Avalanche Forecast
Regions: Cascades - North West.
Avoid avalanche terrain at upper elevations and where slopes are steeper than 30 degrees. Use extra caution if traveling in areas where avalanches may run or stop. Very large and destructive wet avalanches and cornice falls are possible where heavy rain is falling on a previously dry snowpack.
Detailed Forecast
Expect dangerous and complex avalanche conditions today due to heavy rain and warming temperatures. Wet avalanches can be very large and can pose serious consequences. Avalanches big enough to bury a car are not out of the question today. The most dangerous slopes are near and above treeline, where previously dry snow will become saturated with water for the first time. Avoid slopes with a wet snowpack that are 30Â degrees and steeper.
Wet Slab avalanches hold today’s gravest consequences. These avalanches are difficult to anticipate and manage. Use extra caution when crossing the tracks and runouts of avalanche paths and where you are exposed to overhead avalanche terrain. Wet Slabs could start at upper elevations and run long distances into lower elevations.
 You are most likely to trigger or see Wet Loose avalanches. Many of these slides ran in the past couple days. While these avalanches may be the most predictable of today’s problems, they could still be forceful or large enough to injure or bury you. Avoid traveling through or above terrain such as or cliffs, gullies, or rocky slopes where the consequences of being caught in an avalanche could be increased.
Cornice fall and Glide avalanches have become possible due to rain and rising temperatures. Both could be very large and dangerous. Avoid areas with visible glide cracks or where known rock slabs underlie the seasons snowpack. Give yourself an extra wide margin of safety near ridges that could hold cornices, and avoid slopes with cornices overhead.
Snowpack Discussion
Mild wet weather changed snow surface conditions in the Mt Baker backcountry Friday and Saturday. Below 5000 feet, warm temperatures and rain created moist to wet avalanche conditions. This was highlighted by a natural Loose Wet avalanche cycle on all aspects and some cornice fall.
Above 5000 feet, a few large natural Wet Slab and Wind Slab avalanches occurred during peak warming and precipitation Friday. These elevations will receive close to 2 inches of rain on Sunday, and have the potential to produce very large wet avalanches
Across the area 2-3 feet of settled storm snow accumulated over the past week.
Observations
Mt Baker Ski Patrol reported rain to 5000 feet Friday and Saturday with a natural loose wet avalanche cycle occurring in the adjacent backcountry terrain. They observed debris from larger slab avalanches on the Shuksan Arm and Mt Herman as well as cornice fall near Table Mountain.
NWAC Forecaster, Dallas Glass, was greeting backcountry travelers at the Heather Meadows trail head on Saturday and reported snow lines waivering between Heather Meadows (4,200ft) and ridge tops. Dallas observed numerous wet loose avalanches in the Bagley Lakes area.
NWAC pro-observer Lee Lazzara traveled in the Canyon Creek area Thursday. Lee found 15-24 inches of recent snow over the 1/29 crust. Wind Slabs were noted in terrain near ridgeline but poor visibility limited observations near treeline.
Avalanche Problems
Loose Wet
Release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.
Several loose wet avalanches, and lots of pinwheels and roller balls.
Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1
Wet Slabs
Release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slab avalanches can be very destructive.
Avoid terrain where and when you suspect Wet Slab avalanche activity. Give yourself a wide safety buffer to handle the uncertainty
A Wet Slab avalanche. In this avalanche, the meltwater pooled above a dusty layer of snow. Note all the smaller wet loose avalanches to either side.
Wet slabs occur when there is liquid water in the snowpack, and can release during the first few days of a warming period. Travel early in the day and avoiding avalanche paths when you see pinwheels, roller balls, loose wet avalanches, and during rain-on-snow events.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind lips of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
Cornices can never be trusted and avoiding them is necessary for safe backcountry travel. Stay well back from ridgeline areas with cornices. They often overhang the ridge edge can be triggered remotely. Avoid areas underneath cornices. Even small Cornice Fall can trigger a larger avalanche and large Cornice Fall can easily crush a human. Periods of significant temperature warm-up are times to be particularly aware.
A corniced ridgeline. A large cornice has formed at the top of the ridge. A smaller cornice has formed to the left of the trees from crossloading.
Cornices are easy to identify and are confined to lee and cross-loaded ridges, sub-ridges, and sharp convexities. They are easiest to trigger during periods of rapid growth (new snow and wind), rapid warming, and during rain-on-snow events. Cornices often catch people by surprise when they break farther back onto flatter areas than expected.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2