Avalanche Forecast

Partial clearing Saturday night along with cool temperatures, should allow any moist to wet snow to re-freeze and form a thin crust layer, especially near and below treeline on all but steep northerly facing terrain. 

The next frontal precipitation is expected to arrive late Sunday morning and gradually increase along with ridgetop winds through the afternoon. Shallow new wind slabs may become locally sensitive in areas that receive rapid accumulations Sunday afternoon.  

Recent winds have been mostly SE-SW so firmer wind slab should be found mainly on NW-N-SE slopes near and above treeline. Expected increasing winds Sunday should be similar, mostly S-SW.

Recent cornices are very large. Make sure to avoid areas on ridges where there may be an overhanging cornice as well as travel on steep slopes below cornices! Natural cornice releases and resulting slab avalanches are unpredictable. See a blog post regarding cornices here.

Weather and Snowpack

The first week or so of March was very cool and snowy.  NWAC stations at Mt Hood piled up about 6-7 ft of snow.

The 2nd week of March was equally active with non-stop Pacific frontal systems pummeling the PNW. Unfortunately, these systems delivered far more rain than snow. At least two regional avalanche cycles occurred during the stretch. Significant snowpack consolidation occurred over this period due to rainfall and warmer temperatures. 

This past week has also been active weather-wise, but water amounts/snowfall totals have been slightly lower relative to the extreme wetness of the past few weeks. In the last 24 hours ending at 5 PM Friday, Mt. Hood stations have picked up 7-9" of snow above 5000'. A slight warming trend occurred during the day on Friday. Winds above treeline have been moderate out of the S-SW.  

Recent Observations

On Thursday, Mt. Hood Meadows reported widespread, but stubborn shallow hard wind slab, 1-2 ft deep, on the NE slopes between 6000 and 7300 ft. Small loose wet slides remained possible on steeper solar slopes. By Friday, 6-12" storm slabs were sensitive to ski cuts specifically on N-E aspects above treeline. Storm slabs were relatively less reactive near treeline. 

Laura Green was out in the Timberline area on Friday. Moderate winds, wet snow and poor visibility prevented her from accessing terrain above 6500 feet, but she could see active wind transport occurring in the elevations she traveled. 1 natural wet slab, 20 cm deep, was observed below treeline but in general the rain moistened snow below treeline was not very sensitive to human triggering and no other natural wet snow activity was observed. 

Mt Hood patrol were unable to reach terrain above treeline Saturday due to winds and poor visibility. Near treeline, a few triggered wind slabs were able to be released with skis, but were only 1-2 inches deep. Large cornice releases at higher elevations may have released avalanches on the slopes below, but this was unconfirmed due to visibility.

Below treeline, shallow surface snow was producing Rollerballs and small loose-wet slides Saturday afternoon during extended sun breaks.