The ACMG Training and Assessment Program spent the past week in both Frisby Creek and Rogers Pass backcountry. Below is a quick summary of our observations.

Frisby Creek April 15th-18th: The week began with generally good weather, few clouds, and cool temperatures transitioning to unsettled weather with overcast and obscured skies starting on Saturday delivering 50+cms of new snow. Freezing levels remained below 1700m throughout the exam with daytime highs near 3 and overnight lows around -6. Generally winds remained light-moderate from the S-SE during our time in Frisby Creek.

Objectives in Frisby Creek included: Birthday Peak, Birgitta Peaks, Shrund Peak, Shred Peak.

Frisby Creek Snowpack: 40-50cms of new snow was being redistributed by moderate gusting to strong southerly winds creating touchy wind slabs/storm slabs in lee features. Intense solar input on April 17 created moist snow on all aspects except due North and freezing levels rose to 1700m. The new snow is sitting on a series of April layers most notably the April 6th (facets/grouple/suncrust) found down 50-70cms in our test pits. The March 31st (down 80-100cms) suncrust was the most problematic on solar aspects creating easy test results with good propagation potential as well as lots of spooky whumfing. This limited our travel on solar aspects to low angle non avalanche terrain and was a primary factor in our decision to change locations.

Frisby avalanche activity: We observed a widespread natural cycle to size 3 during the April 16 storm. April 17 we observed a skier remote size 2.5. Most avalanches were observed on lee features in alpine areas. We also observed numerous previous glide crack avalanches to size 2 and loose wet activity from southerly aspects at TL and many areas BTL.

Rogers Pass April 19th&20th: We started out with overcast skies and calm conditions making for a pronounced green house effect creating moist surfaces and subsequent crusts on all aspects to 2100m. On Thursday we were greeted with clear skies and a good overnight refreeze making for fast travel. Continued katabatic winds throughout the day kept the temps near zero despite the sunny conditions.

Objectives in Rogers Pass included: Bonney Glacier, Sapphire Col, Lily Glacier, Dome Glacier, Young’s traverse via the Illiceliweat.

Rogers Pass Snowpack: 15-20cm of HST redistributed by moderate southerly and down flow winds in the alpine overlies a variety of April interfaces. Most notably the April 9th melt freeze crust down 5-30 cms below 2000m, and the March 31st (isolated surface hoar, facets, and suncrust) layer down 40-70cm. Dry snow exists above 2200m on polar aspects while solar aspects in the alpine, tree line, and below are moist in the pm. Spring diurnal in effect below 1700m.

Rogers Pass avalanche activity: Evidence of previous wind slab activity from the April 16 storm and previous loose wet cycle. On April 20 we observed loose wet activity on steep southerly alpine areas due to clear skies and intense solar inputs.

Other hazards on our radar included large overhead cornices, glide cracks/slabs and open creeks in the valley bottom as well as un-skiable breakable crusts. The November deep persistent avalanche problem was also a concern and something to keep in mind as we transition to spring.

Stay safe and have fun!

Mike Adolph, Todd Craig, Erica Roles and the SGE 3 candidates.