Avalanche Forecast
Regions: Olympics.
Loose wet avalanches and possible wet slab avalanches in the above tree line should be the main avalanche problems on Saturday.
Detailed Forecast
The ridge will slightly amplify and gradually shove the incoming warm front moisture north to BC on Saturday. So rain will initially decrease in the south Cascades Saturday morning and then in the Olympics and north Cascades Saturday afternoon and night with high snow levels and very mild temperatures.
Loose wet avalanches should still be likely mainly in the above tree line where there is significant snow coverage on Saturday. Avoid steep slopes if you are in significant rain and start to see wet snow deeper than a few inches or increasing natural pinwheels or rollerballs.
The possibility of wet slab avalanches on Saturday should be just in the above treeline where there is significant snow coverage while there is still significant rain Saturday morning.
The avalanche danger should be lower by later Saturday but it is difficult to say how much due to the rapidly changing conditions.
Snowpack Discussion
Snow on the back end of the last storm Sunday and Monday was about 7 inches at Hurricane.
NWAC pro-observer Katy Reid was at Hurricane on Sunday. She mainly reported poor coverage and shallow new snow well bonded to previous melt form snow. She also reported stable melt form layers in the mid and base pack where it existed. Here is her video from Sunday on our YouTube Channel.
Warm front moisture from the sub tropics will move over an upper ridge and mainly over the Olympics and Washington Cascades through Friday night. This will bring rain and greatly rising snow levels Friday and Friday night. This will give the snowpack a good test in most areas and we should find out if there much of an avalanche cycle from reports on Saturday.
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: Alpine, Treeline.
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 - 1