Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Wednesday, April 4th at 6:30 a.m. Today’s advisory is sponsored by the Bridger Bowl and Cooke City Motorsports. This advisory does not apply to operating ski areas.
Since yesterday morning the mountains near West Yellowstone and Cooke City picked up 1-2”
of new snow while the rest of the advisory area remained dry. At 5 a.m. temps are in the teens to low 20’s F and winds are blowing 15-35 mph out of the W-SW. Today, temps will warm into the upper 20’s to low 30’s F and winds will remain moderate to strong out of the W-SW. Skies will be cloudy throughout the day and there’s an increasing chance of snow this afternoon and evening. By tomorrow morning the mountains will see 2-4” of new snow.
Wind slabs are the primary concern across the advisory area. On Monday, wind loaded slopes failed naturally and with human triggers (video, photo). Yesterday, calmer and drier conditions gave wind loaded slopes a chance to gain strength. On our tour in Beehive Basin yesterday, we found wind loaded slopes to be less reactive (video), which is consistent with observations from both Big Sky and Bridger Bowl Ski Patrols.
However, a separate observation form the northern Madison Range reported a wind loaded slope being remotely triggered by a skier’s dog (photo). This slope was heavily loaded by west-southwest winds. This is bull’s eye information that wind loaded slopes should be evaluated carefully and deserve respect.
Watch for areas of wind drifted snow near upper elevation ridgelines and cross loaded terrain features. Cornices are visual clues that underlying slopes could be heavily wind loaded. Use quick hasty pits or small test slopes to evaluate stability before committing to consequential terrain.
Outside of wind loaded slopes the snowpack is generally stable.
Today, human triggered avalanches are possible on wind loaded slopes which have a MODERATE avalanche danger. Non-wind loaded slopes have a LOW avalanche danger.
If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Info and Announcements
Our last daily advisory will be this Sunday, April 8th. Afterward, we will issue weather and snowpack updates on Monday and Friday mornings for most of April.
Hyalite Canyon road is closed to vehicles and reopens May 16th.
Send us your observations on Instagram! #gnfacobs
Posting your snowpack and avalanche observations on Instagram (#gnfacobs) is a great way to share information with us and everyone else this spring.