Slab avalanches from yesterday’s storm

Date of Observation: 04/16/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Viewed from Slate River Road and Purple Ridge.

Observed avalanche activity: Yes
Avalanches: Schuylkill Ridge saw a wind slab cycle (averaging D1.5) on crossloaded terrain from Northwest winds yesterday. Several other soft slabs above treeline ran during or after the storm yesterday.

Photos:

: Schuylkill Peak. Note widely propagating crown.

: Skier triggered wind slab in Redwell

: Augusta

: Cascade

: Schuylkill Ridge

: Schuylkill Ridge

: Schuylkill Ridge

: Schuylkill Ridge

: Schuylkill Ridge

Avalanche Report #1

Estimated avalanche date: 04/15/2023
Number of Avalanches: 6

Location

Location: Schuylkill Ridge
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: E

Characteristics

Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: New/Old interface

Size

Relative Size: R1 very small
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):

Involvements

# of people caught:
# of partial burials:
# of full burials:

Additional comments: E/NE aspects, numerous bowls.

Avalanche Report #2

Estimated avalanche date: 04/15/2023
Number of Avalanches: 2

Location

Location: Schuylkill Ridge
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: E

Characteristics

Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: New/Old interface

Size

Relative Size: R1 very small
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):

Involvements

# of people caught:
# of partial burials:
# of full burials:

Additional comments: Crossloaded in Great Wide Open

Avalanche Report #3

Estimated avalanche date: 04/15/2023
Number of Avalanches: 4

Location

Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NE

Characteristics

Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:

Size

Relative Size: R1 very small
Destructive Size: D1- Relatively harmless to people
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):

Involvements

# of people caught:
# of partial burials:
# of full burials:

Additional comments: Cascade x1, Mineral/Augusta saddle x 2, Purple Ridge x1

Avalanche Report #4

Estimated avalanche date: 04/15/2023
Number of Avalanches: 1

Location

Location: Schuylkill Ridge
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NE

Characteristics

Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:

Size

Relative Size: R2 small
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):

Involvements

# of people caught:
# of partial burials:
# of full burials:

Additional comments: Impressively wide crown for thin soft slab. Failure date estimated, there’s a chance it ran today.

Avalanche Report #5

Estimated avalanche date: 04/15/2023
Number of Avalanches: 1

Location

Location: Mount Emmons
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NW

Characteristics

Trigger: Skier
Trigger modifier:
Type: Soft Slab
Failure Plane:

Size

Relative Size: R1 very small
Destructive Size: D1- Relatively harmless to people
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):

Involvements

# of people caught:
# of partial burials:
# of full burials:

Additional comments: Redwell Basin

6240