Avalanche Forecast

Moderate

On Thursday, there were several large (up to size 2) natural avalanches in the steep terrain on the N face of Mt MacDonald. These were triggered by the extreme SW winds (up to 125km/hr!)

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 dive as northern air moves in to our area.

Tonight Clear periods. Alpine low -18°C. Ridge winds 15-25km/h from the NE.

Sat Mostly sunny. Alpine temp steady near -16°C. Light west wind.

Sun Mix of sun and cloud. Alp low -17°C, high -15°C. Light East wind.

Mon Mix of sun and cloud. Alpine high -12°C. Light west wind. Alpine temp inversion.

• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
• Be especially cautious as you transition into wind-affected terrain.