Avalanche Forecast

A marine push Friday night should pull some low clouds up against the west slopes of the Cascades Saturday morning but in general, mostly sunny, warm temperatures and generally light winds are expected Saturday. Freezing levels and temperatures should lower a notch on Saturday. As a result, the avalanche danger should lower slightly Saturday but still land firmly in the Moderate range. Get off steep slopes early in the day and be aware of the overhead hazard to minimize your exposure. 

Loose wet avalanches will be possible on any steeper slope due to warming Saturday. Pay attention to the integrity of surface crusts formed overnight. Backcountry travel early in the day is recommended since conditions can change rapidly due to daytime warming. Watch for wet snow deeper than your boot tops especially on steep solar slopes during the late morning to afternoon hours.

The potential for cornice releases will continue on Saturday. Cornice releases can be unpredictable during the spring so avoid areas below cornices and remember that cornices can break much further back than expected along ridges.

Although not listed as an avalanche problem, large, powerful glide avalanches can release unexpectedly so avoid areas below steep unsupported slopes or rock faces.

Avalanche activity on Saturday is not expected to be as extensive as during the warm weather last week which more closely followed a period of heavier snowfall and caused consolidation and some stabilizing. Hence the Moderate avalanche rating in all areas versus the Considerable rating forecast last week. You will need to evaluate avalanche conditions on specific terrain features and change your plans if snow conditions are more dangerous than expected.

Weather and Snowpack

A large upper ridge dominated the weather last week through early Sunday, resulting in very warm and dry weather. A spring avalanche cycle occurred in most areas over this stretch, likely peaking Thursday or Friday during the warmest temperatures and lightest winds. After a stormy March, the snowpack has undergone significant settlement and multiple melt-freeze cycles over the last week.

A front moved across the Mt Hood area early Monday morning, resulting in a period of moderate precipitation, cooling and moderate to strong westerly crest level winds. Precipitation transitioned from rain to snow as cooling occurred, forming a generally good bond to the old melt freeze crust. Showers at cooling temperatures occurred overnight Monday and Monday night. Storm snow amounts on Mt Hood ranged from 6-12 inches as of Tuesday.

Another upper ridge is currently over the Northwest causing sunny weather and warm temperatures with most NWAC stations on Mt. Hood pushing into the 50s and 60s Thursday and Friday! 

Frequent March storms have built large cornices along many ridges.

The mid and lower snowpack along the west slopes should generally be a stable mix of crusts and layers of moist and rounded snow crystals.

Recent Observations

Following the recent snowfall Monday and Monday night, on Tuesday 4/5 the Meadows pro-patrol reported only isolated avalanche results. Moderate to strong winds appeared to have displaced much of the storm snow, rather than building wind slabs in the typical places, hence only isolated results were achieved and those from large explosives. Good bonding of recent snow was also noted with the old moist surface.

Mid-day on Wednesday 4/6 the Meadows pro-patrol reported no avalanches within the ski area but some triggered loose wet avalanches on the upper mountain.

After a quiet day Thursday, Meadows pro-partol reported a thin melt-freeze crust quickly breaking down Friday morning. The gamut of wet snow avalanches were observed Friday due to the warmth; small loose wet on steeper solar slopes, partial cornice failures and even a small glide avalanche above a rock face on an east aspect at 5500'.