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Observation: Silver Fork

Observation Date
2/28/2017
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » Silver Fork
Location Name or Route
Figure 8, Twin Lakes Pass, East Bowl, Flanigans
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Skies remained obscured for the majority of the day with a small break of scattered at 1500. Sporadic snow showers with accumlations for the day hitting only 2 inches at the most. Winds were vacilating between moderate and strong on the upper ridgelines, and transport/wind blown was moderate with active loading on easterly aspects. Mountain topography was definitely channeling the winds in many locations and there were times in the upper reaches of Silverfork when the winds appeared to be more WSW. Mid elevation and protected upper elevation terrain was not getting adversely affected by the winds. Temperatures remained in the single digits.
Snow Characteristics
New Snow Depth
3"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments

New snow in the past 24 hours appears to be 3 inches. Trail breaking in the upper elevation windy areas was challenging with drifting up to 3 feet in areas. Otherwise the new snow has settled significantly and ski penetration in undisturbed/non winded snow was 25 cm. The last round of snow was extremely light density and the riding was excellent in right side up snow.

Red Flags
Red Flags
Wind Loading
Cracking
Red Flags Comments
Minimal cracking was observed in the areas that had received even modest wind loading. Other areas with thicker wind slabs were cracking and mostly stubborn, though no efforts were made to investigate steep wind loaded terrain. The winds and light snow were sending plumes and loading upper elevation terrain ranging from NE to SE aspects.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments

See above, and it appeared that there was definite areas receiving enough loading that there may have been natural wind slabs in very steep NE through SE upper elevation terrain. At 1700 at 8000 feet in BCC the winds appear to be ramping up and more gusty than earlier in the day. Winds in the upper elevation terrain were sustained in the high end of the moderate category with occasional gusts into the strong range. Hence, this problem appeared to be the main issue of concern for the day. Forecasts for the evening appear to indicate more of these velocities and gusty winds.

Avalanche Problem #2
Problem
New Snow
Problem #2 Comments

Loose dry avalanches were easy to trigger with slope cuts and cornice drops on steep slopes. These sluffs were running in the top 15 to 18 cm of snow. On sustained steep slopes these sluffs were entraining significant amounts of snow.

Cornice appear to be locking up on their lower sections with these cold temps. The only releases were occuring in the newly loaded snow on them.

Afternoon forecast for Wednesday appears to be offering sunny skies and if this validates, Wet Loose Avalanches may be possible on SSW, SW and W aspects.

Todays danger appeared to Moderate on the majority of the terrain. There was a very isolated likelihood of natural wind slabs in very steep upper elevation wind loaded terrain facing NE, E and SE

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate