We have yet to see if/where Thursdays storm may have tipped the scales, making previously buried surface hoar reactive to skiers and riders.
Ease your way into terrain, as you assess the effect this wind event has had on the upper snowpack.
Extreme winds, warm temps and light snowfall has built fresh windslabs. Expect wind effect to be lower on the slopes, and further in to sheltered terrain than usual.
Up to 50cm of new snow this week is settling into a slab and sits on a persistent weak layer from January 7th. This weak layer has been found in profiles both at treeline and in the alpine.
On Thursday, there were several large (up to size 2) natural avalanches in the steep terrain on the N face of Mt MacDonald.
On Monday, a skier triggered a size 3 avalanche in Lone Pine. This ran ~1000m and accumulated significant mass.
Up to 10 cm of new snow came in with Extreme SW winds on Thursday. Expect wind effect to be lower on slopes than usual, and potentially into typically sheltered terrain.
30-40cm down, there is a weak interface (Jan 7th layer) of surface hoar into the high alpine, and a thin crust on steep S aspects. Where the upper snowpack has stiffened into a slab, this layer could be triggered by the weight of a skier.
Overall the mid and lower snowpack is strong and well settled.
Temperatures plummet, as arctic air moves in to our area.
Tonight Clear periods. Alpine low -16°C. Gusty moderate-strong Northwest ridgetop winds.
Fri Sun/cloud/isolated flurries. Alpine high -15°C. Moderate gusty North wind.
Sat Mostly sunny. Alpine low -19°C, high -18°C. Light East wind.
Sun Sunny. Alp low -18°C, high -13°C. Light East wind.
