Weak snowpack leads to avalanches, rescues
February 7, 2013
Avalanches swept through Colorado this past weekend as more than 100 slides took place across the state, including one avalanche fatality in the San Juan Mountains.
Search and rescue teams in the Front Range were busy during the weekend with a rescue operation for a woman who became trapped after an avalanche swept her into a steep chute near the summit of Berthoud Pass on Saturday, and numerous avalanches taking place on the East side of Berthoud Pass on Sunday.
The Colorado Avalanche Information Center has issued a special advisory for the Front Range that will be in effect through Wednesday, Feb. 6. The statement reports that the snowpack in the Front Range as well as across Colorado is in a delicate state due to the most recent storm cycle that dropped snow high in moisture content on top of exceptionally weak base layers, creating the potential for large avalanches.
Saturday’s Berthoud rescue
Grand County Search and Rescue and the Alpine Rescue Team from Clear Creek County responded to a report of an avalanche near the summit of Berthoud Pass on Saturday, Feb. 2.
The Grand County Communication Center was contacted by the Colorado State Patrol Dispatch Center at approximately 1:30 p.m. and advised of the avalanche. Initial reports indicated no one was trapped in the avalanche; however, one person was stranded on a rock due to the slide.
Carlotta Fazzone, 49, of Boulder became stranded in a rocky chute after she had triggered an avalanche on the west side of the highway near the summit of the pass.
Alpine Rescue Team was conducting a training at Jones Pass on the east side of Berthoud Pass when mutual assistance was requested by Grand County. Alpine Rescue Team responded quickly with approximately a dozen rescuers being deployed into the field, according to Bill Barwick, a public information officer for the team.
Two members of Grand County Search and Rescue were sent into the field to establish visual and verbal contact with the subject while members of Alpine Rescue Team mobilized a roped rescue.
The subject was retrieved and evacuated from her position in the chute by Alpine Rescue Team members.
Fazzone suffered no injuries and refused medical attention after the incident.
The Grand County Sheriffs Office, Grand County EMS, and the Clear Creek County Sheriff’s Office also had personnel on scene.
“It was great to work with our neighbors from Alpine Rescue Team,” said Kymmie Scott, a public information officer for Grand County Search and Rescue. “We usually have several chances each year to work or train with them and they are very professional.”
Sunday’s avalanche activity
Grand County Search and Rescue and Alpine Rescue Team had another opportunity to work together on Sunday as numerous avalanches were reported on the east side of Berthoud Pass. Grand County Search and Rescue and Alpine Rescue Team responded to the avalanches and reported no burials or injuries.
Colorado, and specifically the Front Range zone, has seen a large increase in the number of avalanches taking place in the backcountry after the most recent storm cycle that swept through the state last week.
“The Front Range zone has seen the most active avalanche cycle [in Colorado] over the weekend,” said Scott Toepfer, a mountain weather and avalanche forecaster with the Colorado Avalanche Information Center. “Even though there have been other avalanches around the state, the problem that remains in the Front Range zone is the weak snow that formed earlier in the year,” Toepfer said.
Weak layers of old snow offer little support to new layers of snow and make for dangerous avalanche conditions.
The snow that moved in with the most recent storm cycle was high in water content, meaning the snow was heavy. It was also accompanied by high winds, which quickly pushed the snow into dangerous slabs that rested on top of layers of weak snow.
This “added a lot of stress to the weak underlying snow layer,” Toepfer said.
These slabs of wet, heavy snow take little stress to create an avalanche. One of the main concerns with the snowpack in the Front Range zone is persistent slabs, or slabs of snow that were created earlier in the year and rest in the middle to lower levels of the snowpack. These slabs have the potential to cut down to the lower levels in the snowpack, even to the ground, if an avalanche is triggered with the potential to create larger, more destructive avalanches.
The avalanche danger will begin to decline over the coming weeks as the new snow begins to settle, but the persistent slabs will linger for some time.
“As this snow pack shows fewer signs of reacting over the coming days, avalanches that could be triggered have the potential to crack wide across the crown and to step down into deeper snow layers,” Toepfer said.
When the new snow begins to settle and the avalanche danger decreases, backcountry skiers could be lulled into a sense of complacency and could drop their guard, Toepfer said. When that happens, skiers may not be prepared or be thinking about big avalanches.
However, it is important to remember that these older slabs of snow still exist in the snowpack and could create large avalanches.
“That weak layer is not going to go away and the top layer will be able to be triggered by human interactions,” Toepfer said.
“When conditions are like they are now, it’s much better to stay clear away from avalanche terrain altogether,” Scott said. “Wait for the pack to solidify before heading back out to the riskier areas and live to play another day.”
Grand County Search and Rescue responded to a report of Barren Lemorande of Denver and Matt Lemorande of Wisconsin who became stranded near the summit of Corona Pass after their Can-Am side by side off-road vehicle became stuck when the left front track broke. The subjects were riding at night when the vehicle became stuck.
One of the subjects was able to place a call on his cell phone requesting help.
Three rescuers rode snowmobiles to where the subjects were stuck and brought the men down from the pass.