THIS AVALANCHE FORECAST EXPIRED ON April 6, 2015 @ 12:08 am
Avalanche Forecast published on April 5, 2015 @ 7:08 am
Issued by Todd Hannan - Flathead National Forest

Whitefish Range

How to read the forecast

Generally safe conditions exist in the Whitefish Range. The hazard is LOW, however with a bit of sun today the recent snow may weaken and produce very small, loose, wet avalanches. Thin wind slabs also exist in the upper elevations and it is important to remember that even a small avalanche can be dangerous is consequential terrain. A notable Spring storm that is expected to move into the region tonight and tomorrow will cause the hazard to rise.

1. Low

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Above 6500 ft.
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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5000-6500 ft.
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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3500-5000 ft.
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
  • 1. Low
  • 2. Moderate
  • 3. Considerable
  • 4. High
  • 5. Extreme
Avalanche Problem 1: Wind Slab
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    Certain
    Very Likely
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    Small

Thin wind slabs exist in the upper elevations. Be sure to assess slopes for recent wind slabs and avoid steep, consequential terrain where small avalanches can be dangerous. With a wind shift expected today, we may start to see atypical wind loading patterns late in the day.

Avalanche Problem 2: Loose Wet
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    Certain
    Very Likely
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Periods of sun today are not likely to thaw the thick melt-freeze crust that formed over the past few days. However, it won't take much to sun to moisten the recent snow on top of this crust. We could see surface snow become moist and capable of producing small, loose, wet avalanches late in the day on the sunny aspects. Look for the signs that the sun is affecting the recent snow like roller balls and pin wheels and move to a shaded slope when this begins. Speaking of shaded slopes, recent unconsolidated snow atop the slick melt-freeze crust will easily slide on steep slopes. These loose avalanches will only be as deep as the recent snow, but could entrain quite a bit if they are confined to gullies or consistently steep slopes.

Forecast discussion

 A notable spring storm is expected to move into the area tonight and into tomorrow. The new snow that is expected with the approaching system will cause the hazard to rise. Continue to pay close attention to changing weather and snow pack conditions as we move deeper into Spring. 

This is the last scheduled advisory of the season. Check back tomorrow for a spring avalanche statement.

We would like to thank all of you who helped support the Flathead Avalanche Center this season. Thank you.

recent observations

On Friday, two skiers were caught in a cornice triggered, loose snow avalanche on Appistoki Peak in Glacier National Park, they were carried 200 feet. Thankfully no one was injured. Another skier in the party triggered a wind slab on their descent. Though this incident occurred just outside of the advisory area, it is certainly representative of the conditions that exist locally (observation). 

Yesterday we were on Hash Mountain in the Swan Range, where we found an impressive melt-freeze crust (photo). The crust was nearly a foot thick and easily supported the weight of a snowmobile. There were 5 inches of recent snow atop this crust that easily sluffed on steep slopes. The recent, thin wind slabs in this area were confined to just below the ridgeline and would produce short cracks when approaching the slope (photo).

Weather and CURRENT CONDITIONS
weather summary

Yesterday the Flathead and Swan Ranges picked up 5-6 inches of snow while the Whitefish Range saw 1-3 inches. Currently mountain temperatures range from 17º-22º F and winds are out of the west and northwest at 4-6 mph. Today should see partly/mostly cloudy skies and a few light snow showers early. Winds are expected to shift out of the east at 5-10 mph with gusts in the 20s. Tonight, a storm moves into the area and continues into tomorrow, bringing up to a foot of new snow.

Today’s weather observations near 6000 feet in the region
0600 temperature: 17-22 deg. F.
Max. temperature in the last 24 hours: 30-37 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 5-10 mph
Maximum wind gust in the last 24 hours: 17-25 mph
New snowfall in the last 24 hours: 1-6 inches
Total snow depth: 59-102 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Missoula NWS
For 5000 ft. to 7000 ft.
Sunday Sunday Night Monday
Cloud Cover: Partly cloudy and cool Increased wind and snow Snow showers continue
Temperatures: 31-43 deg. F. 21-30 deg. F. 32-42 deg. F.
Wind Direction: east east east/southeast
Wind Speed: 9 gusts 22-24 14 gusts 25-29 7-8 gusts 17-20
Snowfall: 0 in. 2-3 in. 2 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.