Avalanche Forecast

On Wednesday, a shortwave ridge moves across the Pacific Northwest with a temporary decrease in winds and precipitation. This weather should generally allow new or recent storm and wind slab layers to begin stabilizing.

Watch for storm slabs in areas that received more than a few hours of moderate or heavy snowfall intensities. 

Watch for firmer wind-transported snow on lee slopes near ridges, generally northwest through southeast aspects, but watch for it on other aspects in areas of more complex terrain.

Storm or wind slab avalanches may entrain recent snow down to the firmer refreezing snow from last week.

Although they will not be listed as avalanche problems, loose dry avalanches are possible Wednesday, particularly on steep slopes. 

Watch for the numerous travel hazards such as open creeks, barely buried rocks and trees, creating poor and challenging travel conditions, especially below treeline. 

The avalanche danger should generally decrease for all elevation bands on Wednesday.

The great start to the 2017/18 PNW Winter took a giant step backwards last week. Warm, wet weather caused wet snow and glide avalanches and snowpack consolidation with total snow depths decreasing by 50% or more from their mid-November peak depths.

A front and a splitting upper trough crossed the US west coast Sunday and Sunday night. At Hurricane Ridge, the passage of a sharp cold front on Sunday caused south winds in the 20's with gusts to the 40's before changing to westerly in the 10-20 mph range. Temperatures generally dropped from the 40's into the 20's on Sunday afternoon. New snow at Hurricane Ridge was 5" on Monday morning. 

There was some partial clearing at Hurricane Ridge on Monday. 

On Tuesday, a front brought a brief bump in snow levels with the temperature climbing to about 31 degrees at Hurricane Ridge. Winds were generally south in the 10's with gusts in the 30's. By Wednesday morning 24 hour snow totals are expected to be about 5" and the 48 hour total should be about 10".

Observations

NWAC pro-observer Matt Schonwald was out in the Hurricane Ridge area on Saturday. Matt found pockets of wind slab up to 15 cm (6") thick on north aspects of Mt. Angeles near 5000 feet. Wind slabs were stubborn to trigger and did not propagate.  A few glide cracks were visible in the Hurricane Ridge area, but the only large slide observed from the recent rain events was noted off the south side of Mt. Angeles. Windward slopes above treeline were largely stripped of snow.    

The ranger at Hurricane Ridge on Monday morning reported no avalanche activity.