One skier has died and respondents air-lifted another to a nearby hospital after an avalanche on Mount Herman, near Washington’s Mount Baker Ski Area on Sunday. The Northwest Avalanche Center reported the two skiers were caught by the avalanche on the steep north-northwest side of the mountain. The body of the victim has not yet been recovered.

Scott Schell, program director of the NWAC told the Seattle Times the avalanche danger at this time is considered to be moderate, or a 2, on a scale of 1 to 5. However, the danger is heightened by what experts term a "persistent slab"—a persistently weak layer that can fail at any time. The slab was created by layers of frost that formed on January 3 and January 11, and have since been buried by snowfall. "It adds a whole level of uncertainty," he said. NWAC began investigating Monday morning. According to NWAC, this is the seventh avalanche death in the U.S. in the last week.

Meanwhile, just outside the south boundary of Jackson Hole Mountain Resort, two skiers died Sunday afternoon in an avalanche that hit the Rock Springs area. The third member of their group survived. According to Mike Rheam, a forecaster for the Bridger-Teton Avalanche Center, the fracture was reported by patrollers to be two to four feet deep and broke about 200 feet wide. The resort had received about five inches of new snow in the 24 hours before the slide and was wind-blown with unstable slabs.

"The snowpack doesn't know that you're an expert. It's an equal opportunity killer." —Mark Staples, director of the Utah Avalanche Center

Resort spokeswoman Anna Cole told the Jackson Hole News & Guide reportedthat the victims were visitors from out of town. The area where the slide occurred is a popular area just outside the resort boundary. "It's upsetting because these folks, because we don't think they were properly prepared for the backcountry," said Cole. "They didn't have transceivers and they apparently didn't know the terrain very well."

Conversely, a well-prepared and experienced backcountry skier was killed in an avalanche outside Salt Lake City at Gobbler’s Knob in Big Cottonwood Canyon on Thursday, marking the state’s first avalanche fatality of the season. His partner, a longtime backcountry ski guide, was partially buried and survived. Both men were wearing the proper equipment and the deceased deployed his air bag but was overtaken by the avalanche. "The snowpack doesn't know that you're an expert," Mark Staples, director of the Utah Avalanche Center, told the Salt Lake Tribune. "It's an equal opportunity killer."

With snowfall continuing in the Pacific Northwest, the Sierra, and Rockies, check your local avalanche bulletin and talk over the conditions with your ski partners before heading out. According to a study presented at the International Snow Science Workshop in 2012, in the United States, about 70 percent of fatal avalanche accidents occur within four days of the previous accident.