GNFAC Avalanche Forecast for Mon Mar 25, 2013

Not the Current Forecast

Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, March 25 at 7:30 a.m. Gallatin County Search and Rescue in partnership with the Friends of the Avalanche Center sponsors today’s advisory. This advisory does not apply to operating ski areas.

Mountain Weather

This morning there is no new snow to report. Temperatures are in the single digits and winds are blowing 5-15 mph out of the west. Today, skies will be clear and temperatures will warm into the mid to upper 20s. Winds will continue to blow 5-15 mph out of west. A ridge of high pressure will remain parked over the region over the next few days producing clear skies and warmer temperatures. 

Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range   

Lionhead area near West Yellowstone   Cooke City

Some avalanches are predictable and easy to understand, others are not. Yesterday we observed an avalanche north of Ross Peak in the Bridger Range that was a bit of head scratcher. The slide appears to be a natural that propagated hundreds of feet wide and failed on a non-wind loaded slope (photo). This event is an outlier to the generally stable conditions we’ve experienced over the past few weeks.

While difficult to explain, this occurrence is great reminder that avalanches remain possible during a low to moderate danger. Digging snowpits and evaluating terrain carefully regardless of the overall stability is a sensible way to approach avalanche terrain. 

Yesterday, Doug and his partner toured in Beehive Basin and conducted multiple stability tests to confirm that conditions were stable (video). Skiers also dug snowpits and found a stable snowpack on Mt Ellis. 

Without new snow and wind, generally stable conditions will persist. However, there are few problems to consider. Previously wind loaded slopes; specifically those in steep, upper elevation terrain should be approached with caution (photo). Also, wind loading and cornices go hand in hand. Avoiding areas both above and below large cornices is a good way to eliminate unexpected surprises (photo).

In addition, clear skies and strong solar input will make wet loose slides possible on steep, sunny slopes. Signs of instability such as roller balls and point releases are key indicators the snowpack is losing strength. If these obvious clues are observed, it will be a good idea to move to shadier aspects. 

Today, human triggered avalanches are possible on slopes steeper than 35 degrees which have a MODERATE avalanche danger. Less steep slopes have LOW avalanche danger.           

Doug will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984. 

03 / 24 / 13  <<  
 
this forecast
 
  >>   03 / 26 / 13