Turnagain Pass Avalanche Forecast

Boom! Sunshine and springtime avalanche conditions are the name of the game now.  After almost two weeks of rain, snow, strong winds and HIGH hazard the snowpack is stabilizing with clear skies and the temperatures dropping below freezing at night. However, there are still some avalanche problems to consider today. Wet loose avalanches will be possible on steep, solar aspects in the afternoon in the Alpine as the colder drier snow becomes wet. Rocky areas are most suspect. Watch for roller balls. The wet loose avalanches may entrain more snow if they gouge into saturated lower elevation snow. After serious concerns about continued natural wet slab avalanches yesterday with all the saturated snow from the weeks of the rain, observers were happy to report a thick supportable melt-freeze crust up to around 2800′. There was also good evidence that the lower elevation snowpack is draining and overall the possibility of triggering a wet slab has significantly decreased. The surface crust may soften by the afternoon and wet loose avalanches are also possible in the lower elevations late in the day as well. Watch for punchy snow and push-a-lanche conditions in steep terrain.  

Crust @ 1500′  at 11 am became soft and punchy at 4 pm. 3-25-19. 

Between 2800′- 3000′ the snowpack transitions from Spring – supportable crust over moist snow back to Winter (ish) conditions with a drier, colder, deeper snowpack. This colder snow is now getting warmed by direct sunshine and rising temperatures in the Alpine. The warming of the potential slab adds to the lingering concern of triggering an avalanche that fails on an old persistent weak layer. Finding the trigger spot in a thin area could produce a very large avalanche. Signs of instability won’t necessarily be present with this type of avalanche problem. Use good travel protocol and think about consequences if a slope does slide. It could be the 1st or 10th skier or machine on the slope that triggers the avalanche. In addition, if traveling in the Alpine look for areas that are more wind-loaded, watch for cracking and listen/feel for hollow snow indicating wind slabs in upper elevation terrain. 

CORNICES:  Cornices are very large and warm air temperatures and direct sunshine could destabilize them today. They have the potential to trigger very large avalanche on the slopes below and break way farther back than expected. Give them a wide berth. 

Snowpit @ 3100′, March 8th old snow 100 cm below the surface. 3-25-19

There were multiple glide avalanches during the past week and many glide cracks are opening around the advisory area. These are very unpredictable and not triggered by humans. Glide avalanches fail at the ground pulling out the entire season’s snowpack and could be very dangerous. The only way to avoid this hazard is by not spending time under terrain with glide cracks. 

Tincan glide avalanche and cracks, 3-25-19.