As expected following a big storm and the earthquake, I saw a lot of natural avalanche activity. While most of the avalanches appeared to be "fresh" with little snow covering the debris or crowns, it's impossible to tell whether many of the slides failed before, during, or after the earthquake. That being said, there were some odd patterns of natural activity: observed activity involved middle elevation terrain and the middle/upper elevation transition as much or more than alpine terrain, paths that don't run that frequently ran, and most of the slides appeared to involve the new snow or weak layers buried not very far beneath the new snow. The "unusual" nature of this avalanche cycle leads me to believe many of the slides were triggered by the earthquake. My observations are almost entirely in the Smoky Mtns, and few avalanches were observed in the Boulder Mtns. This may be due to less storm snow in the Boulders, or it could be a function of looking at the west side of the range and not seeing many of the eastern aspects. The most likely explanation is a mixture of both. I lost visibility when I got to Smiley Creek and could only see the "front range" from the Frenchman Ck drainage north. We will post a separate observation for the widespread, impressive northern Sawtooths activity.
Partly cloudy from Ketchum to Smiley Creek. Obscured from Smiley Creek north on the Sawtooths side of the road, partly to mostly cloudy on the White Clouds side.
# | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Comments | Photo |
---|---|---|---|---|---|---|---|---|---|
1 |
Durrance SE 8900 |
D1.5 | SS | N-Natural | |||||
5 |
Goat Ck SE 9400-10000 |
D2 | SS | N-Natural | E, SE, and S aspects. Several soft slabs, some loose snow, and some mixed. Some may be D2.5. | ||||
1 |
N Fork Wood River W alpine |
D2 | U | N-Natural | Could not see crown or where slide originated, just the track. Occurred in wind-affected terrain, so I'd guess a slab was involved. | None | |||
1 |
Newman Ck (Baker) NE 9500 |
D2 | SS | N-Natural | Also saw a D2 mix of loose+SS coming out of the rocks in the next cirque to the north. | ||||
4 |
Silver Lake cirque and Boulder Peak S alpine |
D1 | WL | N-Natural | Some small D1-1.5 dribbles on solar slopes in this area. | None | |||
5 |
Anderson Ck E 9000-9700 |
D2 | SS | N-Natural | |||||
3 |
Prairie Ck E 9600 |
D2 | SS | N-Natural | E-SE aspects, wide slabs triggered by sluffs in most cases. Maybe 2.5 for the biggest one? | ||||
2 |
W Fork Prairie Ck E alpine |
D2.5 | SS | N-Natural | One D2, one borderline D2.5-3 over 500 ft wide. E and SE aspects. | ||||
8-10 |
Owl Ck - Saviers Peak and Bromaghin area E alpine |
D2 | SS | N-Natural | E, SE, and NE aspects. Occurred throughout the storm with some obscured crowns/debris, some partially blown in, and some fresh. Some may be D2.5, hard to tell. | ||||
2 |
Galena Peak W 10000 |
D2 | SS | N-Natural | D1.5-2, one was larger than the other. Cross-loaded starting zones. | None | |||
1 |
Titus Lake (peak above the lake) E 9600 |
D1.5 | SS | U-Unknown | May have been remotely triggered today by skiers who skied the Titus Lake Chutes just uphill of this crown, unknown trigger. Slide could have been D1.5 or D2, could only see the crown. | ||||
3 |
Salmon River Headwaters NE 9300-9800 |
D2 | SS | N-Natural | N and NE aspects | ||||
2 |
Alturas Ck and Beaver Ck NE 9400 and 8800 |
D2 | SS | N-Natural | |||||
1 |
Bromaghin Peak NE 9000-9700 |
D3.5 | U | N-Natural | Some thicker, wind-blown parts of the crown look like they are in the 4-7' range. | ||||
1 |
Guyer Hot Springs - Warm Springs Ck NE 6100 |
D2 | WL | G-Ground | 1-2 feet | N-Natural | Gouging wet loose avalanche that was witnessed during the earthquake at 6 PM on Tuesday, March 31. It crossed the river, took out a few trees. Andrew Dunning photo. | ||
1 |
Big North - Warm Springs Ck NW 7000 |
D2 | WL | O-Old Snow | N-Natural | Mostly surficial wet loose slide that released on 3/30. 3rd hand report says it happened while it may have been raining at that elevation? | |||
1 |
Avalanche Peak E 9300 |
D2 | SS | 18" |
AS-Skier r-Remote |
E-NE aspect. Reliable 3rd hand report of remote skier triggered slide, intentional. Chris Marshall (off duty ski guide) talked to the reporting party and provided the photo. |