Avalanche Forecast

Issued: Mar 10th, 2020 11:00AM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low.

Northwest Avalanche Center NWAC, Northwest Avalanche Center

Difficult travel conditions remain the biggest hazard of the day. Many slopes are scoured to bare ice at middle and upper elevations and breakable crusts exist at lower elevations. Choose lower angled slopes with good snow coverage and be confident in your ability to self-arrest before crossing large slopes at higher elevations.

Summary

Discussion

Travel conditions remain variable and challenging with breakable crusts below 5500 ft in the woods and a blue ice layer still exposed on many aspects. On some slopes, the ice layer will be hidden by a thin veneer or fresh snow but remains very dangerous. Don't cross steep icy slopes if you are not confident you can safely self-arrest a fall.

The snow surface is becoming weak with the cold temps and clear nights. Although this won’t change the snow stability today, this will be something to pay attention to as the next weather system arrives later this week.

Snowpack Discussion

March 5, 2020 (The regional synopsis is updated every Thursday @ 6 pm)

Ridgetop wind transport near Washington Pass. 3/4/20 Photo: Josh Hirshberg

 

The beginning of March brought the first spring-like weather to the region. The days are getting longer and the sun (when it shines) has a noticeable effect on the snow. Alternating sun breaks and snowstorms is the theme of the week and the avalanche danger fluctuated just as fast as the weather. The southern zones and the east slopes have seen periods of light snowfall and significant sunshine while the northern zones and west slopes have had significant snowfall and occasional sun breaks. Above freezing temperatures were common at lower elevations throughout the region. 

Last week in review:  Temperatures were above freezing at most trailhead locations and concerns about the previous week’s buried surface hoar and weak layers were fading. Saturday temperatures plummeted as strong winds and new snow built wind slabs in most areas and drove the avalanche danger to considerable in almost every zone. Sunday’s calm weather and clearing in most areas helped stabilize wind slabs, but our attention turned to the strength of the sun and daytime warming. Lingering wind slabs and loose wet avalanches were forecast in every zone. For the remainder of the week, the avalanche problems in every zone were confined to the recent snow and each brief storm cycle had us thinking about wind slabs at upper elevations and loose wet avalanches from daytime warming and sunshine.

Spring isn’t actually here -- another round of cold temps and snow showers are on the way this weekend, but this past week’s oscillating weather is a good reminder to begin to shift our mindset. The sun is gaining strength, the days are getting longer, and we begin daylight savings this week. Even a brief period of sunshine can dramatically alter fresh, new snow. Check the mountain weather and avalanche forecasts for the most up to date info, enjoy the backcountry and let us know what you see out there!

--Peter Moore

Wet loose avalanche debris near Snow Lake. 3/5/20 Photo: Dallas Glass

Fresh cornice development from strong winds in the Stevens Pass backcountry. 3/4/20 Photo: Tom Whipple

Valid until: Mar 11th, 2020 11:00AM