New Snow and Blowing Snow On Tamarack Peak

Driving up to Mt. Rose snow level seemed to be hovering around 7500 ft this morning. The storm intensified around 9 am as we left the parking lot. We noticed snowfall rates increasing and visibility decreasing. Once we gained the ridge, signs of wind-loading were easy to spot. Active blowing snow, new cornices above wind-loaded slopes, wind scouring on the leeward slopes, and ripples and other wind textures on the snow surface. We found several wind-loaded test slopes and could cause some cracking in some of them by 11:30 am. On the most wind-loaded test slopes, we found new wind slabs forming on top of old wind slabs on top of old weak surface snow (near surface facets). When we undercut these test slopes, skier triggered cracks would propagate up to 15 ft and the stack of wind slabs would slide on the old weak surface snow about 1 foot below the surface. A few days ago these old slabs were not as sensitive. We took this data to mean that the new loading could be making the old and new wind slabs more fragile. We chose to avoid wind-loaded slopes and found better visibility and snow conditions on tree-sheltered slopes. While returning to the car, we looked for sheltered test slopes to see how the new snow was bonding to old snow surfaces in sheltered areas. The bonds between new and old snow appeared weak but the new snow did not have any slab characteristics in these more sheltered areas. By the time we returned to the car 3 to 4 inches of new snow had accumulated during our 3.5-hour tour.  Driving home snow level seemed to have dropped to around 7000 ft. 

Photo 1: Stormy conditions at Tamarack. 

Photo 2: Skier triggered crack on a small wind loaded test slope.

Photo 3: New wind slab on top of older hard wind slab on top of old weak surface snow on that same test slope.

Photo 4: 3 inches of snow on the hood of the truck after we returned from the tour.