ways. Southwesterly winds are expected to increase near the Divide. Fragile layers of surface hoar, facets, and crusts that developed during high pressure last week are now sensitive buried weak layers. New avalanches may fail in surprising ways and be larger than expected under these conditions. Slabs can break above you on the slope. Consider overhead hazards and new loading continues to add weight to deeply buried, old weak layers at the bottom of the snowpark.

 

Weather and CURRENT CONDITIONS
weather summary

A weak disturbance pushes though the area today with a few inches of new snow, light to moderate snowfall, and gusty winds this afternoon over the Divide.

Two-Day Mountain Weather Forecast Produced in partnership with the Missoula NWS
For 5000 ft. to 7000 ft.
Saturday Saturday Night Sunday
Cloud Cover: Overcast Mostly Cloudy Overcast
Temperatures: 30 to 35 deg. F. 23 to 28 deg. F. 25 to 30 deg. F.
Wind Direction: SW SW S
Wind Speed: 15 to 25 mph, gusting to 35 mph 10 to 20 mph, gusting to 30 mph 5 to 15 mph, gusting to 25 mph
Snowfall: 2 to 4 in. O to 2 in. 2 to 4 in.
Snow Line: 4000 FT 3000 FT 3000 FT
Disclaimer

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