Date of Observation: 03/27/2023
Name: billy barr
Zone: Southeast Mountains
Route Description: Gothic townsite
Observed avalanche activity: No
Weather: Second verse, same as the first. Obscured cloud cover with light, dense snowfall, most in the past 24 hours coming between sunset and around 2 a.m. with 3½” new snow and water 0.34″. The snowpack is back at 94½”. Light wind with some gusting and cool with the high 21, low 4 and the current 5.
6164
Date of Observation: 03/26/2023
Name: Zach Guy
Zone: Northwest Mountains
Route Description: Pittsburg to 11,600′ saddle between Schuylkill Ridge and Schuylkill Mtn, traveling mostly on north and northeast aspects.
Observed avalanche activity: Yes
Avalanches: A large (D2.5) debris pile off the north side of Schuylkill Ridge appeared to run Friday night or Saturday, based on minimal fresh snow on the debris. We traced the lookers right side of the debris lobe, which knocked over a few small trees. The combination of flat light and recent drifting near ridgetop made it difficult to make out the crown.
Weather: Unseasonably cold. Light winds. Very light snowfall and overcast most of the day.
Snowpack: About 6″ of recent snow from Friday night, with notable wind affect near treeline. No signs of instability underfoot except for some minor cracking about 8″ deep in drifted terrain. Stability tests on both north and southeast aspects near treeline produced hard, non-propagating results on the 3/20 interface, which is small, rounding facets buried about 60 cm deep.
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6163
Date of Observation: 03/25/2023
Zone: Northwest Mountains
Route Description: Slate River
Observed avalanche activity: Yes
Avalanches: Small skier-triggered avalanche. NE.9,400ft.
Photos:
6162
The weekly summary is here. The previous weekend’s mild weather gave way to a week full of storms. Total snowfall for most areas was over 20″ by the weekend. Avalanche activity for the week was characterized by widespread storm slab action, a natural cycle that produced several large avalanches, and one of the biggest remotely triggered avalanches of the season on Baldy.
Weekly Summary March 17-23, 2023 (1) COMPRESSED
Date of Observation: 03/25/2023
Zone: Northwest Mountains
Route Description: Anthracite Range. NW Mountains.
Observed avalanche activity: Yes
Avalanches: We remote triggered at least 3 very large avalanches on southeast to south-facing terrain above the Beaver Ponds. We were choosing to ski northerly-facing terrain, but while skiing down the ridge to a second lap on the back of the ridge, we felt a collapse, and watched three very large (D3) avalanches run to near their vegetative trim lines.
Weather: Cold, mostly cloudy, breezy. We did not see much snow transport during the day, but it looked like snow drifted overnight.
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6161
Date of Observation: 03/25/2023
Name: Evan Ross
Zone: Southeast Mountains
Route Description: Brush Creek out to Teo
Observed avalanche activity: Yes
Avalanches: East, 9,700ft. Remotely triggered a small avalanche from a couple of hundred feet away. This was a wind-loaded terrain feature and a lot of the feather isn’t steep enough to avalanche. The crown is estimated to be 60 to 70cm thick. I didn’t get to check the crown.
East, 10,100ft. Remotely triggered a D1.5 from 15 feet away. The avalanche propagated above and into steeper terrain. The slab was 65cm thick and around 280 feet across. The weak layer was the 3/20 crust collapsing into the 3/15 crust. The average slope angle of the bed surface was 40+ degrees.
Weather: Obscured with poor visibility. Light to moderate winds at lower elevations. I wore 2 down coats and a shell, must be getting soft.
Snowpack: Hunting some obvious signs of instability and they were somewhat hard to find. In general, the faceted crusts in the upper snowpack were similar to those in the NW Mountain forecast area. On some occasions, I got results with last week’s storm snow failing on the 3/20 crust, and in others, the 3/20 crust was collapsing into the 3/15 crust. I only got two notable collapses while traveling through the terrain. HST since yesterday was 4″. Visibility was poor, but what below treeline terrain I could see didn’t have a notable natural avalanche cycle last week.
