Observation: Big Springs

Observation Date
01/5/2016
Observer Name
Brett Kobernik

Region:

Location Name or Route
South Fork of Big Springs
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
South
Wind Speed
Light
Weather Comments
A few moderate speed gusts in the afternoon in the higher terrain.
Snow Characteristics
New Snow Depth
2"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments

A few inches of newer snow over a spongy base provided nice riding.  Upper elevations have seen more wind damage along the ridges especially the more easterly facing slopes.

Red Flags
Red Flags
Rapid Warming
Red Flags Comments
A little warm at the lower elevations but it didn't seem like enough to get real excited. UDOT Provo did report some wet loose slides that made some small debris piles on the north fork road.
Avalanche Problem #1
Type
Wind Slab
Trend
Decreasing Danger
Problem #1 Comments

Seems like the most likely type of avalanche a person will trigger here is a newer wind slab.  It seems like these are most pronounced on the west through north aspects due to the easterly winds of late.  These can be a bit hard to spot as they are now covered with a few inches of new snow.  They'll become more stubborn but I'd watch them in the steeper terrain.

Avalanche Problem #2
Type
Deep Slab
Trend
Decreasing Danger
Problem #2 Comments

In the deeper areas (>4' HS) it seem like the Deep Slab problem is on it's way out.  Basal facets are looking much better at this point.  Shallower areas still hold quite weak snow near the ground.  In areas with less than 3 feet overall depth, my boot would penetrate through the slab into the weak snow near the ground.  Although there is weak snow still present in these areas, it seems like they are trending to the dormant stage for the time being.

Snow Profile
Aspect
Northeast
Elevation
8500
Slope Angle
30
Comments

Wow!  Another day of viewing massive avalanches that ran during the Xmas cycle.  Pretty much the entire upper end of the south fork of Big Springs released.  This included west, north and east aspects with crowns at various elevations.  Here are some photos in the Big Springs Avalanche Report.

We could see other crowns all over Big Springs but we were not up close to confirm that the rest of Big Springs avalanched like the south fork did.  My best guess is that the rest of Big Springs avalanched just like the south fork did.

We were able to find an area to do a snowpit profile where the entire season's snowpack remains in place.  (not many places like that up there!)  I thought it looked pretty good with the weak faceted snow near the ground no doubt increasing in hand hardness indicating it is indeed strengthening.  The snowprofile was produced with the new Avatech SP2 electronic snowprofile probe.  We also dug here to confirm the profile from the device.  It matched up quite well to our manual findings.  The mid December rain crust is very evident in the profile although there is no monkey business going on around it.

We got up into one of the west facing starting zones which avalanched.  The bed surface has about 12 to 18" of new snow on it.  The structure at this location looked ok with most of the faceted snow washed out by the avalanche.  There were a few places in the track where there were some loose facets left.  These paths that ran will need to be monitored closely as time goes on.  If we go into a long period of high pressure, they could again become weak under the near surface faceting process.  In the short term, I would also be careful of any recent wind loading that may have loaded these up.

Below, Avatech SP2 snowprofile in the starting zone.

The bottom line is things in the Provo region are looking better but it's not 'anything goes'.  Stability analysis is tricky even for very seasoned backcountry travelers.  Below, shot of a recent little wind pocket that failed but didn't move much.  Westerly facing.

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Snow Profile Coordinates