Mar 29, 2013 @ 6:59 am

March 29, 2013 Avalanche Advisory

The avalanche danger is LOW (Level 1)  in the west central Montana backcountry.  Natural and human triggered avalanches are unlikely.

Conditions are generally safe, but unstable snow may exist on isolated terrain features.  Isolated pockets of instability may be found in steep, rocky areas where the snowpack is thin or on terrain steeper than 35 degrees exposed to the sun.

Good morning! This is Steve Karkanen with the Friday, March 29,  avalanche advisory from the West Central Montana Avalanche Center.


Weather and Snowpack

Very little (if any) precipitation fell in the mountains since Tuesday.  SNOTEL sites have been recording afternoon temperatures in the forties and fifties with overnight readings dropping below freezing.  This morning, temperatures are just above freezing with 15 mph southwest winds. Temperatures are expected to warm a couple of degrees beyond yesterdays high temperature.

The overall snowpack stability is very good.  Last week’s new snow is well consolidated and has gone through a few melt freeze cycles.

Melt-freeze cycles strengthen snow and can create great skiing and travel conditions. It’s not quite like the corn snow the ski areas now have but it’s close.


What’s Important Now

The biggest hazard will be loose snow avalanches on terrain steeper than 35 degrees during warm afternoons.  Seeing pin wheels, point release wet slides or sinking up to your knees in wet snow are good indicators of changing and possibly more dangerous conditions.  Move to the more shaded and cooler terrain.

Large cornices can be especially touchy and unpredictable during warm weather so avoid walking or riding on or underneath them.


Weather Forecast and Avalanche Outlook

A weak disturbance is moving through the area this morning with widespread shower activity with snow levels above 6000 feet.  A ridge of high pressure will build over the Northern Rockies Saturday and Sunday causing a warming and drying trend. Temperatures will be near to slightly above normal for this time of year. This means freezing temperatures overnight and warm temperatures in the afternoon.

Expect LOW avalanche danger in the morning increasing to MODERATE on steep terrain in the afternoon.


I will issue the final avalanche advisory for the season next Friday, April 5, 2013.  Have a safe and sunny weekend!



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.