Avalanche Forecast
Regions: Olympics.
Cooling should reduce the potential for wet slab and wet loose avalanches through the day on Friday. Use caution on steeper and unsupported terrain, especially in areas lacking a strong near-surface crust.
Detailed Forecast
Continued cooling with light snow showers are expected overnight Thursday and early Friday. Friday should remain mostly cloudy with a chance of a few light showers.
This weather will help to decrease the avalanche danger by allowing a surface crust to form and remaining liquid water to drain. However, the recent heavy rains may have left liquid water in the upper snowpack, making wet snow avalanches still possible Friday. Â
Wet slab avalanches are hard to predict and potentially powerful due to the high water content within the slab. The wet slab potential is decreasing through Friday, but extra caution is advised, especially on steeper and unsupported terrain, especially in areas lacking a strong near-surface crust.
The forming near surface crust should help the stabilization process by Friday, but warming afternoon temperatures may weaken or melt surface snow. Watch for areas where the crust is breaking down or where wet snow is becoming more than a few inches deep.Â
Snowpack Discussion
Weather and Snowpack
A rain event beginning last Wednesday 2/8, left a strong rain crust with varying amounts, up to about 8 inches of new snow accumulating at Hurricane, by Saturday 2/11. Strong west winds, exposed a firm and slick crust on windward aspects in many areas. Â
High pressure last Saturday to Tuesday brought increasing sunshine and warm temperatures. Temperatures reached the 40's and 50's in many areas of the Olympics and Cascades by Monday and Tuesday. This caused about 8 inches of snowpack settlement at Hurricane Ridge. Â
Another atmospheric river impacted the PNW beginning Tuesday night. Heavy precipitation at high snow levels fell throughout the Olympics and west slopes of the Cascades. Hurricane Ridge received over 2.5 inches of rain by Thursday morning.
A slow cooling trend began overnight with only light showers with little to no new snow accumulations at Hurricane Ridge by Thursday evening.
The wet snowpack is beginning to drain and slowly refreeze as of Thursday evening.Â
Recent Observations
No recent observations.Â
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.
Elevations: Below Treeline.
Likelihood: Possible
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.
Elevations: Treeline, Below Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1