Early season conditions update #2 - Regular avalanche advisories will begin later this fall.
Another storm system is expected to impact the forecast area Wednesday night and Thursday. Anyone participating in over snow travel in or near avalanche terrain needs to carry and properly use companion rescue gear a well as apply avalanche avoidance training. Mellow touring on snow covered forest roads is the best bet for on snow recreation at his time.
The upcoming Wednesday night/Thursday storm is expected to have fairly high snow levels. Rain on recent new snow may create some loose wet avalanches. This will generally be limited to locations above 7,000' that received several inches or more of new snow during the Nov 3 -4 storm event.
Strong to gale force S to SW ridgetop winds combined with new snow Wednesday night/Thursday will allow for the possibility of another round of wind slab formation. This is expected to be limited to areas above 8,000' given the current snow level forecast of 7,500' to 8,000'. New wind slabs are expected to be 1 foot thick or less. The most problematic wind slabs are expected in areas where ground level anchors are covered by either new snow from the Nov 3 -4 storm event or by patches of old snow left over from last winter.
The Nov 3 - 4 storm event deposited little to no new snow in some locations while 12 to 16 inches of new snow deposited above 7,000' in other portions of the forecast area. The greatest accumulations occurred above 7,000' along the Sierra Crest from the northern boundary of the forecast area down to somewhere in between Ellis Peak and Rubicon Peak. New snow amounts were dramatically less in the southern and eastern portions of the forecast area where many locations picked up just 3 inches above 7,000'. This new snow was deposited on bare ground in most areas. A few leftover snow patches from last winter exist in isolated areas on upper elevation northerly aspects.
In those areas that received a foot or more of new snow Nov 3 - 4, southerly aspects have undergone melt-freeze and northerly aspects have become wind affected while escaping melt. On the northerly aspects, the snowpack is showing increasing amounts of stratigraphy with thin surface wind slabs on top of less dense recent new snow in near and above treeline areas.
