Avalanche Forecast

If you travel in the backcountry today, you must  be certain of your ability to avoid all avalanche terrain. Put a wide buffer of terrain between where you travel and any slopes over 30 degrees. Use extra caution in areas where avalanches could come down from above. Avalanches may be surprisingly large and run farther than you expect.

Watch out for areas where the wind has recently drifted snow. Wind sculpted features, cracks in the snow, pillows, cornices, and variable height of recent snow are all indicators that you could trigger a Wind Slab avalanche. You can trigger Storm Slab avalanches on steep slopes where you find at least 1 foot of recent snow resting on a slick crust. Storm Slabs could break near the surface or involve up to 4 feet of recent snow resting on a slick crust. 

Natural and triggered avalanches were reported Wednesday through Friday from around the West Slopes. On Friday a party was involved in an avalanche in the Snoqualmie Pass backcountry. Skiers and riders triggered numerous slab avalanches in the Bagley Lakes area of the Mt Baker Backcountry. These were all about 1 foot deep and ran in the recent storm snow. Dangerous conditions limited access and observations.

As of late Friday snowfall since the 13th has added up to about 2 feet of snow on the ground. Rain fell up to 3000 feet late Friday. In many areas observers have reported weak sugar-like facets adjacent to a hard, slick crust formed in early February. This combination has been a slick surface and not allowed the recent snow to bond well. You can find these layers 2-4 feet below the snow surface.

On Thursday observers reported a cycle of natural shallow slab avalanches at Snoqualmie Pass. Meanwhile, Loose Dry avalanches were easily triggered in steep terrain on Stevens Pass. These involved snow that fell since February 13th. Backcountry travelers triggered or were caught in avalanches at both Snoqualmie and Stevens Passes.

Observations

On Friday, an NWAC observer in the Mt Baker backcountry reported numerous small triggered slab avalanches in steep terrain near and below treeline. One of these was close to 300 feet wide.

NWAC staff in the field Wednesday and Thursday in the Stevens and Crystal Mt backcountry areas found loose surface snow conditions resulting in numerous loose dry skier triggered avalanches. Wind transported snow was seen to be isolated to exposed features near and above treeline.

At Snoqualmie Pass, NWAC staff and Alpental ski patrol reported natural and triggered slab avalanches in recent snow Wednesday through Friday. On Friday, observer Jeremy Allen reported snowpack tests indicating propagation (Propagation Saw Test) on a crust that was buried February 8th. Dennis D'amico was able to trigger a small storm slab on a steep E-NE test slope at 3900 ft, which ran on the old snow interface 8" down. Matt Schonwald reported many small slab avalanches and about 4 inches of heavy snow on the surface resting on softer recent snow.

On Friday, Forecaster Dallas Glass toured near Paradise on Mt Rainier. He reported 2.5 feet of recent snow on a crust and fresh wind drifts up to 3 feet deep. While no avalanches were reported cracks were observed in recently drifted snow.