Very dangerous avalanche conditions exist. Unstable wind slabs have formed on a variety of weak snow layers including crusts, faceted snow and surface hoar. These slabs could release naturally today as temperatures continue to rise and they are further loaded by the predicted heavy snowfall and very strong winds. Possible rain at low elevations could cause low elevation slides that impact roadways as well as roof slides. Travel in avalanche terrain is not recommended.
Soft to hard slabs could be triggered on all elevations and aspects today. These slabs will increase in size and sensitivity and could have depths three feet at the higher elevations this afternoon and to one foot at the lower elevations.
A slight chance continues for snowmobilers to trigger very large deep slab avalanches in isolated areas on northerly aspects above an elevation of 9,000 feet. If triggered, these dangerous hard slabs could involve the full depth of the snowpack.
( Discussion is generated from the previous day's afternoon forecast. )The new snowfall that has already begun is the beginning of a strong upstream disturbance that will deposit significant snowfall through Saturday. The National Weather Service has issued a Winter Storm Warning through 11 pm. Fourteen to twenty inches of snow is expected in the higher country during this period. Winds will veer from the south to the southwest and have averages between thirty and thirty five miles per hour. Mountain temperatures are to rise from the teens in the morning to the mid twenties during the afternoon.The avalanche hazard will be Considerable in the early morning and if forecast snowfall amounts and wind speeds occur, will increase to High during the day. Very sensitive wind slabs lie on a variety of aspects and all elevations. These slabs will increase in both size and sensitivity as the storm continues to load them throughout the day. They are forming on hard snow surfaces in high exposed terrain and faceted snow and surface hoar in all other terrain. Human triggered slides are likely and the possibility of natural avalanche activity will increase throughout the day. In the Togwotee and Southwest trails areas, the chance for deep hard slabs continues on northerly aspects.
