Nov 16, 2013 @ 10:53 am

November 16, 2013 Avalanche Information

Hello!  This is Steve Karkanen at the West Central Montana Avalanche Center with early season avalanche information for Saturday, November 16, 2013.

This information is based on limited observations and does not have an avalanche danger rating attached to it.  We plan to begin issuing regular avalanche advisories starting December 15 and continuing every Tuesday and Friday mornings through March.

Until that time, we will post updated early season snow and weather information as conditions change.

The National Weather Service Office in Missoula has issued winter storm warnings and advisories for all of western Montana. The Bitterroot Mountains are receiving significant snowfall today with up to 14 inches possible in the higher elevations by late Sunday.  Higher elevation wind speeds are in the 20 mph range from the south-southwest with associated wind-chill temperatures in the single digits.

Many popular early season destinations in the Bitterroot mountains (and elsewhere) already have plenty of snow to recreate on.  October snowfall on the higher and more sheltered north aspects may have had an opportunity to turn to sugary facets during the dry spells between storms while snow on other aspects was affected by sun and more moderate temperatures.

We received an excellent public observation earlier this week from an experienced backcountry skier who was able to collapse the snowpack on a steep wind loaded couloir near Carlton Ridge. His observation indicated that recent snow failed at the interface with the older snow surface where facets formed during one of the earlier dry/cool periods.

Recently wind loaded terrain and cold shaded aspects where facets may have formed near the bottom of the snowpack or on an older snow surface are the primary things to be aware of and look for right now. The only way to know if facets formed on the slope you plan to recreate on is to dig down to the ground. Recent avalanche activity, hearing collapse noise or seeing fracture propagation are clear indicators of unstable conditions.

We like seeing these earlier winter storms pile up.  It helps limit the ability for facets to form at the bottom of the snowpack and leads to stronger overall stability conditions later on.

But early winter is a dangerous time to be caught in an avalanche.  While there may not seem to be enough snow to be a problem, if you do trigger a slide and are caught, you’re going to get beat up by rocks, small trees, brush and anything else sticking out of the snow. Your situational awareness must include any terrain or vegetation features that will hurt you if you go for a ride.

Hunters are not immune from avalanches and may be at greater risk as they tend to travel solo and not have the same level of avalanche preparedness as backcountry snowmobilers and skiers. The furthest thing from one’s mind as one tracks an animal across a big open slope is the stability of the snow.  If you are not sure, avoid it.

As I mentioned earlier, our funded operating season begins around December 15.  We will post any public observations we receive so if you get out and see something, send us your observation. Your information is valuable to us and may help to prevent an accident.

We have several classes scheduled and you can review the schedule on our Education and Events page.

Have fun and be safe!


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.