GNFAC Avalanche Advisory for Mon Mar 1, 2010

Not the Current Advisory

Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, March 1, at 7:30 a.m.  Gallatin County Search and Rescue, in cooperation with the Friends of the Avalanche Center, sponsor today's advisory.  This advisory does not apply to operating ski areas.

Mountain Weather

A strong ridge of high pressure has parked over southwest Montana and put the e-brake on, eliminating any chance of precipitation.  Temperatures have been spring like over the past 24 hours, with above average highs in the 40's F and lows in the 20's F.  Light winds out of the S-SW at 5-10 mph were actually welcomed to help offset the warm temperatures in the upper elevations.  Today will be even warmer than yesterday with highs reaching almost 50 degrees F and lows barely dropping below freezing.  Winds will remain light out of the S-SW at 5-15 mph.

Snowpack and Avalanche Discussion

The Bridger, Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range:

The lack of snow over the past week has had differing effects.  The snowpack has enjoyed this hiatus from precipitation since the lack of a recent load has allowed for some strengthening to occur.  However, from a human standpoint it has increased the stress on powder hungry minds and has sent riders far and wide in search of the last remnants of soft snow.  As we travel further and deeper into the backcountry in search of powder, we end up exposing ourselves to steeper and more dangerous avalanche terrain.  This creates the confusing task of facing a snowpack that still holds the potential for producing avalanches but at the same time is showing small signs of improvement.

The fact is, a lack of recent snow and spring like temperatures may give a false sense of security when approaching avalanche terrain. Weak snow still exists on nearly every slope in every range throughout our advisory area.  Near surface facets 1-2 feet below the surface exist on most slopes with a south facing aspect while buried surface hoar exists on a nearly all slopes with a north facing aspect.  These thin but sensitive weak layers will react to stress provided by a skier or rider and could potentially produce dangerous avalanches.  A smaller but still important detail to pay attention to on south facing slopes, is the possibility of a point release or wet slide occurring.  These smaller, but still dangerous slides will most likely occur on steep south facing slopes exposed to rocks and cliffs and will generally take place from late morning to late afternoon as the sun heats up the snow surface.   As south facing slopes get cooked by the sun and become less desirable to ride, the north facing slopes that hold the last scraps of powder will become the ones to be wary of.   With buried surface hoar being consistently found 1-2 feet below the surface on north facing slopes, these runs should be approached and evaluated with caution before dropping in.  Despite the fact conditions feel much more like spring than winter, human triggered avalanches remain possible and the avalanche danger is rated MODERATE.            

Doug will issue the next advisory tomorrow morning at 7:30 a.m. If you get out in the backcountry let us know what you find.  You can reach us at 587-6984 or email us at mtavalanche@gmail.com

Avalanche Education & Events 

1.    Bozeman

Join us to discuss the snowpack, weather, and circumstances leading up to the avalanche on Saddle Peak.  We will show videos, pictures, and share stories about this popular sidecountry destination. Cost: Free, When: Thursday, March 4 from 6:30-7:30 p.m., Where: Bozeman Public Library meeting room. 

2.    Bridger Bowl

29th Annual Pinhead Classic on Saturday, March, 6th.  "Carnival" is this year's costume theme, so come dressed up to race, socialize and win great prizes. Registration fee is $30 but gets you all sorts of cool stuff. Check out the website http://pinheadclassic.com for details. 

3. Moonlight Basin

Comprehensive avalanche awareness class - Thursday, March 4th to Saturday, March 6th

events@moonlight.com or 406-993-6026


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