Good Morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Friday, March 24nd at 6:30 a.m. Today’s advisory is sponsored by Gallatin Valley Snowmobile Association and Bridger Bowl. This advisory does not apply to operating ski areas.
This morning mountain temperatures are in the 20s F under mostly clear skies and winds are blowing 10-25 mph out of the W-SW. Skies will remain mostly clear this morning and highs will warm into the low to upper 30s by this afternoon. Increasing clouds and wind impact the area later today as the existing ridge of high pressure breaks down. Wind gusts upwards of 40 mph can be expected at upper elevations later today. Precipitation builds over the mountains tonight and the southern ranges could see 1-2” of snow by tomorrow morning.
Bridger Range Madison Range Gallatin Range Lionhead area near West Yellowstone Cooke City
It’s not snowing but at least it cooled off. Below freezing temperatures overnight combined with clear skies will produce a firm and locked up snowpack during the first half of the day. On all but high north facing slopes, a solid curst will exist on the snow surface creating stable conditions.
As the day progresses, snow conditions will change under the influence of warming temps and sun. If timed right, skiers and riders will enjoy good corn snow as the day heats up. If timed poorly, skiers and riders could endure a slog fest through breakable crust and isothermal mush video. Roller balls and pinwheels are obvious clues the upper layers of the snowpack are becoming unstable video, photo, photo.
One saving grace will be increasing clouds and wind this afternoon. This could reduce the potential for wet snow avalanches, at least at higher elevations. I still expect snow on mid to low elevation slopes to become increasingly unstable as the day progresses.
It's worth noting – a few dry slab avalanches were observed on north facing slopes around Cooke City (photo). This isn’t a widespread problem, but it’s something to consider if you’re skiing or riding in that area.
For today, the wet snow avalanche danger will start out LOW 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 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.