Recent snowfall, strong westerly winds and a snowpack with poor structure have conspired to create dangerous avalanche conditions. Backcountry riders and skiers could trigger wind slabs in steep, wind-loaded terrain. Deep persistent slabs, which lie upon faceted snow, also remain a concern. These slabs could be triggered directly by backcountry travelers or step down from surface slabs. Cautious route finding and conservative decision making is essential today.
Strong west to northwest winds have formed soft wind slabs on leeward slopes at all elevations. These slabs could be triggered with depths up to 18 inches. These slabs are most likely to be encountered in exposed terrain near ridgelines where the most heavy wind loading has occurred. Failure of these wind slabs could step down to deeper weaknesses in the snowpack.
Weak layers of faceted snow persist deep within the snowpack. Failure of these layers will produce very large avalanches with depths up to six feet. The consequences of being caught would most likely be fatal.
( Discussion is generated from the previous day's afternoon forecast. )Snowfall is expected to return to the area after midnight and continue into Tuesday. Accumulations of five to ten inches are possible by the evening. Overnight lows in the mountains will be in the mid to upper teens before rising into the mid 20s during the day. Valley temperatures will dip into the mid 20s tonight before rising to near 40 in the afternoon. Westerly to northwesterly ridgetop winds will range from 20 to 30 miles per hour.The general avalanche hazard is expected to be CONSIDERABLE on Tuesday. In exposed terrain, backcountry travelers could trigger these slabs to depths up to 30 inches deep on steep, wind-loaded slopes. These slabs could step down to deep, persistent weak layers of faceted snow producing very dangerous slides up to six feet deep. Shallow pockets of new wind slab will slowly build as the day progresses. At the lower elevations, skiers and riders could trigger pockets of slab up to a foot deep in steep terrain if temperatures remain above freezing overnight, particularly if rain occurs during the day.
