Avalanche: UFO Bowls 2/23/2010

Observer Name: 
Nalli
Observation Date: 
02/23/2010
Occurrence Date: 
02/23/2010
Occurrence Time: 
2:00pm
Region: 
Provo
Provo Canyon
North Fork
UFO Bowls
Location Name: 
UFO Bowl #3
Printer-friendly version

Location

40° 25' 0.4656" N, 111° 37' 46.6824" W
Avalanche Characteristics
Elevation: 
9800'
Aspect: 
Northeast
Slope Angle: 
37
Trigger: 
Unknown
Trigger: additional info: 
Unintentionally Triggered
Avalanche Type: 
Soft Slab
Weak Layer: 
Surface Hoar
Depth (avg): 
14"
Width: 
100'
Vertical: 
800'
People Involved
Caught: 
2
Carried: 
2
Partly Buried: 
1
Injured: 
1
Snow Profile
Snow Profile Comments: 







I went for a violent ride today in UFO Bowl #3 after triggering an avalanche at a steep breakover mid-slope and then being hit by a second slide that was triggered by my partner 500’ above me.  We made many mistakes today and I am lucky to have skied away with just some bumps and bruises and a tweeked knee.  I’ll try to recap things as they happened.

The Provo mountains have received about 14”of new snow with 1”of water over the last week.  This all sits on top of at least one layer of surface hoar that formed on Feb. 8-9.  We have been paying close attention to this for a while now and have given it lots of respect.  Apparently not enough.

 

General Comments







On the way up, we identified this trouble layer yet again and saw that it was below 8” of partially settled snow.  It was still reactive in our pits with CT14’s Q2.  We noted that while it was still reactive and not going away any time soon, there wasn’t that big of a slab on top of it on this specific slope and we felt like we could manage it.

I skied first and enjoyed fine powder turns until about ¾ of the way down when I came to the steeper breakover that caused trouble for two skiers one week ago.  They had a similar episode as us and may have broken some of the same rules.  I pulled up and ski cut the breakover anticipating the small slab that I found. It broke 10’ above me and propagated 40’ wide.  After digging in and letting it go by, I recognized the hoar that here was buried 14”.  I stopped to take a closer look and snapped these next three photos. 

 

2010-02-23 UFO 1.jpg
General Comments 2
2010-02-23 UFO 2.jpg
General Comments 3




Because of the terrain, I was now out of sight with my partner and thought to myself that I should get moving because he didn’t know that I was still on the slope and also that I had triggered this slide. How many mistakes it this so far… Just then I was hit by a fast moving wall of snow that picked me up and cartwheeled me about 200’ before I came to rest mostly buried.  I had no chance to get out of the flow and stroked vigorously to stay close to the surface. I then got hit by another pulse of debris that moved me downhill a bit more and allowed me to swim closer to the surface.  When I finally stopped, I was facing downhill with only my head, right arm and tail of my right ski out of the snow.  I wiggled my right leg out and dug with my right hand to get the rest free.  I lost both poles, hat and glasses and later found the poles. 


2010-02-23 UFO 3.jpg
General Comments 4







The slide above me was about 100’ wide and 14” deep and was triggered on a 37° slope by my partner who was carried a short way before stopping in some trees.  It traveled at least 500’vert. before hitting me. 

I often struggle with how to manage terrain that makes you lose sight of your partners, but that combined with not great communication at the top, a couple of curious avalanche guys, disregarding obvious signs of instability, a bluebird day, alluring powder, and some pesky buried surface hoar, you get the recipe for an accident.  We should know better!

 

2010-02-23 UFO 4.jpg
Javascript is required to view this map.

Site Built by Dharmatech
Site Refresh by Flint Creative