Avalanche Forecast

On Sunday, no new avalanches were observed in the Hurricane Ridge area, but additional observations of recent natural slab avalanches from Friday/Saturday filtered in with improved access and visibility. Hurricane Ridge recorded a whopping 33” of snow over the 48 hours ending Saturday morning. Above 4000-4500’, this storm has filled in what had been a meager snowpack with an average height of snow in the Hurricane Ridge area over 3 ft. Below 4000’ a thin snow pack still exists. 

Below treeline, low snow means that rocks, stumps, creeks and other hazards are still present, so travel carefully as you drop down in elevation. 

Forecast Schedule

For the 2019-20 winter season, avalanche danger ratings will be issued for the Olympics every Friday through Sunday and during mid-week holidays. During the week, No Rating will be issued but forecasts will include expected conditions and relevant travel advice.  If you are out in the Olympics, share your backcountry observations with us and the greater community.

December 19th, 2019 (The regional synopsis is updated every Thursday @ 6 pm)

Let’s take a moment to recap what happened over the past week:

A potent winter storm arrived on the 12th, adding to the very shallow snowpack throughout the region. Anywhere from 6-36” of snow fell between the 11th and 15th. Places like Mt Baker, Paradise, Mt Hood, and White Pass were the winners regarding snowfall, with quite a bit less for areas further east of the crest like Mission Ridge, Blewett Pass, and Washington Pass. 

The most notable avalanche activity occurred in the Mt. Baker backcountry where numerous human triggered storm slab avalanches occurred (with several big enough to injure, bury, or kill a person). The majority of these occurred on upper elevation, north and east facing terrain. Besides the danger posed by the size of the avalanche, many slides quickly revealed rocks and other obstacles barely hidden below the snow surface. 

The storm layer took time bond with the underlying snow surface, and we saw the likelihood of triggering slab avalanches slowly decrease over a handful of days. The avalanche danger was at Considerable for many places on Saturday the 14th, then tapered to Moderate on Sunday, and eventually reached Low in many places by Tuesday and Wednesday. 

A large, human triggered avalanche on the old snow interface. East aspect of Table Mountain (West-North Zone) at 5,500ft. December 15,2019. Photo by Brooks Broom. 

Backcountry travelers have noted generally thin and shallow snowpacks, with a range of structures across the region. Many folks were skeptical of the layering they found. People were able to dig down and observe weak layers in many areas. These were buried in late November and early December. In some places they presented as weak snow over a crust, in others, a layer of feather-like surface hoar. Cold temperatures have likely preserved many of these layers, and will be worth considering as the snow piles up.

Below is a list of commonly visited locations and their snowpack depths in inches (as of December 19th at 4am). Check the weather station hourly data feed and watch as the subtropical javelin of moisture (also known as a strong atmospheric river) changes conditions dramatically over the next few days. 

Total Snow Depth in Inches as of December 19th at 04:00 AM.

-Matt Primomo