GNFAC Avalanche Forecast for Sun Apr 7, 2013

Not the Current Forecast

Good morning. This is Doug Chabot with the season’s 136th and final Avalanche Advisory issued on Sunday, April 7 at 7:30 a.m. This advisory does not apply to operating ski areas.

Thank you to the Friends of the Avalanche Center, the Big Sky, Bridger, Moonlight Basin, and Yellowstone Club ski patrols, Gallatin Snow Rangers, and everyone who sent us observations or made a contribution.  The list is endless, and our advisories would not be possible without your help. 

Mountain Weather

The freezing line dipped to 7,000 feet last night. This morning the Bridger Range and Big Sky area have two inches of new snow while other areas received up to four inches.  At 5 a.m. winds are blowing west at 15-30 mph under partly cloudy skies.  Cloud cover will increase this morning bringing scattered snow showers throughout the day.  Later tonight, winter will return for an encore. Temperatures will drop into the teens and 4-6 inches will fall in the mountains by mid-morning tomorrow.

Snowpack and Avalanche Discussion

Bridger Range   Madison Range   Gallatin Range   

Lionhead area near West Yellowstone   Cooke City

In the last 48 hours close to an inch of Snow Water Equivalency fell in the Gallatin and southern Madison Ranges and mountains outside Cooke City (about 8-10 inches).  The Bridger Range and Big Sky area got half that.  A 2-3” frozen ice crust under this new snow can easily support this load.  On high elevation north-facing terrain the crust is absent, but the snowpack has good stability.

For today, avalanche activity will be confined to windblown snow.  Use extra caution before dropping in off the ridgelines. Avalanches will move faster and further than expected because of the underlying hard crust. Although I do not expect natural avalanches, human-triggered ones are still possible. For today, the avalanche danger is rated MODERATE on wind-loaded terrain and LOW everywhere else.

This weekend the riding and skiing conditions have greatly improved along with the avalanche danger.  The grimmest part of the day will be navigating past the frozen mud at the trailheads.  SPOILER ALERT: Low elevation snow will have a thin crust, but don’t worry, you can still crash through the soggy snow to the ground! Sorry to ruin the surprise.

Mark, Eric, and I thank you for your support, observations, feedback and encouragement.  You are the reason we are here.  After today’s advisory we will post a few things to keep in mind for spring. Stay in touch and drop us a line at mtavalanche@gmail.com or 587-6984.  See you in the fall and have a great summer.

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