Morning Wind Transport, Rock Creek Area

Submission Info
Thursday, April 20, 2017 - 9:15am
Red Flags: 
37° 28' 41.772" N, 118° 44' 40.344" W
Snowpit Observations
More detailed information about the snowpack: 

Skinned up Hilton moraine from the East Fork parking area in Rock Creek towards Patricia Peak. Stopped under Patricia due to active wind loading and poor ski conditions (stiff breakable wind crust), back down the same way. Noted blowing snow on Nevahbe Ridge on the way down to Rock Creek Rd (see photo).

0830 at 10000', E aspect on top of the moraine- Tair = -2 C, Tsurf = -5, Sky = few clouds, Wind = moderate from the W, Blowing snow = moderate blowing snow on Mt. Morgan S and Patricia Peak (see photo), Foot pen = 3cm. Snow surface: 1cm thick melt-freeze crust over 5cm of decomposing fragments atop another MFcr.

Snow transitioned from frozen melt-freeze crust to wind drifts and breakable wind crust at about 10300'. Some localized rolling snow. Active wind loading on Patricia Peak from W winds.

0915 at 10500', NE aspect in a wind deposit below Patricia Peak- Blowing snow visible all over Patricia. Wanted to see if recent wind slabs were still reactive. Mixed results on snowpack tests: CTV x2 down 7cm in fragmented crystals under a 5cm thick wind crust, CTM SC x2 down 26cm above a melt-freeze crust, CTH RP down 36cm in moist rounds under the MFcr. Did a PST to test the 26cm layer and 7cm layer: PST Arr 54/100 and 95/100 down 26cm, PST SF 15/100 down 7cm. Snow was dry and cold above the MFcr at 30cm down and moist and warm below it. (See PST photo).

Snow below 9800' on E aspects had softened to good corn by 0945.

1055 at 9700', E aspect at the top of the Hilton moraine- Tair = 4 C, Tsurf = -1, Sky = clear, Wind = light from the W, Blowing snow = light blowing snow on Mt. Morgan S, Foot pen = 10cm. Snow surface = corn.

Much less blowing snow on the drive back at 1100. Winds hadn't subsided all that much yet although they were definitely calming down a bit. Either most transportable snow had been blown by that point, or as temps warmed snow became heavier and harder to transport.

Snowpack photos: 
Blowing snow on Nevahbe Ridge 7am
Blowing snow on Mt. Morgan S 730am
PST under Patricia Peak
Weather Observations
Blowing Snow: 
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More detailed information about the weather: 
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