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6160
Date of Observation: 03/25/2023
Name: Zach Guy
Zone: South of forecast area
Route Description: Rec tour, Spring Creek area. SE to NE aspects BTL
Observed avalanche activity: Yes
Avalanches: A recent persistent slab on a west facing slope BTL.
Weather: Mostly cloudy, very light snow. Unseasonably cold. Moderate winds in exposed terrain.
Snowpack: Snowdepth was around 100 to 130 cm. We got a couple of large collapses that appeared to fail mid pack, below about 60 cm of slab-forming snow that has fallen in March. The weak layer was facets (F) with one or multiple crusts above. These were on low angle southeast slopes; more representative of what I would expect to find on steep east.
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6159
Date of Observation: 03/25/2023
Name: Evan Ross
Zone: Southeast Mountains
Route Description: Gothic
Weather: Moderate to heavy snow after dark stopping around midnight with 6″ new and water 0.54″. The snowpack is at 95″ deep, just below the winter’s deepest of 97″ but the past 4 days have been the deepest snowpack on record for these dates. A steady 4-8 mph west wind with gusting to 15 as temperature slowly drops. After a high yesterday of 32 it is currently the days low of 3 with a cloudy sky (now and for forever it seems).
6157
Date of Observation: 03/24/2023
Name: Evan Ross
Zone: Northwest Mountains
Route Description: Slate River. Variety of aspects. Mostly stayed within 500 hundred feet of the valley floor.
Observed avalanche activity: Yes
Avalanches: Many of the avalanches in the Slate and upper Slate have already been documented. I targeted specifics on those weak layers and that info is below. Avalanches on easterly aspects had the largest propagation and the most number of avalanches. However Northerly and westerly aspects had their share. The crowns in the alpine appear to be drifted back over or not visible with the recent weather.
I remotely triggered one large slab avalanche from a few hundred feet away, while traveling on a low-angled slope below. The avalanche ran on a west-facing aspect at 9,700ft. Later that day I found a D1 natural that ran today on another West aspect. These avalanches appeared to run on top of the 3/20 crust.
The NE to E Happy Chutes and Climax chutes had a handful of D1.5 to D2 slab avalanches from the last storm. The crowns were most commonly on the steep 40 to 40+ degree rollers in the terrain.
Weather: Calm to light wind in the valleys. Notable blowing snow off the high peaks in the later afternoon. Mostly cloudy and warm.
Snowpack: I targeted several old avalanche crowns to get a better sense of whether the recent avalanche cycle was breaking in non-persistent storm snow or the well-documented persistent weak layers in the upper snowpack. In each crown I checked out, the avalanche had broken on or below the 3/20 interface, before using the 3/15 interface as a bed surface.
On Easterly facing slopes, the 3/20 interface is a collapsible crust about 1cm to 3cm thick, and the avalanche activity on these aspects had propagated widely across the terrain. The 3/15 interface just made for a nice bed surface on all these avalanches. The crown heights were typically 45 to 65cm.
Where the 3/20 interface was NSF, on northerly facing slopes, the avalanches didn’t propagate as wide.
On westerly aspects, the upper snowpack structure is similar to that found on east aspects. I targeted one test pit on a west aspect 10,500ft, and got an ECTP 23 result on the 3/20 interface. Later I got the remotely triggered avalanche on another west aspect and saw the small nature on another west aspect.
I didn’t observe any obvious signs of instability. The upper slab has settled and gained strength.
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6156
Date of Observation: 03/24/2023
Name: Cosmo Langsfeld
Zone: Southeast Mountains
Route Description: Cement Creek Rd
Observed avalanche activity: Yes
Avalanches: Fresh looking slide on Cement Mtn north bowl. NE-ish aspect, maybe some of the E facing terrain as well. Looks like it began in wind loaded terrain up high and stepped down into a deeper layer part way down the path. Spotted Friday morning.
Weather: Partly cloudy.
Snowpack:
Photos:
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