GNFAC Avalanche Advisory for Thu Mar 16, 2017

Not the Current Forecast

Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Thursday, March 16th at 6:45 a.m. Today’s advisory is sponsored by Excel Physical Therapy and Cooke City Super 8/Bearclaw. This advisory does not apply to operating ski areas.

Mountain Weather

At 5 a.m. mountain temperatures range from the upper 20s to low 40s F and winds are blowing 20-40 mph out of the W-SW with stronger gusts pushing 50 mph. Today, a quick moving front will impact the area bringing an increased chance of rain and wet snow. Rain will likely fall up to 8,000 ft. with wet snow falling above that elevation. Temperatures today will warm into the 30s to low 40s and winds will remain moderate to strong out of the W-SW. Precipitation moves out of the area this evening and tomorrow looks to be dry with cooler temps.

Snowpack and Avalanche Discussion
Bridger Range Madison Range Gallatin Range Lionhead area near West Yellowstone Cooke City

Today, wet snow avalanches are the primary concern. Below 9,000’, temperatures have not dropped below freezing for multiple days (video). The lack of freezing temps combined with the potential for rain today will produce unstable conditions, mainly on mid to low elevation slopes. Obvious signs on instability such as roller balls and point releases are Mother Nature’s clues that conditions are destabilizing (photo). On slopes above 9,000’, cooler temps, cloudy skies and strong wind will help reduce the wet snow avalanche hazard.

An additional problem will be falling cornices (photo). These massive, overhanging chunks of snow are losing strength and breaking (photo). Give these monsters a fair distance both on and below the ridgelines.

Today, the wet snow avalanche danger on mid to low elevation slopes will start out MODERATE, but could rise to CONSIDERABLE with warming temps and the potential for rain. In upper elevation terrain, both the wet snow and dry snow avalanche hazard is LOW.

Check out our Photo page for many recent pictures of cornice triggered avalanches and slides in wind-loaded terrain.

I will issue the next advisory tomorrow morning by 7:30 a.m.

We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.

03 / 15 / 17  <<  
 
this forecast
 
  >>   03 / 17 / 17