Avalanche forecast

West Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Warm and sunny weather with the highest temperatures of the season will rapidly weaken the snow surface on Sunday and increase the likelihood for you to trigger loose wet avalanches. When you begin to find wet and punchy snow or see fresh teardrop-shaped slides, seek out firmer snow surfaces or lower angled terrain.

Avalanche problems

  • Loose Wet

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

    Another warm and sunny day will quickly soften any crust that develops overnight. As the surface weakens you may trigger loose wet avalanches on steep slopes over 35 degrees. When you begin to sink into the snow past your ankle or you see snow naturally rolling downhill, it’s time to change locations. Find more frozen or lower angled terrain to stay ahead of the loose wet hazard. Easterly slopes will soften quickly in the morning before wet snow spreads to other aspects and onto the northern half of the compass dial. Anticipate this rapid change and plan to travel early before unstable snow becomes more widespread. Later in the day, you could see natural wet avalanches as water impacts more of the upper snowpack. With the current conditions, these slides could entrain snow, grow large, and travel far downslope.

    (4/15/2021) When you find a wet, sticky, and punchy snow surface like this you may trigger loose wet avalanches on similar slopes. New rollerballs are also present on the slope.

Avalanche Discussion

While the West-South zone has experienced warm temperatures recently, moderate to strong easterly winds have helped limit the pooling of water at the snow surface. This is no longer the case as the winds have calmed and temperatures will reach the highest of the season on Sunday. Locations on Mt Rainier and Mt St Helens experienced are now experiencing the 4th day with poor overnight freezes. Consequently, you could encounter locally more dangerous conditions in these areas with larger and more abundant natural avalanches. 

Predicting the timing of these spring-time avalanche cycles is tricky. Small to large natural wet avalanches were observed Saturday and should be likely again Sunday. Pay attention to the terrain above you. Choose routes that reduce the amount of time you spend below rocky faces, slopes with crevasse-like glide cracks, and overhanging cornices. As temperatures warm up, snow tends to fall down. Make sure your travel plans leave you with plenty of options to reduce your exposure and change plans if you begin to see more natural avalanche activity than expected. 

This is the final full avalanche forecast product of the 2020-21 season. As our capacity thins during the warmer months, please continue to share your observations and make use of our mountain weather forecasts (daily through the end of April). From all the forecasters at NWAC, thank you for all your support that makes this product possible and we look forward to resuming full operations in late 2021.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regions covered