Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Thursday, March 23nd at 6:30 a.m. Today’s advisory is sponsored by Yellowstone Club Community Foundation and Montana Ale Works. This advisory does not apply to operating ski areas.
Overnight the mountains around Cooke City picked up 1-2” of new snow. This morning temperatures are in the mid to upper 20s F and winds are blowing 5-15 mph out of the W-NW. Today, skies will be partly to mostly cloudy and temperatures will warm into the mid to upper 30s F. Winds will continue to blow 5-15 mph and shift to the W-SW. A ridge of high pressure builds over the area tonight, which will produce sunny and warm conditions tomorrow.
It’s a choose your own adventure type of day. Dry snow still exists on high north facing slopes while spring corn conditions can be found if timed right on south facing and lower elevation terrain.
The snow will change quickly today. A surface crust that formed overnight due to below freezing temperatures will break down when exposed to warmer temps and sun. This will produce poor travel and increasingly unstable conditions video. We had an observation of skiers who found themselves slogging for over three hours to cover what would normally take a half hour due to isothermal snow conditions. My partner and I found similar conditions when skiing out of Beehive Basin around 1 p.m. yesterday video. In the Bridger Range, a large wet loose avalanche was observed on Bridger Peak yesterday. It started as a small point release in an upper elevation rock band, but grew in size as it traveled down a majority of the slide path.
With a good freeze overnight, wet snow avalanches won’t be a problem until late morning-early afternoon. If skies stay cloudier than expected, wet snow instabilities shouldn’t be a problem above 9,000 ft. If the sun comes out in earnest, roller balls and point releases will be an issue on sun exposed slopes (photo, photo). If these signs of instability are present, it will be best to move to shadier aspects or away from steeper terrain.
For today, the wet snow avalanche danger will start out LOW in the morning and rise to MODERATE as the day heats up, especially on sun exposed slopes and mid to low elevation terrain. The dry snow avalanche danger on high north facing slopes is LOW.
CORNICE DANGER
Cornices are extra big this year (photo) and the warm temperatures will weaken their grip on the ridgelines. They can break far from the edge and can trigger large avalanches like this one observed last week in the Bridger Range (photo).
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.