We will see a return to spring-like temperatures around the Sierra Mountains early this week. Intense solar radiation in the afternoon will melt the new surface snow, making it more suseptable to human triggering on slopes steeper than 35 degrees. Adjust your riding plans when you notice a glazing & lustrious appearance to the snow surface & when your track begins to sink more than usual.
Most of the avalanches that have been seen are the result of naturally occurung cornice falls. Another product of afternoon solar radiation & temperature increase is that cornices will become deformed & slowly creep untill the bonds that hold it together reach the point of collapse. Dripping & small chunks of cornice falling mid-day are good indicators of cornice instability.
The new snow that fell on Friday & Saturday still needs time to sinter to the old melt-freeze crust that exists below it. Strong winds have scattered the precipitation to loading zones on aspects from South through Northeast. Winds have elongated this slab, in areas with substantial fetch, lower on the slope than is normally expected.
The 50cm that fell at the end of last week was wind effected. The new snow sits atop an older melt-freeze crust which through stability testing has proven to be the interface of concern. A moderate to hard force was allowing this slab to propigate, in planar fracture, the uppermost & unstable new snow surface.
Rapid mid-day warming will change the stability of the surface snow making it loose & easily triggered. Mild evenings will exacerbate this thawing process.
This snowpack summary applies only to backcountry areas in the Bridgeport Winter Recreation Area. Click here for a map of the area. This snowpack summary describes general avalanche conditions and local variations always occur. This snowpack summary expires in 48 hours unless otherwise noted. The information in this snowpack summary is provided by the USDA Forest Service who is solely responsible for its content.
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