Isolated Wind Slabs and Small Loose Wet Avalanches on Gaylor Peak

SNOWPACK OBSERVATION
Submission Info
Forecaster
Wednesday, April 18, 2018 - 12:00pm
Red Flags: 
37° 55' 8.4" N, 119° 15' 55.8" W
Snowpit Observations
More detailed information about the snowpack: 

Toured from the NE bowl of Gaylor Peak near the Nunatak S along the ridge popping off to look at the W and E sides and skied down the E facing bowl above the Tioga Pass entrance station. Elevations observed: 9600'-11,000'. Aspects observed: NE-E-SE-S, some W. Times observed: 945am-115pm. A variety of snow surfaces ranging from F hard DFs on top of hard previous wind deposits on N and NE aspects to 30cm deep 4F hard wind slabs on top of 1F hard melt-freeze crusts on E facing ridgelines to moist melt-forms on top of supportable melt-freeze crusts on E-SE aspects. Many hand shears on NE-E aspects failed with easily under thin wind deposits within the soft dry storm snow underneath and above the 4/11 melt-freeze layer (see hand shear photo). The E side of Gaylor ridge had areas of significant wind loading from the past two days. These areas had large fetches on the W side of the ridge and still had cornices and wind slabs that were reactive in ski cuts and cornice drops (see wind slab test slope photo). Newer wind slabs along portions of the ridge were up to 30cm thick and 4F hard. They failed in F hard DFs under the slabs. Failures were small because the slope angle flattens out quickly, but I would expect similar aspect and elevation slopes to have the potential for up to D2 skier triggered wind slabs still today. S and E aspects (E aspects after 1230pm) where already transitioned to melt-freeze spring snow. Some test slopes had medium sized rollerballs. I triggered some D1 loose wet slides on E aspects of about 35 degrees or steeper around 1pm. These failed within the top 1" of wet snow and slid on a supportable melt-freeze crust (see loose wet video). General impression: Wind slabs were isolated but occasionally reactive to skier trigger above about 10,500' on N-NE-E aspects today. Loose wet avalanches were touchy below about 10,500' on NE-E-SE-S aspects after about 1230pm.

Snowpack photos: 
Small results in 30cm thick wind slabs on a NE aspect at 11,000'
Hand shears failing with easy force under 4F hard thin wind slabs on N and E aspects above 10,500'
Increasing moisture with a cutoff low moving in from the W
Coverage of S and SW aspects looking N from the summit of Gaylor
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

High thin clouds today and increasing moisture with the incoming cutoff low coming from the SW. Winds at ridge tops were moderate with strong gusts from the SW throughout the day. Some light blowing snow. Clouds actually diminished to broken by mid day for a period which allowed more warming of E and NE aspects.

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