Avalanche Forecast

You will be able to trigger a large Wind Slab on Monday with increasing danger as the day progresses.

Light snow will combine with moderate winds to build on top of older and still healing soft wind slabs that formed Friday through Saturday, likely adding to their instability and potentially rejuvenating the problem. These slabs are most likely to be found at higher elevations on Monday, where cold temperatures likely slowed the healing process of these slabs. Navigate around larger terrain features and steeper slopes near and above treeline that are either actively loading or may have been loaded earlier in the week. And dial back your terrain selection as winds increase on Saturday.

Storm Slabs will be possible to trigger as higher density snow falls on the recent lower-density snow, creating a slab. Watch for this problem to develop later in the day and observe visual clues such as cracking of the surface snow to detect slab formation. With 1.5-2' of recent dry snow to work with on northerly aspects, even a shallow slab could entrain significant snow and run farther than you expect.

Mid-to-upper elevation stations at Mt. Hood have seen 2-4" of snowfall on Sunday and increasing winds were likely transporting the low density snow.

Around 12-14" of new snow fell in the Mt Hood area Friday through Saturday at temperatures in the low 10's to low 20's generally and snowfall during the day Saturday was generally light. Moderate winds during this period blew low-density snow on top of lower density snow to create a widespread very soft wind slabs, particularly above treeline and were quite reactive to trigger and in some cases remote trigger both Friday and Saturday. These were identified within the ski area and on south-facing back-country terrain.

Wednesday and Thursday witnessed lighter amounts of snow falling on a cooling trend. Temperatures have stayed cold since last Wednesday night, which was the last time temperatures were above freezing at Mt. Hood Meadows base.

Weather stations indicate that rain reached around 6000’ on Wednesday night before lowering freezing levels brought a transition to snow. Cooling temperatures throughout the storm created a generally good bond to old snow surfaces.

The new snow and wind slabs fell on a variety of snow surfaces. On southerly aspects a firm and thick melt-freeze crust can be found that formed during sunny weather March 10-12, which helped to consolidate and strengthen the snowpack. On more shaded slopes a thinner and weaker crust can be located below the new snow.

While we are tracking several layers deeper in the snowpack, there are currently no significant layers of concern.

Observations

On Saturday, MHM pro patrol reported many small to large skier-triggered and explosive-triggered soft slab avalanches near and above treeline. Some were remote-triggered. The problem described was a soft wind slab.

On Saturday, snow professionals traveled in the Newton drainage and found 1 foot of high quality new snow. Winds had created loose, but not reactive wind deposits. Near and above treeline, back-country travelers reported south-facing slopes were forming slabs and becoming more reactive.

On Friday NWAC professional observer Laura Green traveled in the Mt Hood backcountry. Laura reported small soft slabs in the near and above treeline band.

On Thursday, MHM pro patrol reported 8-12” (20-30cm) wind slabs avalanches during avalanche control work.