Avalanche Forecast

A band of enhanced snow showers should arrive Friday night with diminishing showers Saturday. This should freshen storm snow and combined with moderate winds, continue to redistribute snow and build unstable slabs on a variety of slopes by Saturday. This weather should cause widely variable snow conditions with some wind exposed slopes scoured to recent crusts and lee slopes building deeper wind drifts and slabs. Watch for changes in snow conditions, particularly stiffer more dense snow, likely a wind or storm slab. Avoid travel on slopes if you encounter wind stiffened surface snow, especially on steeper exposed terrain and steep roll-overs.    

Wind slabs near and above treeline remain the primary avalanche problem in this area, so remain conservative in your terrain choices especially as you venture into exposed terrain.

The best and safest snow will remain in sheltered terrain away from ridges. 

Cascade West-North above treeline terrain will have very dangerous avalanche conditions continuing Saturday with large and potentially deadly wind slabs. Travel in this area should be avoided until well after these slabs have time to stabilize. 

 

In the Mt Baker area, nearly 3 inches of water equivalent has fallen since Wednesday evening! Heavy rain quickly changed to snow and much of the precipitation has fallen as snow at gradually cooling temperatures. Winds have ranged in the 20-50 mph range much of that time.

As of Friday afternoon there was already about 2 feet of storm snow below treeline with much deeper storm snow near and above treeline.

The winds have been actively re-distributing the new snow and creating a highly variable surface snow conditions.

The combination of heavy snowfall and strong winds have made very dangerous avalanche conditions above treeline where deep wind slabs have formed.

Near and below treeline the precipitation began as rain and transitioned to snow helping form a good bond at the interface. The forming crust is still soft and breakable, now insulated by 2 feet or more of storm snow.The strong winds, even at mid and some lower elevations are re-distributing new snow and forming increasingly thick slab deposits on a variety of aspects. 

The old rain wet snow continues to gradually re-freeze and form a new crust layer.

The older snowpack has undergone several rain or warm periods and remains void of any significant layers of concern but still contains significant recent water in the snowpack..

Observations

North

On Friday, professionals for NWAC traveled to near treeline and avoided higher exposed terrain above treeline due to potential for large and dangerous wind slabs. Takeaway was the active wind transport and new snow happening throughout the day as well as evidence of significant recent wind re-distribution of the deep storm snow. Most slabs encountered were shallow, soft slabs formed from wind loading. There was evidence of a large wind slab release above treeline on a north aspect with a depth roughly estimated at 3 ft or more.   Up to treeline there was about 2-3 ft of storm snow over the forming Jan 16 rain crust.

Thursday morning, the Mt Baker Pro Patrol reported fresh wind slabs were sensitive to ski cuts and were releasing in the 4-5 inch range, near treeline. Winds were reportedly very strong along ridges and actively transporting the new snow. 

Central

NWAC forecaster, Dallas Glass was on Skyline Ridge at Stevens Pass Thursday and reported new storm snow of 8 inches at 4000 feet and 14 inches above 5000 feet. The bonding was good to the old rain wet snow. The crust had yet to re-freeze but was in the process. There was evidence of recent wind transport with a fresh natural avalanche having released on a steep east face about 5300 feet, likely during a brief warm up Wednesday night. There were storm slab layers noted from fluctuating temperatures overnight, but were not sensitive to human trigger in that location. 

South

No recent observations