Medicine Bow Nordic Ski Patrol
Patrol Log: Sunday, March 22, 1998: J. Hamann

 
22 March 1998, 8:30 am - 4:30 pm, Snowy Range.  Returned ER supplies (backboards, stiffnecks, webbing, etc.) to Snowy Range Ski Area before Sunday opening.  Skied from Green Rock onto Libby Creek Trail (snow stake at 51"), digging snowpits on S-SE and E-NE exposures (see data below).  Met several snowshoers and a few skiers on trail, advised of potential snow instabilities.  Returned to Green Rock for lunch and just in time to get out of the elements before a typical spring storm moved in from the west.  Observed the "emptying" of the woods (skiers, snowshoers, snowmobilers, one bicyclist) as the storm produced very wet conditions under strong winds.  Albany County Sheriff's Deputy 5-40 was patrolling this extent of Highway 130 in the morning and early afternoon, no SAR requests reported.  I moved down to the Snowy Range Ski Area at 2 pm to stay in out of the weather.  Helped out in Ski Patrol Aid Room and monitored FS radio until closing.
                        SNOWPIT DATA (Pit #1)
Observer:               Jerry Hamann
Date and Time:          10:30 am 22 March 1998
Location:               First overlook point on Libby Creek Loop Trail
                        SE Corner of SE1/4, NW1/4, Sec 24 T16N R79W
Elevation:              9900 feet
Surface Roughness:      Smooth, fresh, new, wet snow
Aspect:                 Southeast Facing (120 degrees), Open slope well below ridgeline
Incline:                25 degrees
Sky:                    Clear at start, cloudy at finish
Precipitation:          Very light, spitting snow at finish
Wind:                   Mild out of west
Total Snow Depth:       92cm
Ski penetration:        4cm
Foot penetration:       15cm
===============================================================================
H (cm)  R        F         D (mm)  W   Shovel    Comment          H (cm)  T (C)
===============================================================================
                                                                  Air     +10
 0                                                                  0      +1
       4F      Rounded   < 1      wet                              
 3.5
       1F      Rounded   < 1      wet            Hard crust
 9
       2F      Rounded   < 1      wet                              10      +1
14
      P-1F     Rounded   > 2      Ice/wet                         
20                                                                 20       0
      4F       Rounded   < 2      wet
26
      K-P      Solid Ice         
30                                                                 30       0
      2F       Scintered Rounded  wet
35
      K-P      Solid Ice
37
      P        Broken Ice
40                                                                 40       0
      F        Facets    > 3      wet Very easy shovel shear
52                                                                 50       0
      4F       Scintered RG >2    wet
63                                                                 60       0
      F        Facets    > 4      wet Easy shovel shear and RB     70       0
                                                                   80       0
92                                              Ground             90       0
==============================================================================
Comments on #1:  The snowpack on this slope has taken a heavy solar load, with the
pack "shrinking significantly" (I observed 194 cm of snow adjacent this pit one
month ago).  The pack from the surface to 40 cm down is a very cohesive, heavy block.
I was amazed by the stability results (many of my columns failed while attempting to
isolate them).  The hardened upper surfaces (ski penetration was minimal) are quite
deceptive, with significant instability deep down.  A skier or snowshoer might pass
across this slope with little hint of potential instability.  However, I suspect that
the weight of a snowmachine might be enough to produce some serious "whumpfing."
Melting around rock bands is also producing some treacherous air pockets which could
trap the unweary foot traveler.


                        SNOWPIT DATA (Pit #2)
Observer:               Jerry Hamann
Date and Time:          11:15 am 22 March 1998
Location:               Just above the Libby Creek Trail as it climbs to the
                        first overlook
                        NE Corner of SE1/4, NW1/4, Sec 24 T16N R79W
Elevation:              9750 feet
Surface Roughness:      Smooth, fresh, new, wet snow
Aspect:                 East-Northeast Facing (70 degrees), opening in treed slope
Incline:                25 degrees
Sky:                    Partly Cloudy
Precipitation:          Light, spitting snow
Wind:                   Light, swirling from south
Total Snow Depth:       165cm
Ski penetration:        5cm
Foot penetration:       20cm
===============================================================================
H (cm)  R        F         D (mm)  W   Shovel    Comment          H (cm)  T (C)
===============================================================================
                                                                  Air     +15
  0                                                                 0       0
       F       Rounded   < 1      wet                              
  3
       F       Dend., RG < 1      wet                              10       0
 15
      K-P      Ice                                                
 17
      2F       Scintered RG       dry                              20      -3
                                                                   30      -5
                                                                   40      -5
 42
      4F       Facets/Cols < 2    dry   Moderate Shovel Shear      50      -4
 57                                     Difficult RB Shear
      1-2F     Scintered RG       dry                              60      -4
 62
      2F       Facets/Some Scint. dry                              70      -4
 75
      1F       Scintered RG       dry                              80      -3
                                                                   90      -2
 95
      F        Facets   > 3       dry   Difficult Shovel Shear    100      -2
                                                                  110      -2
                                                                  120      -1
                                                                  130       0
                                                                   :        :
165                                              Ground           160       0
==============================================================================
Comments on #2:  This exposure was much more stable than the S-SE.  The rapidly
fluctuating air temperature was having a big impact on the conditions of the
surface snow (went from Swix Purple with good stick at 9:30 to beyond Asiago
Yellow by noon, back to icing conditions as the afternoon storm rolled in).

Summary:  the spring skier should watch snow stability conditions carefully,
remaining fully aware of the effects of aspect (sun loading, etc.) and temperature.
There might be a better slope choice just around the corner.

Parking Lot Counts at 8:45-9:20 am (stop at Snowy Range S.A.):
Lot              With Trailer    Without
VIS                   5             1
Barber Lake           0             0
Corner Mountain       1             0
Little Laramie        0             0
Sand Lake             0             0
Lower Green Rock      6             0
Green Rock           47            22  (74 and 25 at 2:00 pm)

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Page last modified March 23, 1998
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