Virginia Lakes

Toured up to the top of the saddle between Mt. Olsen and South Peak in the Virginia Lakes Basin to check sensitivity of old wind slabs and see snowpack faceting and depths prior to the (hopefully) upcoming weather pattern change. Almost every snow surface on northerly aspects was wind affected with a few areas of soft surface facets in sheltered trees (see N aspect photo). The snowpack is generally shallow except for the deepest wind drifts. HS ranged from 30 to 65cm with a few drifts up to 1.5m in the middle of gullies. Hand shears pulled with moderate force under wind deposited layers on top of F hard facets down 5 to 30cm. Test slopes had no results. Two sets of compression tests on NE and NW aspects between 10,000' and 10,300': CTM BRK on well developed facets on the ground, CTM BRK on facets down 19cm, CTH BRK again just above the ground, CTE BRK at a density change in large facets 12cm above the ground, and CTM BRK at the same interface.

The take away from all of this is that while there's not a lot going on at middle and upper elevations right now these shallow, weak, sugary layers in the snowpack will most likely present a difficult to predict avalanche problem once they are buried. And it is noteworthy that these conditions are not of the kind we are all used to here in the Sierra. See attached profile.

South facing aspects had developed melt-freeze crusts and moist poly crystals (early stage corn) even above 10,700' where snow exists. Most sun-exposed slopes are bare of snow (see S aspect photo).