Avalanche: Slide Canyon

Observer Name
Woody
Observation Date
Friday, March 23, 2018
Avalanche Date
Friday, March 23, 2018
Region
Provo » Provo Canyon » Slide Canyon
Location Name or Route
Slide Canyon
Elevation
10,400'
Aspect
Northeast
Slope Angle
43°
Trigger
Explosive
Trigger: additional info
Intentionally Triggered
Avalanche Type
Hard Slab
Avalanche Problem
Persistent Weak Layer
Depth
3.5'
Width
2,500'
Vertical
4,500'
Comments

Storm on the 22nd to 23rd produced moderate to heavy rain up to 10000'. Winds remained strong out of the SSE for the first half of storm with winds peaking around 4-5am on the 23rd. No snow to transport due to previously wind scoured fetch and only rain falling prior to slide. One thing of note is that the precip site at Mid Mtn only recieved .39" of precip while Aspen Grove recieved 1.66" of rain during the same period. Prior to this avalanche we noted on an adjacent test slope 2m of snow just below the ridges and 1.5m of snow mid slope with a persistent week layer buried on average 80cm below the surface (top 80cm was 1F-P hard) that was showing moderate to hard propagation results with ECT tests, but moderate results on PST and Compression tests. Taking just the one start zone into account we classified this slide as a HS-AA-R3D3- G/O. Crown measured 2700' in length. Average crown depth of 3' with the deepest being 6-10' deep. Vertical Fall 4700'. (last 1300' vertical of the track did not have snow in it prior to the avalanche) Toe of the debris terminated at 5700' MSL.

Comments

Note how far up the sides of the gully that the avalanche traveled. as it moved through the track. Towards the the upper section of the track the avalanched banked several hundred feet up the side of the slope as the drainage turned sharply.

Coordinates