Turnagain Pass

The glide avalanche cycle continues with new activity occurring on a daily basis. Springtime weather, warm temperatures and rain, continues to add stress to the mid-elevation snowpack where the majority of glide cracks exist. If venturing into the mountains choose your route wisely. It is very important to identify terrain with existing cracks and avoid any travel under the runout of glides.

A view yesterday of Repeat Offender on Seattle Ridge. Even though this area has closed to motorized use, travel on the Seattle Ridge side of the road is still not recomended.

Close up of existing glide cracks that still threaten the normal “skin route” to Seattle Ridge.

Over the last 48 hours 0.8” (Snow Water Equivalent) has fallen in Turnagain Pass. This is equal to about 3-5” of wet/moist snow in the mid elevations (1800’-2500’) and rain below this. Today’s showery weather will likely add another 3-5” of wet snow to the mid elevation band. Below 2500’ human triggered wet loose avalanches are likely, if initiated on steeper slopes. In general avoid steep terrain if the surface snow is wet or older snow (where it has been raining) is unsupportable. These are obvious clues the snow is loosing its strength.

*In the alpine where drier snow has fallen over the week, solar exposure will be important to monitor should the sun appear.  With warm springtime temperatures, any period of direct sun could rapidly melt surface snow, and natural wet loose activity will be possible. 

Visibility has been very poor in Turnagain over the last few day, however the DOT webcam captured a photo of wet loose activity on Tincan’s CFR ridge during a brief clearing Tuesday(4/26) evening. 

Over the last four days an estimated 1-2’ of new snow has fallen in the alpine with periods of strong winds earlier in the week. Today Moderate Easterly ridgetop winds are expected with an additional 5” of new snow. Be on the look out for wind slabs on leeward features. Careful snowpack evaluation is essential in the alpine, and don’t forget blowing snow and cracking underfoot are obvious signs the snowpack is stressed out. The wind and snow may also have added stress to very large cornices. Avoid being under cornices and give them extra space along ridgelines.