Around a foot of new snow has fallen since yesterday afternoon and more is in the forecast for today. Strong westerly ridgetop winds has accompanied this snowfall and formed new, soft winds slabs in leeward terrain. This rapid loading event has also added weight to existing persistent slabs. Above 7,500 feet, very dangerous avalanche conditions exist, and TRAVEL IN AVALANCHE TERRAIN IS NOT RECOMMEDED. Below 7,500 feet, use cautious route finding and avoid any terrain beneath higher avalanche paths.
Winds slabs have formed on slick sun crusts in sunlit terrain. On shaded slopes, they are building upon surface hoar and loose snow. These slabs, with depth of one to two feet, will be very sensitive to human triggers and could release naturally. As additional snowfall accumulates, these slabs will increase in depth and become more susceptible to failure.
Additional weight from the new snowfall has increased the likelihood of triggering persistent slab avalanches. These slides, which could be up to four feet deep, could be triggered by skiers and riders or step down from the release of a new wind slab. This threat will also increase during the day with continued loading.
( Discussion is generated from the previous day's afternoon forecast. )A Winter Storm Warning is in effect for the area this afternoon through 5pm Saturday. Snow that will be heavy at times is to continue Saturday afternoon. Southwest winds with 20-30 mph averages will cause blowing and drifting snow. Over a foot is expected in the mountains by Saturday night. Temperatures are to be cooler with highs in the teens. The general avalanche hazard is expected to be rated as Considerable in the early morning hours above 7500 and may increase to High depending on the timing and amount of new snow and wind. New wind slabs will be very sensitive to human triggers and may release naturally. These slabs will increase in size and sensitivity during the day as they are further loaded. Although unlikely, this rapid loading could cause failure of deeper layers in the snowpack to depths of four feet. Below 7500, the hazard will increase at least to Moderate as new storm slabs form over existing snow surfaces.
