Mar 27, 2018 @ 6:21 am

The avalanche danger for the West Central Montana backcountry is LOW. Small avalanches are possible in isolated areas and extreme terrain. Carefully identify features and snow that have the potential to slide before traveling in steep terrain.

Good morning, this is Logan King with the West Central Montana Avalanche Center’s avalanche advisory for Tuesday, March 27th, 2018.  This danger rating does not apply to operating ski areas, expires at midnight tonight and is the sole responsibility of the U.S. Forest Service.

Weather and Snowpack

Mountain temperatures this morning are in the mid to upper twenties. Scattered snow showers have deposited 1-2 inches of snow across the advisory area with isolated areas receiving up to 5 inches. Mountain winds have been predominantly out of the West and sustained in the 20’s with gust into the 30’s.

Travis and I rode near granite Pass yesterday. We found about 3 inches of snow that had fallen on a hard melt-freeze crust. Temperatures yesterday were colder, and strong westerly winds persisted through the day.

Wind slabs are the most significant avalanche concern today. New snow and strong winds have created thin wind slabs that have not bonded to the crust. Wind slabs are small and only 3-10 inches thick but can be dangerous in areas with terrain traps. Be wary of venturing onto steep wind-loaded terrain and seriously consider the consequences of getting caught in an avalanche.

It’s easy this time of year to let your guard down, but don’t be lulled into complacency by the low ratings. Conditions can and do change rapidly this time of year so continually evaluate the avalanche danger and problems if you are in traveling in the mountains. Continue to utilize good travel practices and adapt plans according to conditions.

Avalanche and Weather Outlook

Scattered showers are expected to continue today with minimal accumulations while the rain line will slowly climb to about 5,000 feet. Strong westerly winds look to continue through the day today. Avalanche activity will remain steady, but the size of wind slabs will increase in areas that pick up more snow. Another round of snow is on tap for tonight and into tomorrow.

The next advisory will be issued on March 29th, 2018.

If you are out in the backcountry, please send us your observations, these are very helpful in producing the advisory.

Ski and ride safe.


Problem 1 - Wind Slabs

  • TYPE


    Wind Slabs

    Release of a cohesive layer of snow (a slab) formed by the wind.  Wind typically erodes snow from the upwind sides of terrain features and deposits snow on the downwind side.  Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

  • SIZE


    1 (Small)

    The potential size of avalanche resulting from this problem.




    The likelihood of an avalanche resulting from this problem.

Thin wind slabs can be triggered on wind loaded terrain.


Observations Granite Pass 03/26/2018

Observations Granite Pass 03/26/2018


Scattered showers today will be accompanied by strong westerly winds. Another round of snow will move into the region tonight and into tomorrow.

This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but the information can help you make a more informed decision regarding travel in avalanche terrain for the next few days.

Our advisory area includes National Forest System lands in the Bitterroot Mountains from Lost Trail Pass north to Granite Pass, the Rattlesnake Mountains north of Missoula and the Southern Swan and Mission Mountains near Seeley Lake, MT. Avalanche information for the Lookout Pass/St. Regis Basin area is available from the Idaho Panhandle Avalanche Center.