Avalanche forecast

West Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
No rating
Open full map
Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

A mix of challenging weather and snow conditions will drive dangerous avalanche conditions through Tuesday. You’re most likely to trigger an avalanche at mid and upper elevations, where new snow, strong winds, and rain-on-snow are rapidly increasing hazard. Snow coverage remains scarce at low elevations.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Wind slab activity will become increasingly likely with rising elevation, strong wind, and greater snow accumulations. Given the uncertainty in current snow coverage and upper elevation condition, this is a dangerous setup. Avalanche danger will be highest at upper elevations on steep, leeward slopes, where rapid loading of new and wind-blown snow has occurred. In more sheltered terrain, storm slab avalanches may also exist.

    As precipitation transitions from rain to snow, slab avalanche activity could spike as the new snow becomes upside down, with heavier snow overlying lighter snow. Take the time to identify wind loaded features, and use small test slopes to pick out instability. If in doubt, stick to terrain below 30 degrees. 

    (3/1/2025)

    A wind slab avalanche on Alta Vista (Paradise area) that occurred on February 25th, last winter season. 

    Photo: Andy Harrington

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    As snow levels rise Tuesday afternoon, rain-on-snow will destabilize any new snow accumulations. Expect an increase in wet avalanche activity as the day progresses. A wet avalanche could occur naturally or be triggered by the weight of a backcountry traveler. This problem will only exist on terrain at or below the rain–snow line. Once surface snow becomes sticky or clumpy, or you feel heavy rain, it’s time to move to lower-angle terrain. 

    (12/13/2025)

    A small fresh wet loose on a steep, SE aspect. There are ski tracks to the left of it, so its hard to say if its skier triggered or natural. 

    Photo: Joe Dellaporta

Avalanche Discussion

At long last, snow levels are expected to drop Monday night into Tuesday morning, allowing for snow accumulations as low as 4,500 feet. By late afternoon, snow levels will rise back up to around 6,000 feet, bringing yet another round of rain-on-snow for low and mid-elevations. Upper elevations, particularly on the volcanoes, will see significant snowfall combined with strong to extreme winds. The West South zone is likely to experience a complex combination of avalanche problems, including wet, dry, loose, slab, or multiple problem types occurring simultaneously. Anyone venturing into the mountains should remain flexible, anticipate rapidly changing conditions, and prioritize safe travel.

At this point, any snow is helpful to open up backcountry recreation. Keep in mind, however, that the majority of low and mid-elevation slopes were completely snow free before any new snow Monday night. Natural hazards (rocks, stumps, logs, etc.) will be shallowly hidden just beneath the surface. We have a long season ahead, so take it easy as you travel in low tide areas. One bad fall can quickly end your winter. Low elevations still don’t have enough snow to pose an avalanche hazard, so no rating is applied.

Mountain access via roads and trailheads continue to be challenging due to recent flood damage. Conditions are unlikely to improve, as extended rainfall may cause further impacts to roadways and waterways. If you’re heading into the backcountry Tuesday, be sure to double-check your route and anticipate potential access issues.

With the warm start to the 25-26 winter season, we have less snowpack information than usual to start daily forecast operations. For zones and elevation bands with less snow than needed for avalanche hazard, we will issue a forecast with No Rating. Anticipated avalanche and weather conditions will still be updated daily. NWAC will issue an avalanche danger rating for a zone when enough snow to produce avalanches has accumulated at middle and upper elevations.

Regions covered