24-25

Small wind slabs and good skiing

Date

Sun, 03/30/2025 - 09:15

Activity

Skiing

Skied the Banana today with 8-12” of new snow that has mostly bonded. The snowpack below the new snow had froze over night and was well consolidated.

Observed a layer of graupel (3-4mm grains) at the new/old interface on the NE ramp starting at 8600’ and clearing up after 8700’. This layer created some reactivity in the storm snow.
Wind slabs <6” had formed on N and NE aspects. We had one small release in the bottom of the couloir measuring ~10x20’ and running ~50’.

Other than that, the skiing was amazing and manageable.

Region

Bridger Range

Location (from list)

Ross Peak

Observer Name

Shep

New Snow in Hyalite

Date

Sun, 03/30/2025 - 12:15

Activity

Skiing

We toured up to Mt Blackmore today and found that winter had returned to the high peaks over the last two days. Since yesterday morning, high elevations around Hyalite have received about 12" of new snow (1.2" SWE). The parking lot had around 3", the trail around 6" and at elevations above 8500' the numbers corresponded well to the Shower Falls SNOTEL.

The parking lot and lower trail softened up throughout the day and temperatures were above 32 degrees at the car at 3pm. In the alpine around 9800', temperatures were just below freezing (31 degrees) around 1pm. Despite our layers and gear getting a bit soggy, the snow from last night remained dry.

A mix of rimed precipitation particles and graupel fell throughout the day. Previous and current winds were calm; there was little to no wind effect on the new snow. we saw no cracking or recent drifts. The 12" of snow since yesterday fell right-side-up and had little to no slab properties. This new snow rests on a stout melt-freeze crust from the high temperatures last week.

Our main avalanche hazard today were dry-loose avalanches. Despite lots of traffic in this zone today, we only saw a handful of slides in steep terrain, and all were relatively small and did not entrain much snow. Conditions can and will change quickly if winds increase or the sun comes out and warms the new snow, but for now, we were happy to find good powder skiing.

Region

Northern Gallatin

Location (from list)

Mt Blackmore

Observer Name

H. Darby

GNFAC Avalanche Forecast for Sun Mar 30, 2025

Snowpack and Avalanche Discussion

Near Bozeman, Big Sky and Cooke City, where more new snow has fallen, avalanches involving the new snow are possible and could slide as wind slab avalanches or loose snow avalanches. Wind has been fairly minimal, but slopes where the new snow has been drifted or stiffened by the wind are more likely to avalanche.

If you plan to travel on steep slopes, assess the stability of the new snow and monitor how it changes throughout the day. Push on small test slopes with clean runout zones to see how the snow reacts. As you travel watch for cracking across the surface as a sign you could trigger slab avalanches, and look for snow being drifted as a sign slabs are growing and possibly becoming more reactive.

Warm temperatures and any sun will make the new snow moist and more cohesive and could cause loose snow or storm slab avalanches to break larger and be easier to trigger. Have a plan to find lower angle terrain or slopes with colder snow if you feel the snow get heavy or moist.

Avalanche danger is MODERATE near Bozeman, Big Sky and Cooke City.

Aside from instability involving the new snow, the snowpack is generally stable. Near Island Park and West Yellowstone, where less new snow has fallen, large avalanches are unlikely. Small wind slab or wet loose avalanches in isolated areas are something to keep in mind. These would only be an issue in extreme terrain where being knocked over would have big consequences, like above cliffs or on long, firm steep slopes.

The avalanche danger is LOW near West Yellowstone and Island Park.

Read more about GNFAC Avalanche Forecast for Sun Mar 30, 2025

Weather and Avalanche Log for Sun Mar 30, 2025

Read more about Weather and Avalanche Log for Sun Mar 30, 2025

Point releases, wet loose in Beehive/Middle Basin

Date

Sat, 03/29/2025 - 09:30

Activity

Skiing

Toured around Beehive and Middle Basins this morning, finding predictably bulletproof snow on most aspects but decent turns aided by the 2-4 inches of snow from last night on northerly terrain that hadn’t been destroyed by the sun this week. There were a few brief moments of direct sun throughout the morning, which almost instantaneously triggered point releases from steeper rocky terrain. On the way back through Beehive we observed some much larger debris piles that weren’t there this morning from the steel rocky face between the Going Home chute and the prayer flags.

Region

Northern Madison

Location (from list)

Beehive Basin

Observer Name

Henry Coppolillo

GNFAC Avalanche Forecast for Sat Mar 29, 2025

Snowpack and Avalanche Discussion

Today is a transition day, between the warmth and mostly dry weather of the last week and the snowy pattern that is setting up for the coming week. This transition leaves us in a bit of a lull today, with large avalanches unlikely and generally safe conditions.

With temperatures below freezing this morning and only expected to get a little above freezing today, the wet snow concerns we’ve been dealing with all week should be minimal. Some areas might not have a stout crust at the surface this morning and in others it might break down today, so do look out for Wet Loose avalanches if you’re sinking more than ankle deep into wet snow. Treed, low elevation slopes facing the southern half of a compass are where you’re most likely to encounter this lingering wet snow.

There is a little bit of new snow this morning and a bit more may fall today, but it won’t be enough to make for much avalanche hazard. There may be some thin wind drifts that could break as small Wind Slab avalanches, but at most, these would only be an issue in extreme terrain where losing your footing or getting pushed a few feet off course would have big consequences.

The avalanche danger is LOW today.

Conditions will be changing with the new snow over the coming days, so make sure to check the again for the latest updates before heading out.