Turnagain Pass

The region has received 2″ of rain in the past 24 hrs. The rain fell at least as high as 3000′. Another half an inch of rain is forecasted to fall today up to 2400′. As the water moves into the snowpack it break bonds, adds load and can lubricate weak layers and/or run along crusts, causing large wet slab avalanches. We know we have existing weak layers and crusts buried in the snowpack. Rain may also initiate large wet loose avalanches that could trigger the wet slabs. It is best to visualize the snowpack that has been affected by rain has now turned into a giant, scary slurpee that is out to get you. Avalanches were observed in many paths on Seattle Ridge yesterday and in channeled terrain along the Seward highway. Some of these avalanches were running to the valley bottom. This is very good reason to avoid travel in runout zones. Travel in the mountains is not recommended today. 

Debris in an avalanche path off of Seattle Ridge. 

Fresh debris overrunning old debris in one of the Petersen slide paths. 

                                                         Slurpee Monster 

At higher elevations the precipitation is falling as snow and there were strong winds in the last 24 hrs.  Large storm slabs may have developed in the Alpine depending on how well the new snow bonded to the layer below. Leeward slopes may be very loaded and cornices may be large and tender today. 

The additional load, either from rain or snow combined with high winds, will be stressing the persistent weak layers of snow we know exist in the snowpack. We have two layers of buried surface hoar, a variety of facet/crust combinations and weak faceted at the ground. Avalanches initiating in the upper snowpack may step down to these layers and cause large, deep, dangerous avalanches. 

Snowpack near the skier triggered avalanche that occured on Eddies Monday. Click HERE for full observation.

Eddies avalanche from below.