West Slopes North
Backcountry Avalanche Forecast
Author: Lee Lazzara
Issued: Friday, April 17, 2026 at 6:30 PM PDT
Expires: Saturday, April 18, 2026 at 6:30 PM PDT
The Bottom Line
The Bottom LineWarm temperatures and sun will continue through the weekend. Wet snow and wet loose avalanches are now possible on all aspects, including northerly terrain. Cornice fall and glide avalanches could become a concern with prolonged warming—keep track of what is above you as the day warms.
Avalanche Danger
Saturday, April 18, 2026
7500-5500ft2 - Moderate
5500-4500ft2 - Moderate
4500-2500ft2 - Moderate
Sunday, April 19, 2026
7500-5500ft3 - Considerable
5500-4500ft3 - Considerable
4500-2500ft2 - Moderate
Avalanche Danger ScaleLearn moreGeneral InfoGeneral Information1 - LowLow2 - ModModerate3 - ConsConsiderable4 - HighHigh5 - ExtrExtreme
 1 - Low | 2 - Moderate | 3 - Considerable |  4 - High |  5 - Extreme | |
|---|---|---|---|---|---|
| Travel Advice | Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. | Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. | Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential. | Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. | Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain. |
| Likelihood of Avalanches | Natural and human-triggered avalanches unlikely. | Natural avalanches unlikely; human-triggered avalanches possible. | Natural avalanches possible; human-triggered avalanches likely. | Natural avalanches likely; human-triggered avalanches very likely. | Natural and human-triggered avalanches certain. |
| Avalanche Size and Distribution | Small avalanches in isolated areas or extreme terrain. | Small avalanches in specific areas; or large avalanches in isolated areas. | Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. | Large avalanches in many areas; or very large avalanches in specific areas. | Very large avalanches in many areas. |
Avalanche Problems (2)
Problem #1: Wet Loose
Problem Type
Wet Loose
Aspect/Elevation
Likelihood
Size
(3/27/2026)
This wet loose avalanche is not very big, but it's still bigger than the dots on the skin track.
Photo: Robert Shughart
Dry snow is slowly disappearing from northerly aspects as warming continues and mid-April sun reaches previously shaded terrain. Ongoing warming also brings back the low-likelihood, high-consequence hazard from glide avalanches and falling cornices.
Variability in temperature, cloud cover, and upper snowpack layering means variable conditions across the forecast zone—don’t expect a set number or size of wet avalanches. As usual, larger avalanches remain possible on long fall-line slopes and in big alpine terrain.
Avoid steep slopes where you see fresh rollerballs and small wet avalanches, or where the snow is mushy and wet. Be cautious when committing to terrain with steep, sun-exposed exits or overhead hazards. If it’s warmer than expected, adjust early—before your options shrink.
Problem #2: Wind Slab
Problem Type
Wind Slab
Aspect/Elevation
Likelihood
Size
(4/16/2026)
Ripples of lightly wind-affected snow on Mt. Ann.
Photo: Wesley Loechelt
There have been some signs of wind-affected snow, but wind slabs haven’t been widespread in the main portions of the forecast zone. Chances are it’s a different story in high alpine terrain or farther east near North Cascades NP. Look for signs of previous wind transport like fresh cornices, scoured snow, and changes in surface texture or stiffness. Most wind slabs should be small, but even a small slab could have high consequences in steep alpine terrain.
Forecast Discussion
The last avalanche forecast for the 25-26 season will be for Sunday, April 19th. Mountain weather forecasts will be published each afternoon through May 3rd. A huge thanks to everyone in our community for your support this winter!
The snow from this week’s storm has generally been well behaved, with human-triggered slab avalanches limited to slopes over 40 degrees, and most were small. The one outlier was a large human-triggered slab on a very steep, wind-loaded alpine slope, likely triggered on Thursday (photo in gallery).
On Friday, backcountry travelers reported limited avalanche concerns on the White Salmon Glacier, with dry loose less reactive than the day prior and no wind slabs observed. A handful of wet loose avalanches to D1.5 were seen in gullies on the south aspect of Sefrit and along Nooksack Ridge, though timing was unknown. In the Twin Sisters Range, some wind effect was noted, and warming quickly turned excellent morning conditions into heavier snow and an increase in wet loose activity—even on north aspects—by the afternoon.
Wet avalanches have been limited in size thus far, so the question is whether that changes with continued warming. There’s roughly twice as much new snow sitting over crust compared to the early April warm-up, and it fell in a more concentrated burst. But the earlier period had much warmer conditions—highs in the upper 50s and overnight lows well above freezing. Forecast temperatures this time are cooler, so these competing factors may balance out, hopefully producing a similar level of wet avalanche activity.This information is provided by the U.S.D.A. Forest Service and describes general backcountry avalanche hazard and conditions.
It does not apply to ski areas and highways where avalanche mitigation is conducted.