22-23

Various Avalanche Problems

Date
Activity
Snowmobiling

We rode through Second Yellow Mule, and then we headed back towards Cedar Creek. There was 2-4" of new snow throughout the area. Next, we rode to Bear Creek and dug a pit. We dug on an east facing aspect, and there was ~4 feet of snow (HS = 130 cm). We had an ECTX. Despite the crust and some warmer temps before today, the snowpack is still dry throughout, and there are still facets in the bottom half of the snowpack. During our ride we were looking for recent avalanche activity, and we only saw a couple of small point releases. We are still concerned about large, unsurvivable avalanches breaking on the weak layers deeper in the snowpack.

Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
Ian Hoyer, Alex Haddad

Hellroaring Creek Avalanche Cycle

Hellroaring Creek
Island Park
Code
N
Latitude
44.54900
Longitude
-111.47500
Notes

Toured into the hellroaring creek 3/15-3/19. Snowing and blowing hard on 3/15 till approx 1500 hrs when wind veered to the north and skies cleared for the rest of the trip with generally cold temps and light winds. Solar aspects heating up in the day with extensive sun crusting on steeper slopes facing the south half of the compass. Observed aftermath of extensive avy cycle(s) one of which prior party reported occurred approx 3/10-11 at higher elevations on Nemesis (above 8000 ft.). And another on lower elevation steep slopes above creek at approx 7500 ft that may have ran during the storm on 3/14 as less snow covered that debris than the higher elev runouts. Everything observed were on westerly aspects and deep slab avalanches breaking approx 90-120 cm down. We did not investigate the weak layer. Suspect it to be the crust facet combo observed by a previous party in early March. Heavy wet snow possibly mixed with rain on 3/14-15 likely tipped the scales for these lower elevation slopes below 7500. No signs of instability of the new storm/wind slab during the five day trip, however we did get a few large collapses but these were isolated to heavily wind loaded areas in more exposed terrain. No other natural or human triggered avalanches observed during the trip. Many machiners were out testing steep slopes after the storm and we saw no signs of any human triggered avalanches. We did not measure height of snow but judging by the buried hut and the non-motorized boundary signs barely poking out of the snow, thinking about 10 feet deep at 8000 ft.

Number caught
0
Number buried
0
Trigger
Natural trigger
Problem Type
New Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Hellroaring Creek Avalanche Cycle

Hellroaring Creek
Island Park
Code
N-R3-D2.5
Latitude
44.54900
Longitude
-111.47500
Notes

Toured into the hellroaring creek 3/15-3/19. Snowing and blowing hard on 3/15 till approx 1500 hrs when wind veered to the north and skies cleared for the rest of the trip with generally cold temps and light winds. Solar aspects heating up in the day with extensive sun crusting on steeper slopes facing the south half of the compass. Observed aftermath of extensive avy cycle(s) one of which prior party reported occurred approx 3/10-11 at higher elevations on Nemesis (above 8000 ft.). And another on lower elevation steep slopes above creek at approx 7500 ft that may have ran during the storm on 3/14 as less snow covered that debris than the higher elev runouts. Everything observed were on westerly aspects and deep slab avalanches breaking approx 90-120 cm down. We did not investigate the weak layer. Suspect it to be the crust facet combo observed by a previous party in early March. Heavy wet snow possibly mixed with rain on 3/14-15 likely tipped the scales for these lower elevation slopes below 7500. No signs of instability of the new storm/wind slab during the five day trip, however we did get a few large collapses but these were isolated to heavily wind loaded areas in more exposed terrain. No other natural or human triggered avalanches observed during the trip. Many machiners were out testing steep slopes after the storm and we saw no signs of any human triggered avalanches. We did not measure height of snow but judging by the buried hut and the non-motorized boundary signs barely poking out of the snow, thinking about 10 feet deep at 8000 ft.

Number caught
0
Number buried
0
Trigger
Natural trigger
R size
3
D size
2.5
Problem Type
New Snow
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Skiers in the Hellroaring Creek area of the Centennials got a good view of the aftermath of an avalanche warning on March 14 and 15. They saw many avalanches that broke 3-5 feet deep. This is one of many west-facing steep slopes above the creek that ran. Photo: A. Dunn

Island Park, 2023-03-21

Skiers in the Hellroaring Creek area of the Centennials got a good view of the aftermath of an avalanche warning on March 14 and 15. They saw many avalanches that broke 3-5 feet deep. This is one of many west-facing steep slopes above the creek that ran. Photo: A. Dunn

Island Park, 2023-03-21